<s>
Home	O
computers	O
are	O
the	O
second	O
generation	O
of	O
desktop	B-Device
computers	I-Device
,	O
entering	O
the	O
market	O
in	O
1977	O
and	O
becoming	O
common	O
during	O
the	O
1980s	O
.	O
</s>
<s>
A	O
decade	O
later	O
they	O
were	O
generally	O
replaced	O
by	O
IBM	O
PC	O
compatible	O
"	O
PCs	B-Device
"	O
,	O
although	O
technically	O
home	O
computers	O
are	O
also	O
classified	O
as	O
personal	B-Device
computers	I-Device
.	O
</s>
<s>
Examples	O
of	O
typical	O
early	O
home	O
computers	O
are	O
the	O
TRS-80	B-Device
,	O
Atari	B-Device
400/800	I-Device
,	O
BBC	B-Device
Micro	I-Device
,	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
,	O
the	O
MSX	B-Operating_System
1	I-Operating_System
,	O
the	O
Amstrad	B-Device
CPC	I-Device
464	I-Device
and	O
the	O
Commodore	O
64	O
.	O
</s>
<s>
Examples	O
of	O
typical	O
late	O
home	O
computers	O
are	O
MSX	B-Operating_System
2	I-Operating_System
systems	O
,	O
and	O
the	O
Amiga	B-Device
and	O
Atari	B-Device
ST	I-Device
systems	O
.	O
</s>
<s>
Note	O
:	O
in	O
cases	O
of	O
manufacturers	O
who	O
have	O
made	O
both	O
home	O
and	O
personal	B-Device
computers	I-Device
,	O
only	O
machines	O
fitting	O
into	O
the	O
home	O
computer	O
category	O
are	O
listed	O
.	O
</s>
<s>
Systems	O
in	O
the	O
personal	B-Device
computer	I-Device
category	O
,	O
except	O
for	O
Early	O
Macintosh	B-Device
PCs	B-Device
,	O
are	O
generally	O
based	O
on	O
the	O
VGA	B-Protocol
standard	O
and	O
use	O
a	O
video	B-General_Concept
chip	I-General_Concept
known	O
as	O
a	O
Graphics	B-Architecture
Processing	I-Architecture
Unit	I-Architecture
.	O
</s>
<s>
Very	O
early	O
PCs	B-Device
used	O
one	O
of	O
the	O
much	O
simpler	O
(	O
even	O
compared	O
to	O
most	O
home	O
computer	O
video	O
hardware	O
)	O
video	B-General_Concept
display	I-General_Concept
controller	I-General_Concept
cards	O
,	O
using	O
parts	O
like	O
the	O
MDA	B-Device
,	O
the	O
Hercules	B-Device
Graphics	I-Device
Card	I-Device
,	O
the	O
CGA	B-Device
and	O
the	O
EGA	B-Device
standard	O
)	O
.	O
</s>
<s>
Only	O
after	O
the	O
introduction	O
of	O
the	O
VGA	B-Protocol
standard	O
could	O
PCs	B-Device
really	O
compete	O
with	O
the	O
home	O
computers	O
of	O
the	O
same	O
era	O
,	O
such	O
as	O
the	O
Amiga	B-Device
and	O
Atari	B-Device
ST	I-Device
,	O
or	O
even	O
with	O
the	O
MSX-2	O
.	O
</s>
<s>
Also	O
,	O
not	O
listed	O
are	O
systems	O
that	O
are	O
typically	O
only	O
gaming	O
systems	O
,	O
like	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
and	O
the	O
Bally	B-Device
Astrocade	I-Device
,	O
even	O
though	O
these	O
systems	O
could	O
sometimes	O
be	O
upgraded	O
to	O
resemble	O
a	O
home	O
computer	O
.	O
</s>
<s>
Early	O
home	O
computers	O
all	O
used	O
similar	O
hardware	O
and	O
software	O
,	O
mostly	O
using	O
the	O
6502	B-General_Concept
,	O
the	O
Z80	B-General_Concept
,	O
or	O
in	O
a	O
few	O
cases	O
the	O
6809	B-Device
microprocessor	O
.	O
</s>
<s>
They	O
could	O
have	O
as	O
little	O
as	O
1	O
KB	O
of	O
RAM	B-Architecture
or	O
as	O
much	O
as	O
128K	O
,	O
and	O
software-wise	O
,	O
they	O
could	O
use	O
a	O
small	O
4K	O
BASIC	O
interpreter	O
,	O
or	O
an	O
extended	O
12K	O
or	O
more	O
BASIC	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
built-in	O
BASIC	O
interpreter	O
lacked	O
any	O
sort	O
of	O
graphics	O
commands	O
,	O
as	O
it	O
was	O
the	O
same	O
version	O
that	O
was	O
developed	O
for	O
the	O
older	O
Commodore	B-Device
PET	I-Device
(	O
a	O
computer	O
without	O
any	O
high-resolution	O
graphics	O
capabilities	O
at	O
all	O
)	O
.	O
</s>
<s>
However	O
,	O
these	O
drawbacks	O
were	O
of	O
little	O
consequence	O
,	O
because	O
the	O
C64	O
had	O
the	O
VIC-II	O
chip	O
.	O
</s>
<s>
When	O
accessed	O
by	O
machine	B-Language
language	I-Language
programs	O
,	O
the	O
graphic	O
capabilities	O
of	O
this	O
chip	O
made	O
it	O
practical	O
to	O
develop	O
arcade-style	O
games	O
on	O
a	O
home	O
system	O
.	O
</s>
<s>
Additionally	O
,	O
specific	O
machine	B-Language
language	I-Language
code	O
exploiting	O
quirks	O
of	O
the	O
VIC-II	O
chip	O
allowed	O
for	O
special	O
tricks	O
to	O
draw	O
even	O
better	O
pictures	O
out	O
of	O
the	O
VIC-II	O
chip	O
.	O
</s>
<s>
An	O
example	O
of	O
the	O
opposite	O
is	O
the	O
Aquarius	B-Device
by	O
Mattel	O
which	O
had	O
such	O
incredibly	O
limited	O
video	O
hardware	O
that	O
it	O
was	O
retracted	O
from	O
the	O
market	O
after	O
only	O
four	O
months	O
due	O
to	O
poor	O
sales	O
.	O
</s>
<s>
The	O
problem	O
was	O
determining	O
a	O
way	O
to	O
give	O
both	O
the	O
video	O
hardware	O
(	O
VDU	O
)	O
and	O
the	O
CPU	B-Device
continuous	O
read	O
access	O
to	O
the	O
video	O
RAM	B-Architecture
.	O
</s>
<s>
The	O
obvious	O
solution	O
,	O
using	O
interleaving	B-Protocol
time	I-Protocol
slots	I-Protocol
for	O
the	O
VDU	O
and	O
RAM	B-Architecture
was	O
hard	O
to	O
implement	O
because	O
the	O
logic	O
circuits	O
and	O
video	O
memory	O
chips	O
of	O
the	O
time	O
did	O
not	O
have	O
the	O
switching	O
speed	O
necessary	O
to	O
do	O
so	O
.	O
</s>
<s>
For	O
higher	O
resolutions	O
,	O
the	O
logic	O
and	O
the	O
memory	O
chips	O
were	O
barely	O
fast	O
enough	O
to	O
support	O
reading	O
the	O
display	O
data	O
,	O
let	O
alone	O
for	O
dedicating	O
half	O
the	O
available	O
time	O
for	O
the	O
slow	O
8-bit	O
CPU	B-Device
.	O
</s>
<s>
That	O
being	O
said	O
,	O
one	O
system	O
,	O
the	O
Apple	B-Device
II	I-Device
,	O
was	O
one	O
of	O
the	O
first	O
to	O
use	O
a	O
feature	O
of	O
the	O
data-bus	O
logic	O
of	O
the	O
6502	B-General_Concept
processor	I-General_Concept
to	O
implement	O
a	O
very	O
early	O
interleaving	O
time	O
slot	O
mechanism	O
to	O
eliminate	O
this	O
problem	O
.	O
</s>
<s>
The	O
BBC	B-Device
Micro	I-Device
used	O
4MHz	O
RAM	B-Architecture
with	O
a	O
2MHz	O
6502	B-General_Concept
in	O
order	O
to	O
interleave	O
video	O
accesses	O
with	O
CPU	B-Device
accesses	O
.	O
</s>
<s>
Most	O
other	O
systems	O
used	O
a	O
much	O
simpler	O
approach	O
,	O
and	O
the	O
TRS-80	B-Device
'	O
s	O
video	O
logic	O
was	O
so	O
primitive	O
that	O
it	O
simply	O
did	O
not	O
have	O
any	O
bus	O
arbitration	O
at	O
all	O
.	O
</s>
<s>
The	O
CPU	B-Device
had	O
access	O
to	O
the	O
video	O
memory	O
at	O
all	O
times	O
.	O
</s>
<s>
Writing	O
to	O
the	O
video	O
RAM	B-Architecture
simply	O
disabled	O
the	O
video	O
display	O
logic	O
.	O
</s>
<s>
The	O
result	O
was	O
that	O
the	O
screen	O
often	O
displayed	O
random	O
horizontal	O
black	O
stripes	O
on	O
screen	O
when	O
there	O
was	O
heavy	O
access	O
to	O
the	O
video	O
RAM	B-Architecture
,	O
like	O
during	O
a	O
video	O
game	O
.	O
</s>
<s>
Most	O
systems	O
avoided	O
the	O
problem	O
by	O
having	O
a	O
status	B-General_Concept
register	I-General_Concept
that	O
the	O
CPU	B-Device
could	O
read	O
,	O
and	O
which	O
showed	O
when	O
the	O
CPU	B-Device
could	O
safely	O
write	O
to	O
the	O
video	O
memory	O
.	O
</s>
<s>
That	O
was	O
possible	O
because	O
a	O
composite	O
video	B-Application
signal	I-Application
blanks	O
the	O
video	O
output	O
signal	O
during	O
the	O
"	O
blanking	O
periods	O
"	O
of	O
the	O
horizontal	O
and	O
especially	O
the	O
long	O
vertical	O
video	O
sync	O
pulses	O
.	O
</s>
<s>
If	O
the	O
software	O
ignored	O
the	O
status	B-General_Concept
register	I-General_Concept
the	O
stripes	O
would	O
re-appear	O
.	O
</s>
<s>
Another	O
approach	O
,	O
used	O
by	O
most	O
other	O
machines	O
of	O
the	O
time	O
,	O
was	O
to	O
temporarily	O
stop	O
the	O
CPU	B-Device
using	O
the	O
"	O
WAIT/BUSRQ	O
"	O
(	O
Z80	B-General_Concept
)	O
"	O
WAIT	O
"	O
(	O
6809	B-Device
)	O
or	O
"	O
SYNC	O
"	O
(	O
6502	B-General_Concept
)	O
control	O
signal	O
whenever	O
the	O
CPU	B-Device
tried	O
to	O
write	O
to	O
the	O
screen	O
during	O
a	O
non-blanking	O
period	O
.	O
</s>
<s>
Yet	O
another	O
,	O
more	O
advanced	O
,	O
the	O
solution	O
was	O
to	O
add	O
a	O
hardware	O
FIFO	B-Operating_System
so	O
that	O
the	O
CPU	B-Device
could	O
write	O
to	O
the	O
FIFO	B-Operating_System
instead	O
of	O
directly	O
to	O
the	O
RAM	B-Architecture
chips	I-Architecture
,	O
which	O
were	O
updated	O
from	O
the	O
FIFO	B-Operating_System
during	O
a	O
blanking	O
interval	O
by	O
special	O
logic	O
circuitry	O
.	O
</s>
<s>
Some	O
later	O
systems	O
started	O
using	O
special	O
"	O
two-port	O
"	O
video	O
memory	O
,	O
called	O
VRAM	O
,	O
that	O
had	O
independent	O
data	O
output	O
pins	O
for	O
the	O
CPU	B-Device
interface	O
and	O
the	O
video	O
logic	O
.	O
</s>
<s>
There	O
are	O
two	O
main	O
categories	O
of	O
solutions	O
for	O
a	O
home	O
computer	O
to	O
generate	O
a	O
video	B-Application
signal	I-Application
:	O
</s>
<s>
Simple	O
video	O
shift	B-General_Concept
register	I-General_Concept
based	O
solutions	O
,	O
have	O
a	O
simple	O
"	O
video	O
shifter	O
chip	O
"	O
,	O
and	O
the	O
main	O
CPU	B-Device
doing	O
most	O
of	O
the	O
complex	O
stuff	O
.	O
</s>
<s>
Only	O
one	O
example	O
of	O
such	O
a	O
chip	O
for	O
a	O
home	O
computer	O
exists	O
,	O
the	O
RCA	O
CDP1861	O
used	O
in	O
the	O
COSMAC	B-Device
VIP	I-Device
.	O
</s>
<s>
Dedicated	O
Video	O
shifter	O
chips	O
did	O
have	O
some	O
use	O
in	O
very	O
early	O
game	O
systems	O
,	O
most	O
notably	O
the	O
Television	B-General_Concept
Interface	I-General_Concept
Adapter	I-General_Concept
chip	O
in	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
.	O
</s>
<s>
Note	O
that	O
although	O
one	O
of	O
the	O
chips	O
in	O
an	O
Atari	B-Device
ST	I-Device
is	O
also	O
called	O
a	O
"	O
video	O
shift	B-General_Concept
register	I-General_Concept
"	O
it	O
does	O
not	O
fall	O
into	O
this	O
class	O
,	O
mainly	O
because	O
the	O
IC	O
's	O
in	O
this	O
class	O
depends	O
on	O
the	O
main	O
CPU	B-Device
to	O
feed	O
them	O
with	O
picture	O
data	O
.	O
</s>
<s>
The	O
Atari	B-Device
ST	I-Device
's	O
chip	O
used	O
a	O
DMA	O
system	O
to	O
read	O
out	O
video	O
data	O
independent	O
of	O
the	O
main	O
CPU	B-Device
and	O
contained	O
a	O
palette	B-Data_Structure
RAM	B-Architecture
,	O
and	O
resolution/color	O
mode	O
switching	O
logic	O
.	O
</s>
<s>
CRTC	O
(	O
Cathode	O
Ray	O
Tube	B-Device
Controller	O
)	O
based	O
solutions	O
.	O
</s>
<s>
It	O
must	O
be	O
complemented	O
with	O
some	O
"	O
Video	O
RAM	B-Architecture
"	O
and	O
some	O
other	O
logic	O
for	O
the	O
"	O
arbitration	O
"	O
so	O
that	O
the	O
CPU	B-Device
and	O
the	O
CRTC	O
chip	O
can	O
share	O
access	O
to	O
this	O
RAM	B-Architecture
.	O
</s>
<s>
For	O
example	O
,	O
a	O
ROM	B-Device
containing	O
the	O
bitmap	O
font	O
for	O
text	B-Application
modes	I-Application
,	O
and	O
logic	O
to	O
convert	O
the	O
output	O
from	O
the	O
system	O
into	O
a	O
video	B-Application
signal	I-Application
.	O
</s>
<s>
The	O
VIC-II	O
chip	O
is	O
probably	O
the	O
best-known	O
chip	O
of	O
this	O
category	O
.	O
</s>
<s>
Video	O
co-processor	O
chips	O
are	O
at	O
the	O
highest	O
end	O
of	O
the	O
scale	O
;	O
Video	O
interface	O
controllers	O
that	O
can	O
manipulate	O
,	O
and/or	O
interpret	O
and	O
display	O
,	O
the	O
contents	O
of	O
their	O
own	O
dedicated	O
Video	O
RAM	B-Architecture
without	O
intervention	O
from	O
the	O
main	O
CPU	B-Device
.	O
</s>
<s>
These	O
chips	O
are	O
highly	O
flexible	O
offering	O
options	O
and	O
features	O
with	O
minimal	O
CPU	B-Device
involvement	O
that	O
on	O
other	O
systems	O
are	O
impossible	O
or	O
at	O
best	O
difficult	O
to	O
produce	O
,	O
requiring	O
extensive	O
CPU	B-Device
overhead	O
.	O
</s>
<s>
The	O
Atari	O
ANTIC/GTIA	O
and	O
Amiga	B-Device
OCS/ECS/AGA	O
are	O
well	O
known	O
examples	O
of	O
this	O
high-feature	O
category	O
.	O
</s>
<s>
But	O
note	O
that	O
not	O
all	O
video	O
co-processors	O
are	O
powerful	O
,	O
some	O
are	O
even	O
simpler	O
than	O
many	O
Video	O
interface	O
controllers	O
,	O
notably	O
the	O
primitive	O
SAA5243	B-General_Concept
which	O
is	O
still	O
technically	O
a	O
co-processor	O
.	O
</s>
<s>
Video	O
RAM	B-Architecture
The	O
maximum	O
amount	O
of	O
RAM	B-Architecture
used	O
for	O
the	O
video	O
display	O
,	O
depending	O
on	O
the	O
resolution	O
used	O
the	O
system	O
may	O
use	O
less	O
.	O
</s>
<s>
Sometimes	O
more	O
than	O
one	O
mode	O
was	O
possible	O
:	O
The	O
number	O
of	O
horizontal	O
and	O
Vertical	O
pixels	O
the	O
system	O
could	O
display	O
in	O
a	O
high	B-Algorithm
resolution	I-Algorithm
mode	O
and	O
The	O
number	O
of	O
colors	O
each	O
pixel	O
could	O
have	O
in	O
High-resolution	O
mode	O
,	O
where	O
several	O
high-resolution	O
modes	O
exist	O
each	O
one	O
is	O
listed	O
separately	O
.	O
</s>
<s>
Beginning	O
with	O
the	O
Xerox	B-Device
Alto	I-Device
,	O
systems	O
forwent	O
independent	O
text	B-Application
modes	I-Application
and	O
drew	O
text	O
on	O
a	O
high-resolution	O
graphics	O
screen	O
.	O
</s>
<s>
This	O
required	O
more	O
video	O
RAM	B-Architecture
,	O
but	O
also	O
freed	O
computer	O
fonts	O
from	O
a	O
fixed	O
grid	O
.	O
</s>
<s>
LC	O
Some	O
systems	O
could	O
only	O
display	O
upper	O
case	O
characters	O
in	O
text	B-Application
mode	I-Application
because	O
of	O
their	O
limited	O
character	O
set	O
,	O
If	O
a	O
system	O
was	O
able	O
to	O
also	O
support	O
lower	O
case	O
letters	O
in	O
a	O
text	B-Application
mode	I-Application
,	O
(	O
in	O
any	O
high-resolution	O
mode	O
it	O
is	O
of	O
course	O
always	O
possible	O
)	O
,	O
then	O
there	O
is	O
LC	O
(	O
for	O
Lower	O
Case	O
)	O
in	O
this	O
column	O
.	O
</s>
<s>
BG	O
Some	O
systems	O
used	O
a	B-Data_Structure
matrix	I-Data_Structure
of	I-Data_Structure
blocky	I-Data_Structure
pixels	I-Data_Structure
instead	I-Data_Structure
of	I-Data_Structure
a	I-Data_Structure
letter	I-Data_Structure
in	O
their	O
font	O
sets	O
(	O
or	O
used	O
dedicated	O
hardware	O
to	O
emulate	O
them	O
,	O
like	O
the	O
TRS-80	B-Device
did	O
)	O
,	O
to	O
support	O
some	O
sort	O
of	O
all	O
points	O
addressable	O
(	O
APA	O
)	O
mode	O
.	O
</s>
<s>
It	O
's	O
hard	O
to	O
call	O
this	O
a	O
"	O
high	B-Algorithm
resolution	I-Algorithm
"	O
mode	O
because	O
the	O
resolution	O
could	O
be	O
as	O
low	O
as	O
80×48	O
pixels	O
,	O
but	O
in	O
any	O
case	O
,	O
it	O
was	O
possible	O
to	O
draw	O
pictures	O
with	O
them	O
.	O
</s>
<s>
Many	O
systems	O
like	O
the	O
PET	B-Device
had	O
a	O
few	O
of	O
such	O
characters	O
dedicated	O
to	O
blocking	O
graphics	O
for	O
an	O
APA	O
mode	O
as	O
well	O
,	O
often	O
only	O
for	O
2×2	O
matrix	O
characters	O
.	O
</s>
<s>
Soft	O
font	O
When	O
the	O
system	O
had	O
a	O
programmable	O
font	O
RAM	B-Architecture
instead	O
of	O
a	O
static	O
"	O
font	O
ROM	B-Device
"	O
,	O
or	O
when	O
the	O
video	O
system	O
did	O
not	O
have	O
a	O
hardware	B-Application
text	I-Application
mode	I-Application
,	O
but	O
painted	O
text	O
in	O
the	O
high-res	O
screen	O
using	O
software	O
,	O
the	O
video	O
display	O
was	O
n't	O
dependent	O
on	O
a	O
permanent	O
font	O
set	O
,	O
in	O
this	O
case	O
we	O
are	O
talking	O
about	O
a	O
system	O
with	O
a	O
"	O
soft	O
"	O
font	O
.	O
</s>
<s>
Color	O
resolution	O
in	O
"	O
high-resolution	O
mode	O
"	O
it	O
was	O
often	O
the	O
case	O
that	O
a	O
certain	O
pixel	O
could	O
not	O
be	O
given	O
an	O
arbitrary	O
color	O
,	O
often	O
certain	O
clusters	O
of	O
pixels	O
,	O
(	O
quite	O
often	O
8×8	O
pixels	O
large	O
)	O
shared	O
the	O
same	O
"	O
color	O
attribute	O
"	O
,	O
so	O
as	O
to	O
spare	O
video	O
memory	O
,	O
as	O
an	O
8-bit	O
computer	O
only	O
had	O
a	O
64	O
KB	O
address	O
space	O
,	O
and	O
the	O
CPU	B-Device
often	O
had	O
limited	O
capabilities	O
to	O
manipulate	O
video	O
memory	O
,	O
therefore	O
it	O
was	O
often	O
necessary	O
to	O
keep	O
the	O
video	O
RAM	B-Architecture
size	O
as	O
small	O
as	O
possible	O
,	O
so	O
a	O
minimum	O
of	O
the	O
address	O
space	O
of	O
the	O
micro	O
was	O
used	O
,	O
and	O
also	O
the	O
video	O
content	O
could	O
be	O
changed	O
relatively	O
rapidly	O
.	O
</s>
<s>
Palette	B-Data_Structure
support	O
If	O
the	O
system	O
could	O
translate	O
a	O
"	O
logical	O
color	O
"	O
into	O
a	O
(	O
larger	O
number	O
)	O
or	O
true	O
colors	O
using	O
a	O
palette	B-Data_Structure
mechanism	I-Data_Structure
then	O
this	O
column	O
lists	O
the	O
number	O
of	O
logical	O
colors	O
the	O
palette	B-Data_Structure
could	O
accept	O
,	O
and	O
the	O
number	O
of	O
colors	O
it	O
could	O
translate	B-Data_Structure
to	I-Data_Structure
.	O
</s>
<s>
HW	O
accel	O
Short	O
for	O
"	O
hardware	B-General_Concept
acceleration	I-General_Concept
"	O
,	O
can	O
take	O
several	O
forms	O
,	O
the	O
most	O
obvious	O
form	O
is	O
"	O
bit	O
blitting	B-Algorithm
"	O
,	O
that	O
is	O
the	O
moving	O
of	O
groups	O
of	O
pixels	O
from	O
one	O
place	O
in	O
video	O
memory	O
to	O
another	O
without	O
the	O
CPU	B-Device
doing	O
any	O
of	O
the	O
moving	O
,	O
another	O
often-used	O
technique	O
is	O
hardware	O
scrolling	O
which	O
in	O
fact	O
emulates	O
moving	O
the	O
whole	O
screen	O
in	O
the	O
video	O
RAM	B-Architecture
,	O
the	O
third	O
form	O
of	O
hardware	B-General_Concept
acceleration	I-General_Concept
is	O
the	O
use	O
of	O
sprites	O
implemented	O
in	O
hardware	O
.	O
</s>
<s>
Some	O
systems	O
also	O
supported	O
drawing	O
lines	O
(	O
and	O
sometimes	O
rectangles	O
)	O
using	O
special	O
line	B-Algorithm
drawing	I-Algorithm
hardware	O
.	O
</s>
<s>
SP	O
For	O
the	O
fourth	O
facet	O
,	O
is	O
the	O
number	O
of	O
sprites	O
per	O
scan	B-Algorithm
line	I-Algorithm
.	O
</s>
<s>
Availability	O
of	O
hardware	O
to	O
do	O
this	O
limits	O
the	O
number	O
of	O
sprites	O
that	O
can	O
be	O
displayed	O
on	O
each	O
scan	B-Algorithm
line	I-Algorithm
.	O
</s>
<s>
This	O
number	O
tells	O
how	O
many	O
sprites	O
could	O
be	O
displayed	O
on	O
a	O
scanline	B-Algorithm
before	O
one	O
of	O
them	O
became	O
invisible	O
because	O
of	O
hardware	O
limitations	O
.	O
</s>
<s>
This	O
is	O
so	O
because	O
the	O
video	O
data	O
was	O
stored	O
,	O
not	O
in	O
RAM	B-Architecture
,	O
but	O
in	O
six	O
Signetics	O
2504	O
"	O
Dynamic	B-General_Concept
shift	I-General_Concept
registers	I-General_Concept
"	O
which	O
each	O
held	O
1024	O
bits	O
.	O
</s>
<s>
But	O
only	O
40×24	O
=	O
960	O
locations	O
in	O
the	O
shift	B-General_Concept
register	I-General_Concept
were	O
actually	O
used.40	O
×24	O
Mono40×24	O
Monothe	O
six	O
bits	O
per	O
character	O
location	O
were	O
only	O
enough	O
to	O
address	O
64	O
characters	O
,	O
A	O
Signetics	O
2513	O
character	O
generator	O
ROM	B-Device
held	O
only	O
uppercase	O
characters	O
and	O
some	O
other	O
alphanumerical	O
characters	O
in	O
a	O
5×7	O
matrix.Datapoint	O
22001971840	O
Bytes80×12	O
Mono80×12	O
MonoLCShift	O
registers	O
for	O
RAMThe	O
Datapoint	O
used	O
shift	B-General_Concept
registers	I-General_Concept
for	O
its	O
video	O
RAM	B-Architecture
and	O
used	O
the	O
power	O
line	O
frequency	O
timing	O
(	O
50	O
or	O
60	O
cycles	O
per	O
second	O
)	O
for	O
a	O
complete	O
refresh	O
cycle	O
.	O
</s>
<s>
When	O
writing	O
to	O
the	O
Display	O
the	O
CPU	B-Device
had	O
to	O
wait	O
for	O
the	O
next	O
"	O
window	O
"	O
,	O
which	O
came	O
50	O
(	O
or	O
60	O
)	O
times	O
a	O
second	O
.	O
</s>
<s>
Then	O
the	O
CPU	B-Device
could	O
write	O
a	O
single	O
character	O
,	O
or	O
(	O
with	O
special	O
software	O
)	O
multiple	O
characters	O
,	O
up	O
to	O
all	O
960.MUPID198364K2K	O
32	O
bits	O
woorden	O
per	O
karakter	O
,	O
zie40×25	O
16+16	O
colors320×240	O
16+16	O
colors320×240LC	O
,	O
BG	O
,	O
SGuser	O
generated	O
graphic	O
symbols	O
lie	O
at	O
the	O
heart	O
of	O
the	O
Mupid	B-Device
's	O
graphics	O
capabilities16	O
fixed	O
colors	O
,	O
and	O
16	O
chooseable	O
from	O
a	O
palette	B-Data_Structure
of	O
4096	O
colorsDesigned	O
by	O
academics	O
as	O
a	O
BTX	O
terminal	B-General_Concept
,	O
but	O
with	O
the	O
capabilities	O
of	O
a	O
home	O
computerTU	O
Graz	O
page	O
about	O
how	O
the	O
Mupid	B-Device
came	O
to	O
beSOL-201976	O
The	O
SOL-20	O
used	O
the	O
Motorola	O
6574	O
character	O
generator	O
ROM	B-Device
as	O
a	O
basis1K64×16	O
MonoLimited	O
512x128	O
Mono	O
with	O
MC6574(64x16 )	O
LC	O
,	O
SGthe	O
first	O
32	O
characters	O
in	O
the	O
Motorola	O
character	O
generator	O
ROM	B-Device
contained	O
special	O
pseudo	O
graphics	O
characters	O
,	O
mostly	O
line-drawing	O
characters	O
,	O
and	O
such	O
.	O
</s>
<s>
For	O
the	O
ASCII	B-Protocol
BELL	O
code	O
there	O
was	O
a	O
simple	O
bell	O
shape	O
in	O
the	O
character	O
set	O
.	O
</s>
<s>
Alternatively	O
,	O
the	O
character	O
ROM	B-Device
could	O
produce	O
two-letter	O
abbreviations	O
of	O
the	O
ASCII	B-Protocol
control	O
charactersOne	O
of	O
the	O
first	O
systems	O
with	O
built-in	O
video	O
hardwareeven	O
earlier	O
than	O
the	O
SOL-20	O
were	O
the	O
many	O
early	O
S100	B-Architecture
bus	I-Architecture
based	O
systems	O
one	O
could	O
also	O
insert	O
a	O
video	O
card	O
into	O
,	O
some	O
were	O
very	O
primitive	O
but	O
many	O
had	O
very	O
good	O
graphics	O
capabilities	O
,	O
one	O
such	O
an	O
S100	O
based	O
system	O
was	O
the	O
ECD	O
Corporation	O
's	O
Micro	O
Mini	O
.	O
</s>
<s>
Perhaps	O
the	O
most	O
famous	O
one	O
(	O
at	O
the	O
time	O
)	O
was	O
the	O
Cromemco	B-Device
Dazzler	I-Device
.	O
</s>
<s>
Semi	O
:	O
64×48Using	O
2×3	O
text	B-Data_Structure
semigraphics	I-Data_Structure
characters	O
,	O
like	O
the	O
TRS-80	B-Device
on	O
an	O
8×13	O
pixels	O
per	O
character	O
matrix	O
this	O
means	O
that	O
one	O
of	O
the	O
rows	O
was	O
4	O
pixels	O
high	O
instead	O
of	O
3	O
note	O
that	O
the	O
pixels	O
were	O
separated	O
by	O
a	O
1-pixel	O
wide	O
barrier	O
,	O
this	O
was	O
necessary	O
because	O
the	O
bottom	O
(	O
last	O
)	O
row	O
of	O
pixels	O
of	O
any	O
character	O
had	O
to	O
be	O
black	O
,	O
as	O
it	O
was	O
this	O
row	O
that	O
was	O
used	O
during	O
times	O
when	O
not	O
displaying	O
the	O
visible	O
area	O
of	O
the	O
screen	O
.	O
</s>
<s>
Like	O
the	O
ZX81	O
it	O
was	O
software-driven.due	O
to	O
a	O
special	O
software	O
trick	O
the	O
Galaksija	B-Device
could	O
do	O
smooth	O
scrollingOSI	O
Superboard	B-Application
II	I-Application
,	O
The	O
OSI	O
Superboard	B-Application
II	I-Application
was	O
also	O
famous	O
for	O
being	O
the	O
first	O
system	O
for	O
which	O
Microsoft	B-Language
BASIC	I-Language
in	O
ROM	B-Device
was	O
available	O
Compukit	B-Device
UK101Virtual	O
clone	O
of	O
Ohio	B-Application
Scientific	I-Application
Superboard	B-Application
II	I-Application
computer	O
with	O
an	O
improved	O
text	B-Application
mode	I-Application
,	O
as	O
the	O
original	O
used	O
a	O
less	O
useful	O
32×32	O
text	B-Application
mode	I-Application
and	O
clones19791K1.5K	O
with	O
color	O
RAM	B-Architecture
slot	O
populated32×32Presumably	O
the	O
Compukit	B-Device
UK101	I-Device
could	O
access	O
this	O
mode	O
or	O
64x16alternating	O
used	O
and	O
unused	O
lines	O
of	O
a	O
64x32	O
matrixselectable	O
by	O
a	O
poke	O
to	O
the	O
keyboard	O
registeractually	O
only	O
an	O
area	O
of	O
24×24	O
or	O
48x15	O
(	O
alternating	O
used	O
and	O
unused	O
lines	O
of	O
a	O
48x30	O
matrix	O
)	O
visible	O
,	O
the	O
area	O
outside	O
that	O
was	O
n't	O
normally	O
visible	O
on	O
a	O
TV	O
,	O
and	O
therefore	O
not	O
used	O
by	O
the	O
software	O
.	O
</s>
<s>
Semi	O
:	O
64×48Using	O
the	O
eight	O
text	B-Data_Structure
semigraphics	I-Data_Structure
characters	O
,	O
plus	O
the	O
"	O
inverse	O
video	O
"	O
option	O
,	O
it	O
was	O
possible	O
to	O
display	O
a	O
very	O
coarse	O
64×48	O
point	O
addressable	O
mode	O
Mono(32x24 )	O
BG	O
,	O
SG	O
"	O
slow	O
mode	O
"	O
,	O
software-generated	O
displayslow	O
mode	O
meant	O
that	O
BASIC	O
programs	O
only	O
could	O
generate	O
a	O
display	O
or	O
do	O
computing	O
work	O
,	O
not	O
both	O
at	O
the	O
same	O
time	O
while	O
displaying	O
a	O
picture	O
the	O
only	O
other	O
task	O
the	O
ZX80	B-Operating_System
did	O
was	O
waiting	O
for	O
a	O
key-press	O
.	O
</s>
<s>
System	O
name	O
YearChip	O
nameVideo	O
RAMVideo	O
mode(s )	O
color	O
resolutionFont	O
extrassoft	O
fontspalette	O
supportHW	O
accelunique	O
featuresTextGraphics	O
ABC80	B-Device
1978	O
1K	O
40×24	O
MonoSemi	O
:	O
78×72Using	O
2×3	O
Videotex	B-Operating_System
block	O
graphics	O
(	O
text	B-Data_Structure
semigraphics	I-Data_Structure
)	O
Mono(39x24 )	O
LC	O
,	O
BG	O
-	O
One	O
of	O
the	O
first	O
systems	O
with	O
serial	O
attributes	O
like	O
Ceefax	O
and	O
Prestel	B-General_Concept
systems	O
,	O
needed	O
the	O
first	O
character	O
of	O
a	O
line	O
for	O
switching	O
to	O
graphics	O
mode	O
,	O
thus	O
the	O
horizontal	O
resolution	O
is	O
78	O
,	O
not	O
80Somewhat	O
like	O
the	O
Sinclair	B-Operating_System
Spectrum	I-Operating_System
with	O
its	O
"	O
parallel	O
attributes	O
"	O
the	O
serial	O
attributes	O
of	O
the	O
Oric	B-Device
could	O
,	O
using	O
an	O
amount	O
of	O
video	O
memory	O
that	O
was	O
just	O
big	O
enough	O
for	O
a	O
monochrome	O
display	O
,	O
create	O
a	O
color	O
display	O
with	O
many	O
extra	O
features	O
.	O
</s>
<s>
In	O
Oric	B-Device
's	O
case	O
they	O
were	O
double-height	O
characters	O
,	O
blinking	O
characters	O
,	O
switching	O
between	O
text	O
and	O
high-res	O
graphics	O
on	O
the	O
screen	O
,	O
switching	O
between	O
character	O
sets	O
,	O
(	O
from	O
character	O
ROM	B-Device
,	O
or	O
programmable	O
character	O
sets	O
)	O
switching	O
the	O
eight	O
fore	O
-	O
and	O
background	O
colors	O
,	O
and	O
more	O
.	O
</s>
<s>
Reference	O
see	O
:	O
Apple	O
IIAnd	O
the	O
plethora	O
of	O
its	O
clones	O
,	O
see	O
List	B-Device
of	I-Device
Apple	I-Device
II	I-Device
clones	I-Device
1977	O
18KThe	O
Apple	B-Device
II	I-Device
has	O
a	O
1K	O
text	O
buffer	O
for	O
the	O
40×24	O
text	B-Application
mode	I-Application
or	O
the	O
40×48	O
low-resolution	O
graphics	O
mode	O
,	O
and	O
an	O
8K	O
frame	B-Algorithm
buffer	I-Algorithm
for	O
the	O
280×192	O
High-resolution	O
graphics	O
mode	O
.	O
</s>
<s>
The	O
first	O
high-resolution	O
frame	B-Algorithm
buffer	I-Algorithm
runs	O
from	O
2000H	O
to	O
3FFFH	O
and	O
the	O
second	O
one	O
from	O
4000H	O
to	O
5FFFH	O
.	O
</s>
<s>
All	O
this	O
is	O
true	O
for	O
all	O
seven	O
pixels	O
of	O
a	O
display	O
byte	O
where	O
its	O
eighth	O
bit	O
would	O
be	O
0	O
(	O
off	O
)	O
,	O
if	O
this	O
bit	O
was	O
turned	O
"	O
on	O
"	O
(	O
to	O
1	O
)	O
,	O
then	O
the	O
violet	O
and	O
green	O
would	O
be	O
exchanged	O
by	O
blue	O
and	O
orange	O
,	O
except	O
in	O
revision	O
0	O
board	O
,	O
which	O
could	O
only	O
display	O
4	O
colors	O
,	O
black	O
,	O
white	O
,	O
green	O
and	O
violet	O
,	O
because	O
the	O
eighth	O
bit	O
of	O
the	O
display	O
byte	O
had	O
no	O
effect	O
Full	O
:	O
280×192The	O
Apple	O
only	O
displayed	O
7	O
pixels	O
of	O
each	O
byte	O
of	O
the	O
frame	B-Algorithm
buffer	I-Algorithm
,	O
the	O
eighth	O
one	O
was	O
used	O
to	O
determine	O
which	O
color	O
combinations	O
the	O
pixels	O
of	O
the	O
other	O
seven	O
bits	O
could	O
have	O
Mono/6	O
colors	O
Semi	O
:	O
40×48exchanging	O
the	O
character	O
set	O
for	O
blocks	O
of	O
1x2	O
pixels	O
15	O
colorseach	O
byte	O
of	O
text-mode	B-Application
RAM	B-Architecture
was	O
divided	O
in	O
two	O
nibbles	O
.	O
</s>
<s>
The	O
sixteen	O
available	O
bit	O
combinations	O
produced	O
fifteen	O
unique	O
colors	O
as	O
the	O
two	O
grays	O
were	O
identical	O
in	O
shade	O
;	O
the	O
colors	O
were	O
,	O
according	O
to	O
the	O
official	O
documentation	O
:	O
black	O
,	O
magenta	O
,	O
dark	O
blue	O
,	O
purple	O
,	O
dark	O
green	O
,	O
grey	O
1	O
,	O
medium	O
blue	O
,	O
light	O
blue	O
,	O
brown	O
,	O
orange	O
,	O
grey	O
2	O
,	O
pink	O
,	O
light	O
green	O
,	O
yellow	O
,	O
aquamarine	O
,	O
white	O
40x48	O
,	O
140×192half	O
the	O
pixel	O
resolution	O
Characters	O
could	O
also	O
be	O
inverted	O
or	O
blinking	O
,	O
The	O
arrangement	O
was	O
not	O
completely	O
ASCII	B-Protocol
compatible	O
!	O
</s>
<s>
Semi	O
:	O
80×50	O
using	O
part	O
of	O
its	O
pseudo	O
graphic	O
characters	O
set	O
(	O
80x50	O
,	O
40x200	O
)	O
BG	O
,	O
SG	O
-	O
Original	O
computer	O
with	O
non	O
ASCII	B-Protocol
(	O
PETSCII	B-Protocol
)	O
character	O
set.Exidy	O
Sorcerer	O
1978	O
1920	O
Bytes	O
64×30	O
Mono	O
"	O
Full	O
"	O
:	O
Limited	O
512×240With	O
clever	O
programming	O
the	O
actual	O
resolution	O
of	O
the	O
screen	O
of	O
512×240	O
could	O
be	O
put	O
to	O
good	O
use	O
.	O
</s>
<s>
Per	O
default	O
,	O
the	O
firmware	O
filled	O
the	O
programmable	O
character	O
set	O
with	O
pseudo	O
graphics	O
symbols	O
like	O
the	O
PET	B-Device
,	O
and	O
the	O
Superboard	B-Application
II	I-Application
and	I-Application
UK101	I-Application
,	O
which	O
could	O
be	O
used	O
to	O
build	O
larger	O
simple	O
graphical	O
figures	O
,	O
like	O
a	O
"	O
Stick	O
figure	O
"	O
.	O
</s>
<s>
Semi	O
:	O
128x90Limited	O
"	O
graphics	O
"	O
modes	O
were	O
possible	O
by	O
programming	O
the	O
128	O
(	O
8×8	O
pixel	O
)	O
programmable	O
characters	O
,	O
one	O
way	O
is	O
to	O
dedicate	O
64	O
of	O
them	O
to	O
program	O
2×3	O
pseudo	O
graphics	O
characters	O
(	O
text	B-Data_Structure
semigraphics	I-Data_Structure
like	O
the	O
TRS-80	B-Device
)	O
which	O
would	O
make	O
a	O
128×90	O
"	O
pseudo	O
graphics	O
"	O
mode	O
possible	O
.	O
</s>
<s>
Semi	O
:	O
64x75/90	O
,	O
80x75/90	O
,	O
128x75/90	O
,	O
160x75/90derived	O
from	O
Videotext	O
mode	O
feature	O
Mono( 	O
64x75/90	O
,	O
80x75/90	O
,	O
128x75/90	O
,	O
160x75/90	O
;	O
256	O
,	O
320	O
,	O
512	O
,	O
640x256	O
)	O
LC	O
,	O
BG	O
-	O
Built	O
in	O
one	O
line	O
VFD	O
,	O
Videotext	O
mode	O
support	O
Interact	B-Device
Home	I-Device
Computer	I-Device
1979	O
2184	O
Bytes	O
17×12	O
4	O
colors	O
Semi	O
:	O
112×78	O
4	O
colors112×78Characters	O
were	O
drawn	O
on	O
a	O
112×78	O
pixel	O
graphics	O
screen	O
which	O
means	O
that	O
each	O
character	O
was	O
6×6	O
pixels	O
,	O
including	O
blank	O
space	O
between	O
the	O
characters	O
,	O
which	O
led	O
to	O
very	O
blocky	O
characters	O
,	O
which	O
simply	O
did	O
n't	O
allow	O
for	O
distinct	O
lower	O
case	O
characters.In	O
theory	O
,	O
the	O
"	O
graphics	O
"	O
screen	O
text	O
was	O
drawn	O
on	O
could	O
be	O
the	O
text-mode	B-Application
semigraphics	B-Data_Structure
screen	O
for	O
a	O
more	O
standard	O
(	O
for	O
the	O
time	O
)	O
56x26	O
or	O
56x39	O
high-resolution	O
text	B-Application
mode	I-Application
,	O
though	O
in	O
practice	O
this	O
real	O
text	B-Application
mode	I-Application
was	O
apparently	O
never	O
used	O
(	O
if	O
it	O
even	O
could	O
be	O
)	O
.	O
</s>
<s>
4	O
of	O
8	O
Kaypro	O
II	O
series	O
1982	O
2	O
KB	O
80×24	O
Mono	O
,	O
on	O
9	O
"	O
built	O
in	O
CRT	O
Semi	O
:	O
Presumably	O
160x72	O
Mono	O
(	O
80x24	B-Application
)	O
LC	O
,	O
BG1984	O
model	O
No	O
-	O
NASCOM	B-Operating_System
1	I-Operating_System
NASCOM	B-Operating_System
2	O
1977	O
1979	O
1K	O
48×16	O
Mono	O
N/A	O
LC	O
No	O
None	O
Osborne	B-Device
1	I-Device
,	O
</s>
<s>
Osborne	B-Device
Executive	I-Device
and	O
Osborne	O
Vixen1981	O
,	O
1982	O
,	O
19844Kfor	O
128x32	O
display	O
memory52x24	O
Mono	O
on	O
5	O
"	O
CRT	O
,	O
later	O
80x24	B-Application
on	O
7	O
"	O
CRT	O
"	O
Full	O
"	O
:	O
Presumably	O
limited	O
416x192	O
Mono	O
,	O
later	O
limited	O
640x192	O
using	O
its	O
pseudo	O
graphic	O
characters	O
setWindow	O
on	O
display	B-Algorithm
memory	I-Algorithm
(	O
52x24	O
,	O
later	O
80x24	B-Application
)	O
LC	O
,	O
SGUses	O
virtual	O
screen	O
to	O
make	O
up	O
for	O
limitations	O
of	O
original	O
5	O
"	O
CRT	O
,	O
a	O
feature	O
presumably	O
not	O
dropped	O
from	O
later	O
models	O
in	O
order	O
to	O
achieve	O
full	O
backward	B-General_Concept
compatibility	I-General_Concept
Panasonic	B-Device
JR-200	I-Device
1983	O
2K+2K2K	O
VRAM	O
+	O
2K	O
Character	O
RAM	B-Architecture
according	O
to	O
old-computers.com	O
.	O
</s>
<s>
Semi	O
:	O
64×4864×48	O
by	O
using	O
one	O
of	O
the	O
16	O
available	O
characters	O
with	O
a	O
4×4	O
pixel	O
(	O
quarter	O
character	O
)	O
text	B-Data_Structure
semigraphics	I-Data_Structure
pattern	O
8	O
colors32x24	O
LC	O
,	O
BG	O
unique	O
semi-graphic	O
pixel	O
color	O
attribute	O
scheme	O
made	O
that	O
each	O
of	O
the	O
64×48	O
semi-graphic	O
"	O
pixels	O
"	O
(	O
consisting	O
of	O
a	O
quarter	O
of	O
an	O
8×8	O
pixel	O
character	O
space	O
)	O
could	O
have	O
its	O
own	O
independent	O
color	O
,	O
these	O
semi-graphics	O
could	O
be	O
combined	O
with	O
predefined	O
characters	O
,	O
or	O
programmable	O
characters	O
,	O
each	O
of	O
which	O
could	O
also	O
have	O
an	O
independent	O
foreground	O
and	O
background	O
color	O
out	O
of	O
a	O
palette	B-Data_Structure
of	O
8	O
.	O
</s>
<s>
87.x1	O
:	O
960+960Only	O
seven	O
bits	O
of	O
each	O
byte	O
are	O
defined	O
bytes85/1	O
,	O
87	O
:	O
40x20	O
Mono	O
for	O
85/1	O
,	O
87.x0	O
;	O
16	O
foreground	O
colors	O
+	O
8	O
background	O
colors	O
for	O
87.x185/1	O
,	O
87	O
:	O
Limited	O
320x192	O
Mono	O
for	O
85/1	O
,	O
87.x0	O
;	O
16	O
foreground	O
colors	O
+	O
8	O
background	O
colors	O
for	O
87.x1	O
using	O
its	O
pseudo	O
graphic	O
characters	O
set87.x1	O
:	O
40x24LCThe	O
85/1	O
and	O
87	O
also	O
offer	O
semigraphics	B-Data_Structure
,	O
but	O
this	O
mode	O
uses	O
a	O
higher	O
40x24	O
resolution	O
TRS-80	B-Device
Models	O
I	O
and	O
IIISome	O
of	O
its	O
many	B-Device
clones	I-Device
used	O
CRTCs	O
1977	O
,	O
1980	O
up	O
to	O
1KActually	O
there	O
were	O
only	O
seven	O
1024×1	O
bit	O
RAMs	B-Architecture
used	O
in	O
the	O
Model	O
I	O
to	O
store	O
the	O
seven	O
bits	O
per	O
character	O
,	O
but	O
there	O
was	O
an	O
unpopulated	O
socket	O
for	O
an	O
eighth	O
RAM	B-Architecture
.	O
</s>
<s>
Of	O
the	O
128	O
possible	O
characters	O
64	O
were	O
used	O
for	O
the	O
"	O
pseudographics	B-Data_Structure
"	O
,	O
and	O
the	O
remaining	O
64	O
came	O
from	O
a	O
character	O
generator	O
PROM	O
that	O
only	O
contained	O
uppercase	O
characters	O
32×16	O
or	O
64×16	O
Mono	O
Semi	O
:	O
64×48	O
or	O
128×48	O
Mono(32x16 or 64x16 )	O
LC	O
,	O
actually	O
exists	O
in	O
the	O
Model	O
I	O
character	O
set	O
,	O
but	O
Model	O
I	O
needs	O
an	O
eighth	O
chip	O
(	O
which	O
BASIC	O
needs	O
to	O
be	O
disabled	O
)	O
to	O
display	O
it	O
BG	O
No	O
None	O
The	O
canonical	O
system	O
to	O
use	O
Text	O
semigraphicseach	O
character	O
mapped	O
to	O
a	O
matrix	O
of	O
2×3	O
pixels	O
to	O
generate	O
a	O
"	O
semi-high	O
resolution	O
mode	O
"	O
.	O
</s>
<s>
No	O
Video	O
RAM	B-Architecture
arbitration	O
logic	O
meant	O
that	O
writing	O
to	O
the	O
screen	O
caused	O
a	O
lot	O
of	O
"	O
black	O
snow	O
"	O
,	O
that	O
is	O
black	O
stripes	O
in	O
the	O
screen	O
during	O
write	O
accesses	O
.	O
</s>
<s>
+System	O
nameYearChip	O
nameVideo	O
RAMVideo	O
mode(s )	O
color	O
resolutionFont	O
extrassoft	O
fontspalette	O
supportunique	O
featuresApple	O
III198064K40×24	O
Text	O
in	O
280×192	O
Graphics	O
or	O
80×24	O
in	O
560×192In	O
theory	O
it	O
was	O
possible	O
to	O
draw	O
block	O
graphics	O
on	O
the	O
real	O
high-resolution	O
screen	O
,	O
but	O
it	O
was	O
mostly	O
pointless	O
to	O
do	O
this	O
in	O
practice	O
2	O
or	O
16	O
colors16	O
colors	O
or	O
shades	O
of	O
green140x192	O
,	O
280x192	O
;	O
140x192	O
,	O
560x192LC228	O
programmable	O
characters	O
,	O
bundled	O
with	O
Apple	B-Device
II	I-Device
software	O
emulatorApple	O
Lisa/Macintosh	O
XL1983Presumably	O
2x32760	O
bytesdrawn	O
by	O
software	O
on	O
720x364r/608x432s	O
mono	O
,	O
(	O
4	O
gray	O
scales	O
)	O
(	O
720x364r/608x432s	O
)	O
YesApple	O
Macintosh	B-Device
128K	I-Device
and	O
other	O
compact	O
models1984	O
-The	O
framebuffer	B-Algorithm
was	O
built	O
out	O
of	O
discrete	O
logic	O
,	O
but	O
a	O
PAL	O
generated	O
the	O
video	O
timing	O
signals2x21888	O
bytesdrawn	O
by	O
software	O
on	O
512x342	O
mono	O
,	O
(	O
4	O
grayscales	O
)	O
(	O
512x342	O
)	O
SE/30	O
and	O
Classic	O
were	O
the	O
only	O
32-bit	O
models	O
to	O
use	O
discrete	O
logic	O
to	O
implement	O
video	O
hardwareDAI	O
Personal	O
Computer1979	O
-basically	O
the	O
VDU	O
was	O
built	O
using	O
discrete	O
logic	O
,	O
but	O
a	O
Ferranti	O
ZNA134	O
was	O
used	O
to	O
generate	O
the	O
video	O
timing	O
pulses31680	O
bytesDepending	O
on	O
the	O
resolution	O
715/1430	O
bytes	O
,	O
2860/5720	O
bytes	O
,	O
11440/22880	O
bytes	O
or	O
15840/31680	O
bytes	O
of	O
RAM	B-Architecture
was	O
used88×65	O
,	O
176×130	O
,	O
blocky	O
versions	O
of	O
the	O
high	B-Algorithm
resolution	I-Algorithm
graphics	O
mode	O
352×260	O
,	O
60x24The	O
ZNA134	O
actually	O
generated	O
the	O
correct	O
video	O
timing	O
pulses	O
for	O
lines	O
of	O
66	O
characters	O
but	O
the	O
VDU	O
generally	O
would	O
not	O
display	O
these	O
extra	O
columns	O
in	O
text	B-Application
mode	I-Application
Text	O
in	O
528×240	O
Graphics	O
4	O
or	O
16	O
colors88×65	O
,	O
176×130	O
,	O
352×260	O
,	O
528×240LC	O
-4	O
of	O
16In	O
4	O
color	O
mode	O
the	O
logical	O
palette	B-Data_Structure
per	O
line	O
was	O
limited	O
to	O
one	O
foreground	O
and	O
one	O
background	O
color	O
,	O
and	O
in	O
16	O
color	O
mode	O
it	O
was	O
limited	O
to	O
four	O
.	O
</s>
<s>
In	O
either	O
mode	O
only	O
one	O
palette	B-Data_Structure
color	I-Data_Structure
was	O
allowed	O
to	O
be	O
changed	O
at	O
a	O
time.split	O
screen	O
text	O
and	O
graphics	O
mode	O
with	O
4-line	O
captionPMD	O
8519859600	O
BytesCalculated	O
as	O
288×256	O
pixels/8	O
=	O
9216	O
bytes	O
for	O
pixel	O
data	O
and	O
384	O
bytes	O
for	O
grayscale	O
data	O
(	O
2	O
bits	O
per	O
pixel	O
)	O
for	O
each	O
of	O
the	O
48	O
(	O
6-pixel	O
)	O
rows	O
per	O
line48×32assuming	O
6×8	O
pixels	O
per	O
character	O
,	O
details	O
are	O
unclear	O
Text	O
in	O
288×256	O
Graphics	O
4	O
gray-scales	O
,	O
4	O
colors	O
for	O
85/3288x256LCsoft	O
fonts	O
as	O
characters	O
are	O
drawn	O
only	O
in	O
a	O
graphics	O
mode	O
screen	O
,	O
no	O
text	B-Application
mode	I-Application
hardware	O
exists4	O
out	O
of	O
?	O
</s>
<s>
System	O
name	O
Year	O
Chip	O
name	O
Video	O
RAM	B-Architecture
Video	O
mode(s )	O
color	O
resolution	O
Font	O
extras	O
soft	O
fonts	O
palette	B-Data_Structure
support	O
HW	O
accelunique	O
featuresTextGraphicsApple	O
IIe	B-Device
,	O
The	O
Apple	B-Device
IIe	I-Device
used	O
two	O
ASICs	O
(	O
the	O
MMU	O
and	O
IOU	O
)	O
to	O
replace	O
most	O
of	O
the	O
discrete	O
logic	O
of	O
the	O
Apple	B-Device
II	I-Device
.	O
</s>
<s>
All	O
comments	O
for	O
the	O
Apple	B-Device
II	I-Device
apply	O
to	O
the	O
IIe	B-Device
,	O
but	O
the	O
IIe	B-Device
has	O
additional	O
capabilities	O
.	O
</s>
<s>
Apple	O
IIcAnd	O
Apple	O
IIc	O
Plus	O
,	O
which	O
has	O
identical	O
graphics	O
capabilitieshas	O
all	O
the	O
capabilities	O
of	O
the	O
Apple	B-Device
IIe	I-Device
,	O
and	O
an	O
improved	O
character	O
set1983	O
,	O
1984MMU/IOUMost	O
of	O
the	O
discrete	O
logic	O
of	O
earlier	O
Apple	B-Device
IIs	I-Device
has	O
reimplemented	O
in	O
two	O
ASICs	O
:	O
a	O
memory-management	O
unit	O
(	O
MMU	O
)	O
and	O
an	O
input/output	O
unit	O
(	O
IOU	O
)	O
.	O
</s>
<s>
These	O
chips	O
were	O
also	O
used	O
in	O
the	O
IIc.27KThe	O
Apple	B-Device
IIe	I-Device
used	O
1K	O
of	O
auxiliary-slot	O
RAM	B-Architecture
for	O
the	O
80-column	O
text	B-Application
mode	I-Application
and	O
8K	O
of	O
auxiliary-slot	O
RAM	B-Architecture
for	O
Double	O
Hi-Res	O
.	O
</s>
<s>
A	O
64K	O
expansion	O
(	O
the	O
"	O
Extended	O
80-Column	O
Card	O
"	O
)	O
was	O
most	O
commonly	O
installed	O
,	O
though	O
Apple	O
also	O
briefly	O
offered	O
a	O
1K	O
card	O
that	O
only	O
enabled	O
80-column	O
text.40	O
×24	O
or	O
80×24	O
MonoFull	O
:	O
280×192	O
6effectively	O
the	O
color	O
resolution	O
was	O
only	O
140×192	O
,	O
due	O
to	O
pixel	O
placement	O
restriction	O
or	O
15	O
Colors	O
or	O
560×192	O
15	O
colorsusing	O
the	O
"	O
resolution	O
doubler	O
"	O
originally	O
developed	O
for	O
the	O
double	O
low	O
resolution	O
mode	O
uses	O
the	O
second	O
bank	O
of	O
high	B-Algorithm
resolution	I-Algorithm
RAM	B-Architecture
.	O
</s>
<s>
Semi	O
:	O
64x32The	O
characterset	O
includes	O
8	O
(	O
one	O
set	O
for	O
each	O
color	O
)	O
×16	O
characters	O
with	O
a	O
2×2	O
pixel	O
matrix	O
,	O
with	O
this	O
a	O
mixed	O
text	O
and	O
semi	O
graphics	O
mode	O
can	O
be	O
created	O
that	O
can	O
display	O
pixels	O
in	O
8	O
colors	O
against	O
a	O
black	O
background	O
,	O
albeit	O
with	O
some	O
color	B-Algorithm
clash	I-Algorithm
9	O
colors	O
,	O
64x48Another	O
semigraphics	B-Data_Structure
mode	O
,	O
like	O
the	O
64×32	O
mode	O
,	O
but	O
exchanging	O
a	O
more	O
limited	O
number	O
of	O
colors	O
for	O
a	O
somewhat	O
higher	O
resolution	O
4	O
colors64×64	O
,	O
128×64	O
,	O
128×96	O
,	O
128×192	O
,	O
160x192-225	O
,	O
256×	O
192-225	O
,	O
320x192-225	O
,	O
512x192-225	O
or	O
640x192-225	O
;	O
64x32	O
,	O
64x48	O
BG	O
,	O
LC	O
No	O
?	O
</s>
<s>
+System	O
nameYearChip	O
nameVideo	O
RAMVideo	O
mode(s )	O
color	O
resolutionFont	O
extrassoft	O
fontspalette	O
supportHW	O
accelunique	O
featuresAtari	O
ST1985ST	O
Shifter32Kdrawn	O
by	O
software	O
16	O
colors	O
on	O
320×200	O
16	O
colors	O
,	O
640×200	O
4	O
colors	O
or	O
640×400	O
2	O
colors320x200	O
,	O
640x200LCYesYes	O
512palette	O
of	O
512	O
colorsHi-Res	O
non-interlaced	O
31	O
kHz-72	O
HzElectronika	O
BK	O
-0010/	O
-0011The	O
series	O
of	O
Soviet	O
home	O
computers	O
based	O
on	O
PDP-11	B-Device
architecture1985ULAThe	O
K1801VP1-037	O
with	O
600	O
logic	O
elements16KIt	O
was	O
one	O
of	O
the	O
biggest	O
problems	O
of	O
BK	O
,	O
which	O
was	O
n't	O
corrected	O
even	O
in	O
updated	O
-0011	O
model	O
that	O
had	O
128	O
KB	O
of	O
memory	O
,	O
as	O
16	O
KB	O
was	O
VP1-037	O
'	O
s	O
hardwired	O
limit	O
due	O
to	O
the	O
low	O
gate	O
count	O
of	O
its	O
host	O
PLA.32	O
×25	O
Text	O
in	O
256×256	O
Graphics	O
4	O
colors	O
or	O
64×25	O
in	O
512×256	O
2	O
colors256×256	O
or	O
512×	O
256YesBK-0011	O
only	O
.	O
</s>
<s>
VDC	O
lacked	O
hardware	B-Application
text	I-Application
modes	I-Application
,	O
so	O
they	O
were	O
simulated	O
in	O
software	O
by	O
BIOS	B-Operating_System
routines	O
.	O
</s>
<s>
The	O
-0011	O
model	O
had	O
an	O
updated	O
BIOS	B-Operating_System
that	O
could	O
display	O
"	O
narrow	O
"	O
symbols	O
.	O
</s>
<s>
It	O
also	O
had	O
some	O
limited	O
palette	B-Data_Structure
support.16	O
hardwired	O
4-color	O
sets	O
selectable	O
from	O
a	O
64-color	O
paletteSCBK	O
's	O
VDC	O
was	O
rather	O
primitive	O
and	O
lacked	O
most	O
advanced	O
features	O
except	O
hardware	O
scrolling	O
(	O
implemented	O
through	O
software-controlled	O
framebuffer	B-Algorithm
offset	O
register	O
)	O
.	O
</s>
<s>
However	O
,	O
the	O
fact	O
that	O
the	O
screen	O
output	O
was	O
almost	O
entirely	O
software-generated	O
,	O
together	O
with	O
powerful	O
16-bit	O
CPU	B-Device
,	O
made	O
possible	O
seamless	O
integration	O
of	O
text	O
and	O
graphics	O
with	O
escape	O
sequence-controlled	O
composite	O
output.Enterprise	O
64and	O
Enterprise	B-Operating_System
128	I-Operating_System
,	O
which	O
is	O
the	O
same	O
machine	O
,	O
only	O
with	O
more	O
memory	O
,	O
also	O
known	O
as	O
DPC	O
,	O
Samurai	O
,	O
Oscar	O
,	O
Elan	O
and	O
Flan1985Nick64KFull	O
:	O
80x256	O
256	O
colors	O
,	O
160x256	O
16	O
colors	O
,	O
40×32	O
Text	O
in	O
320x256	O
Graphics	O
4	O
colors	O
,	O
80×32	O
or	O
28	O
in	O
640x256p/	O
64	O
in	O
512i	O
2	O
colorsIn	O
"	O
LORES	O
"	O
mode	O
using	O
half	O
as	O
much	O
memory	O
,	O
the	O
horizontal	O
resolution	O
is	O
halved	O
,	O
while	O
the	O
number	O
of	O
colors	O
remain	O
the	O
same	O
.	O
</s>
<s>
These	O
figures	O
are	O
gathered	O
from	O
the	O
"	O
Enterprise	O
programming	O
guide	O
"	O
Oric	B-Device
1and	O
Oric	B-Device
Atmos	O
,	O
which	O
is	O
the	O
same	O
system	O
,	O
only	O
with	O
a	O
better	O
keyboard	O
and	O
improved	O
ROM	B-Device
.	O
</s>
<s>
Semi	O
:	O
80x84	O
8	O
colors	O
through	O
soft	O
font40×224When	O
in	O
text	B-Application
mode	I-Application
it	O
reads	O
40	O
bytes	O
in	O
memory	O
to	O
display	O
a	O
240-pixel	O
line	O
,	O
that	O
is	O
it	O
uses	O
six	O
bits	O
per	O
byte	O
,	O
six	O
bits	O
are	O
used	O
to	O
choose	O
one	O
of	O
the	O
64	O
available	O
characters	O
in	O
the	O
current	O
character	O
set	O
,	O
(	O
which	O
could	O
be	O
switched	O
)	O
the	O
other	O
two	O
bits	O
are	O
used	O
to	O
choose	O
whether	O
either	O
to	O
display	O
the	O
character	O
or	O
to	O
process	O
an	O
attribute	O
.	O
</s>
<s>
Semi	O
:	O
64x48	O
15	O
colorsEight	O
colors	O
,	O
but	O
with	O
two	O
brightness	O
levels	O
,	O
however	O
the	O
"	O
color	O
"	O
black	O
is	O
repeated	O
twice	O
(	O
it	O
was	O
the	O
same	O
with	O
each	O
brightness	O
level	O
)	O
,	O
so	O
actually	O
there	O
are	O
just	O
15	O
color	O
tints32×24LC	O
,	O
BG	O
–	O
Nonecolor	O
limitationsThe	O
Sinclair	B-Operating_System
Spectrum	I-Operating_System
high-resolution	O
screen	O
has	O
serious	O
color	O
limitations	O
.	O
</s>
<s>
This	O
is	O
because	O
of	O
the	O
separate	O
768-byte	O
color	B-Data_Structure
table	I-Data_Structure
,	O
(	O
one	O
byte	O
for	O
each	O
8×8	O
pixel	O
block	O
)	O
.	O
</s>
<s>
The	O
color	O
limitations	O
of	O
this	O
design	O
can	O
cause	O
some	O
heavy	O
attribute	B-Algorithm
clashes	I-Algorithm
,	O
for	O
which	O
the	O
Spectrum	O
is	O
indeed	O
infamous	O
.	O
</s>
<s>
Semi	O
:	O
64x48	O
15	O
colors32×24	O
,	O
32x192	O
,	O
256×192	O
,	O
512x192LC	O
,	O
BG	O
,	O
SC	O
,	O
SPyes256	O
entries	O
512	O
colors64	O
sprites	O
,	O
hardware	O
scrolling	O
,	O
copper	O
,	O
The	O
Copper	O
is	O
a	O
simple	O
programmed	O
system	O
which	O
allows	O
certain	O
Next	O
Registers	O
to	O
be	O
altered	O
automatically	O
at	O
certain	O
scanline	B-Algorithm
positions	O
.	O
</s>
<s>
Semi	O
:	O
80x75	O
16	O
colors	O
through	O
soft	O
font40×25	O
,	O
320x200Thomson	O
TO71982MC	O
13000	O
ALS	O
gate	O
array	O
on	O
TO-7/7014000	O
bytes	O
,	O
either	O
15000	O
or	O
16000	O
bytes	O
for	O
TO7/708000	O
bytes	O
for	O
pixels	O
;	O
6000	O
bytes	O
for	O
color	O
attributes	O
,	O
either	O
7000	O
or	O
8000	O
bytes	O
for	O
TO7-7040	O
×25	O
Text	O
in	O
320×200	O
Graphics	O
8	O
colors	O
,	O
16	O
for	O
TO7/7040	O
×200The	O
TO7	B-Device
used	O
a	O
complex	O
system	O
with	O
color	O
restrictions	O
,	O
Each	O
line	O
is	O
split	O
into	O
40	O
spans	O
of	O
8	O
pixels	O
and	O
each	O
span	O
can	O
only	O
have	O
two	O
different	O
colors	O
(	O
among	O
eight	O
or	O
sixteen	O
in	O
the	O
case	O
of	O
the	O
TO7-70	O
)	O
.	O
</s>
<s>
semi	O
:	O
78x75	O
8	O
or	O
2	O
colors	O
[	O
or	O
158x75	O
(	O
800M	O
,	O
802	O
,	O
806	O
)	O
]	O
256×240	O
or	O
512x240	O
(	O
806	O
)	O
,	O
40x24	O
or	O
80×24	O
(	O
802	O
,	O
806	O
)	O
LC	O
,	O
BG	O
No	O
NoneNone	O
HR	O
board	O
for	O
800	O
and	O
802	O
provides	O
16K	O
for	O
240×240	O
graphics	O
in	O
4	O
of	O
8	O
colors	O
Aster	B-Device
CT-80	I-Device
1979	O
1K	O
or	O
2KDepending	O
on	O
the	O
boot	O
floppy	O
used	O
,	O
the	O
Aster	O
reconfigured	O
its	O
internal	O
memory	O
map	O
for	O
use	O
as	O
a	O
TRS-80	B-Device
compatible	O
machine	O
or	O
a	O
fully	O
CP/M	B-Application
compatible	O
machine	O
,	O
including	O
the	O
location	O
in	O
the	O
internal	O
memory	O
map	O
of	O
the	O
video	O
memory	O
.	O
</s>
<s>
In	O
TRS-80	B-Device
mode	O
it	O
used	O
1K	O
(	O
16	O
lines	O
of	O
64	O
characters	O
)	O
and	O
used	O
all	O
8	O
bits	O
of	O
the	O
character	O
to	O
support	O
a	O
full	O
set	O
of	O
256	O
characters	O
,	O
and	O
in	O
CP/M	B-Application
compatible	O
mode	O
it	O
used	O
2000	O
bytes	O
(	O
25	O
lines	O
of	O
80	O
characters	O
)	O
of	O
a	O
dedicated	O
2K	O
memory	O
,	O
using	O
the	O
same	O
character	O
set	O
as	O
the	O
TRS-80	B-Device
mode	O
64×16	O
,	O
32×16	O
,	O
80×25	O
or	O
40×25	O
MonoSemi	O
:	O
128×48	O
,	O
64x48	O
,	O
160×75160×75	O
only	O
in	O
the	O
CP/M	B-Application
compatible	O
mode	O
or	O
80x7580x75	O
only	O
when	O
booted	O
with	O
a	O
special	O
Videotex	B-Operating_System
terminal	B-General_Concept
emulator	O
programin	O
TRS-80	B-Device
as	O
well	O
as	O
in	O
CP/M	B-Application
mode	O
the	O
Aster	O
could	O
switch	O
to	O
a	O
display	O
mode	O
where	O
it	O
would	O
only	O
display	O
the	O
odd	O
display	B-Algorithm
memory	I-Algorithm
bytes	O
at	O
double	O
width	O
.	O
</s>
<s>
The	O
40×25	O
mode	O
was	O
initiated	O
when	O
the	O
system	O
was	O
booted	O
with	O
a	O
special	O
Videotex	B-Operating_System
terminal	B-General_Concept
emulator	O
program	O
.	O
</s>
<s>
In	O
both	O
modes	O
,	O
a	O
hardware	O
"	O
de-snowing	O
"	O
(	O
Video	O
memory	O
arbitration	O
system	O
)	O
system	O
was	O
employed	O
that	O
removed	O
the	O
bothersome	O
"	O
snow	O
"	O
that	O
appeared	O
on	O
a	O
TRS-80	B-Device
screen	O
whenever	O
the	O
system	O
made	O
a	O
large	O
number	O
of	O
accesses	O
to	O
the	O
video	O
memory	O
.	O
</s>
<s>
The	O
memory	O
arbitration	O
logic	O
did	O
not	O
need	O
software	O
support	O
,	O
so	O
it	O
also	O
worked	O
with	O
all	O
existing	O
software	O
3	O
gray	O
scalesActually	O
,	O
the	O
Aster	O
could	O
display	O
the	O
TRS-80	B-Device
graphics	O
in	O
black	O
(	O
pixel	O
off	O
)	O
,	O
white	O
(	O
pixel	O
on	O
)	O
and	O
one	O
grayscale	O
halfway	O
in-between	O
black	O
and	O
white	O
,	O
which	O
was	O
accomplished	O
by	O
dithering	O
the	O
pixels	O
in	O
the	O
semi-graphics	O
block	O
with	O
a	O
checkerboard	O
pattern128×48	O
,	O
64x48	O
,	O
160×75	O
or	O
80x75	O
LC	O
,	O
BG	O
,	O
SGalthough	O
the	O
original	O
TRS-80	B-Device
Model	O
1	O
did	O
not	O
support	O
lowercase	O
the	O
Aster	O
did	O
.	O
</s>
<s>
Semi	O
:	O
160×72	O
or	O
128×48	O
Mono(80x24 or 64x16 )	O
YesPart	O
of	O
the	O
character-set	O
was	O
programmable	O
MicroBee	B-Device
1982	O
4K2K	O
"	O
screen	O
"	O
RAM	B-Architecture
,	O
2K	O
of	O
PCG	O
RAM	B-Architecture
for	O
128	O
8×16	O
charactersLater	O
models	O
up	O
to	O
56K	O
(	O
8K	O
each	O
screen	O
+	O
"	O
attribute	O
"	O
+	O
color	O
+	O
32K	O
PCG	O
64×16Later	O
models	O
also	O
80×25	O
MonoLater	O
models	O
16	O
,	O
27	O
and	O
more	O
?	O
</s>
<s>
Semi	O
:	O
Presumably	O
80x72	O
8	O
colors	O
40x24	O
,	O
256x252LCNoNoneNoneColour	O
Genie198216KColour	O
Genie	O
used	O
4080	O
bytes	O
of	O
video	O
RAM	B-Architecture
when	O
displaying	O
160×102	O
graphics	O
in	O
4	O
colors	O
and	O
could	O
use	O
"	O
page	O
flipping	O
"	O
to	O
flip	O
up	O
to	O
4	O
different	O
palettes	B-Data_Structure
of	O
4	O
colors	O
,	O
all	O
of	O
which	O
could	O
be	O
unique	O
"	O
Full	O
"	O
:	O
Limited	O
40×24or	O
40×25	O
with	O
a	O
ROM	B-Device
upgrade	O
Text	O
in	O
320×192or	O
320×200	O
with	O
a	O
ROM	B-Device
upgradeWhite	O
,	O
Red	O
,	O
Yellow	O
,	O
Orange	O
.	O
</s>
<s>
Semi	O
:	O
160x96or	O
160×102	O
with	O
upgraded	O
ROMs	O
4	O
colors	O
or	O
presumably	O
80×72or	O
80×75	O
with	O
a	O
ROM	B-Device
upgrade	O
16	O
colors40x24	O
,	O
160x96LC	O
,	O
BG	O
,	O
SGYes4	O
of	O
16Programmable	O
characters128	O
8×8	O
pixel	O
programmable	O
characters	O
,	O
plus	O
128	O
semi	O
graphic	O
characters	O
in	O
two	O
sets.Sharp	O
X1	B-Device
(	O
CZ-800C	O
)	O
198248000	O
bytesThere	O
is	O
some	O
confusion	O
here	O
,	O
according	O
to	O
some	O
sources	O
,	O
the	O
programmable	O
character	O
generator	O
(	O
PCG	O
)	O
of	O
the	O
X1	B-Device
used	O
four	O
bits	O
per	O
pixel	O
,	O
which	O
means	O
64000	O
bytes	O
of	O
RAM	B-Architecture
for	O
640x200	O
pixels	O
,	O
other	O
data	O
claims	O
only	O
48000	O
bytes	O
of	O
VRAMNot	O
accessed	O
through	O
the	O
memory	O
map	O
,	O
but	O
through	O
the	O
Z80	B-General_Concept
's	O
special	O
instructions	O
to	O
access	O
the	O
"	O
I/O	O
map	O
"	O
Turbo	O
series	O
used	O
bank	O
switching	O
to	O
store	O
pixel	O
data	O
for	O
640x400	O
resolution	O
and	O
probably	O
12-bit	O
color40×25	O
Text	O
in	O
320×200	O
Graphics	O
,	O
80×25	O
in	O
640×200It	O
is	O
not	O
obvious	O
whether	O
this	O
is	O
an	O
All	O
Points	O
Addressable	O
mode	O
,	O
or	O
that	O
these	O
are	O
in	O
fact	O
text	B-Application
modes	I-Application
that	O
used	O
the	O
Programmable	O
Character	O
Generator	O
of	O
the	O
X1	B-Device
to	O
create	O
an	O
illusion	O
that	O
High-Resolution	O
APA	O
graphics	O
were	O
possible	O
.	O
</s>
<s>
That	O
is	O
,	O
it	O
is	O
possible	O
that	O
the	O
X1	B-Device
had	O
1000	O
(	O
40×25	O
)	O
or	O
even	O
2000	O
(	O
80×25	O
)	O
or	O
even	O
more	O
unique	O
programmable	O
characters	O
so	O
that	O
there	O
could	O
be	O
one	O
PCG	O
character	O
for	O
each	O
screen	O
location	O
)	O
It	O
is	O
not	O
obvious	O
how	O
many	O
unique	O
programmable	O
characters	O
the	O
X1	B-Device
had	O
,	O
only	O
that	O
they	O
were	O
programmable	O
on	O
a	O
per-pixel	O
basis	O
with	O
3	O
or	O
4	O
bits	O
per	O
pixelTurbo	O
series	O
also	O
80x50	O
in	O
640x400	O
8	O
colors320×200	O
,	O
640×200LCyesNonenot	O
sure	O
about	O
this	O
eitherin	O
a	O
way	O
the	O
PGC	O
is	O
a	O
kind	O
of	O
sprite	O
systempowerful	O
APA	O
color	O
PCGThe	O
X1	B-Device
had	O
a	O
programmable	O
character	O
generator	O
that	O
allowed	O
per-pixel	O
programming	O
with	O
3	O
or	O
4-bit	O
per	O
pixel	O
data	O
.	O
</s>
<s>
Plus	O
the	O
fact	O
that	O
the	O
X1	B-Device
's	O
VRAM	O
was	O
not	O
memory	O
mapped	O
,	O
but	O
used	O
the	O
Z80	B-General_Concept
unique	O
extended	O
I/O	O
mapping	O
,	O
where	O
normally	O
the	O
i8080	B-General_Concept
had	O
just	O
256	O
I/O	O
locations	O
,	O
the	O
Z80	B-General_Concept
supported	O
16-bit	O
I/O	O
addressing	O
,	O
so	O
the	O
"	O
I/O	O
map	O
"	O
could	O
cover	O
64K	O
.	O
</s>
<s>
There	O
is	O
confusion	O
as	O
to	O
whether	O
the	O
X1	B-Device
used	O
48000	O
or	O
64000	O
bytes	O
of	O
the	O
I/O	O
map	O
to	O
address	O
VRAM	O
,	O
so	O
all	O
of	O
the	O
64K	O
memory	O
maps	O
could	O
be	O
RAM	B-Architecture
(	O
except	O
for	O
a	O
small	O
BIOS/IPL	O
ROM	B-Device
)	O
.Casio	O
FX-9000P19804K32	O
×16	O
Text	O
in	O
256×128	O
Graphics	O
Mono(256x128 )	O
None	O
?	O
</s>
<s>
Semi	O
:	O
128×128Most	O
probably	O
just	O
a	O
tweaked	O
semigraphics	B-Data_Structure
mode	O
dividing	O
the	O
text	O
screen	O
's	O
characters	O
into	O
a	O
2x4	O
(	O
single	O
height	O
)	O
or	O
2x8	O
(	O
double	O
height	O
)	O
semigraphics	B-Data_Structure
matrix	O
instead	O
of	O
the	O
presumed	O
2x3	O
included	O
in	O
the	O
system	O
font	O
8	O
colors	O
or	O
presumably	O
128×96	O
8	O
colors	O
or	O
128x48	O
8	O
colors	O
(	O
through	O
block	O
graphics	O
characters	O
included	O
in	O
the	O
font	O
)	O
64x16	O
or	O
64x32	O
,	O
128x128BGsaid	O
to	O
be	O
the	O
first	O
color	O
home	O
computer	O
on	O
the	O
market	O
,	O
very	O
nice	O
graphics	O
for	O
the	O
timeComx-35	O
and	O
clones1983CDP1869	O
CDP18703K1K	O
Video	O
ram	B-Architecture
and	O
2K	O
character	O
RAM	B-Architecture
for	O
128	O
programmable	O
characters	O
(	O
6×8	O
Bytes	O
NTSC	O
or	O
6×9	O
Bytes	O
PAL	O
,	O
RAM	B-Architecture
was	O
available	O
for	O
6×16	O
which	O
was	O
possible	O
to	O
use	O
via	O
assembler	O
code	O
)	O
40×24In	O
Assembler	O
the	O
width	O
and/or	O
height	O
of	O
the	O
characters	O
could	O
be	O
doubled	O
,	O
so	O
20×24	O
,	O
40×12	O
,	O
and	O
20×12	O
was	O
also	O
possible	O
8	O
foreground	O
colors	O
(	O
4	O
per	O
6×8	O
or	O
6×9	O
pixels	O
,	O
1	O
per	O
6-pixel	O
line	O
)	O
+	O
8	O
background	O
colors	O
(	O
for	O
the	O
whole	O
screen	O
)	O
"	O
Full	O
"	O
:	O
Limited	O
240×	O
192(NTSC )	O
/240x216	O
(	O
PAL	O
)	O
/240x384	O
(	O
expanded	O
RAM	B-Architecture
)	O
Using	O
a	O
programmable	O
font	O
(	O
with	O
128	O
characters	O
6	O
pixels	O
wide	O
and	O
9	O
pixels	O
high	O
)	O
that	O
meant	O
that	O
not	O
each	O
pixel	O
of	O
the	O
theoretical	O
240×192	O
,	O
240x216	O
or	O
240x384	O
could	O
be	O
individually	O
addressed	O
.	O
</s>
<s>
Semi	O
:	O
160×100160×200	O
with	O
an	O
expansion	O
optionMost	O
probably	O
the	O
PC-8001	B-Device
used	O
a	O
pseudo	O
graphics	O
mode	O
based	O
on	O
the	O
80×25	O
text	O
screen	O
with	O
a	O
2×4	O
(	O
2x8	O
with	O
expansion	O
)	O
pseudo	O
graphics	O
matrix	O
.	O
</s>
<s>
System	O
name	O
Year	O
Chip	O
name	O
Video	O
mode(s )	O
color	O
resolution	O
Font	O
extras	O
HW	O
accel	O
Sprite	O
details	O
TextGraphics	O
Acorn	B-Device
Atom	I-Device
,	O
APF	B-Device
Imagination	I-Device
Machine	I-Device
,	O
GEM	O
1000	O
/	O
Charlemagne	O
999	O
,	O
The	O
Rabbit	O
83	O
is	O
probably	O
a	O
copy	O
of	O
the	O
Belgian	O
GEM	O
1000	O
,	O
and	O
was	O
also	O
brought	O
out	O
,	O
with	O
more	O
memory	O
,	O
as	O
the	O
Brazilian	O
MC-1000	O
.	O
</s>
<s>
Unlike	O
many	O
other	O
MC6847	B-General_Concept
based	O
systems	O
(	O
CoCo	O
clones	O
)	O
it	O
did	O
n't	O
use	O
all	O
Motorola	O
chips	O
,	O
like	O
the	O
6809	B-Device
CPU	B-Device
.	O
</s>
<s>
Instead	O
it	O
used	O
a	O
Z80	B-General_Concept
,	O
and	O
the	O
General	B-Device
Instrument	I-Device
AY-3-8910	I-Device
sound	O
chip	O
.	O
</s>
<s>
+System	O
nameYearChip	O
nameVideo	O
RAMVideo	O
mode(s )	O
color	O
resolutionFont	O
extrassoft	O
fontspalette	O
supportHW	O
accelSprite	O
detailsunique	O
featuresTextGraphicsVIC-201980VICor	O
'	O
Video	O
interface	O
controller	O
 '	O
,	O
Pertaining	O
to	O
the	O
MOS	B-General_Concept
technology	I-General_Concept
6560	I-General_Concept
(	O
NTSC	O
version	O
)	O
and	O
the	O
6561	O
(	O
PAL	O
version	O
)	O
chips	O
.	O
</s>
<s>
These	O
chips	O
did	O
more	O
than	O
supporting	O
the	O
video	O
display	O
,	O
they	O
also	O
provided	O
the	O
sound	O
system	O
,	O
and	O
had	O
two	O
A/D	O
converters	O
for	O
its	O
paddle	O
game	O
control	O
system506	O
bytes	O
+	O
506	O
nibblesThe	O
VIC	B-General_Concept
chip	O
in	O
and	O
of	O
itself	O
could	O
address	O
16K	O
of	O
address	O
space	O
for	O
screen	O
and	O
character	O
memory	O
.	O
</s>
<s>
But	O
only	O
the	O
5K	O
that	O
points	O
to	O
internal	O
RAM	B-Architecture
can	O
be	O
used	O
by	O
it	O
on	O
the	O
VIC-20	B-Device
(	O
even	O
with	O
a	O
RAM	B-Architecture
expansion	O
module	O
plugged	O
in	O
)	O
without	O
a	O
hardware	O
modification	O
,	O
and	O
the	O
unexpanded	O
VIC-20	B-Device
only	O
had	O
a	O
grand	O
total	O
of	O
5K	O
of	O
which	O
only	O
512	O
bytes	O
was	O
reserved	O
for	O
the	O
screen	O
;	O
character	O
shape	O
data	O
was	O
2K	O
but	O
normally	O
came	O
from	O
ROM	B-Device
,	O
not	O
RAM	B-Architecture
.	O
</s>
<s>
Semi	O
:	O
technically	O
44x46	O
16	O
colors	O
(	O
upper	O
8	O
unusable	O
as	O
foreground	O
)	O
using	O
part	O
of	O
its	O
PETSCII	B-Protocol
character	O
setPETSCII	O
contained	O
2x2	O
block	O
graphics	O
characters	O
,	O
and	O
the	O
22x23	O
standard	O
for	O
the	O
VIC-20	B-Device
firmware	O
text	O
screen	O
was	O
enough	O
for	O
PETSCII	B-Protocol
block	O
graphics	O
to	O
significantly	O
beat	O
the	O
Apple	B-Device
II	I-Device
's	O
block	O
graphics	O
mode	O
,	O
although	O
mysteriously	O
nobody	O
really	O
cared	O
much	O
about	O
that	O
at	O
the	O
time.22	O
×23LC	O
,	O
BG	O
,	O
SGLike	O
on	O
the	O
PET	B-Device
,	O
256	O
different	O
characters	O
could	O
be	O
displayed	O
at	O
a	O
time	O
,	O
normally	O
taken	O
from	O
one	O
of	O
the	O
two	O
character	O
generators	O
in	O
ROM	B-Device
(	O
one	O
for	O
upper-case	O
letters	O
and	O
simple	O
graphics	O
,	O
the	O
other	O
for	O
mixed-case	O
--	O
non-English	O
characters	O
were	O
not	O
provided	O
)	O
Yesnot	O
really	O
,	O
but	O
something	O
similar	O
could	O
be	O
done	O
by	O
manipulating	O
the	O
four	O
colors	O
out	O
of	O
sixteen	O
chosen	O
for	O
each	O
tile	O
,	O
or	O
the	O
global	O
background	O
colorThe	O
VIC	B-General_Concept
chip	O
allowed	O
a	O
character	O
generator	O
in	O
RAM	B-Architecture
to	O
redefine	O
the	O
pixel-by-pixel	O
depictions	O
of	O
the	O
on-screen	O
characters	O
and	O
it	O
allowed	O
for	O
double-height	O
characters	O
(	O
8	O
pixels	O
wide	O
,	O
16	O
pixels	O
high	O
)	O
.	O
</s>
<s>
It	O
was	O
possible	O
to	O
get	O
a	O
fully	O
addressable	O
160	O
by	O
160	O
screen	O
by	O
filling	O
the	O
screen	O
with	O
a	O
sequence	O
of	O
200	O
different	O
double-height	O
characters	O
,	O
then	O
turning	O
on	O
the	O
pixels	O
selectively	O
inside	O
the	O
RAM-based	O
character	O
definitions	O
.	O
</s>
<s>
The	O
200-character	O
limitation	O
was	O
so	O
that	O
enough	O
bytes	O
would	O
be	O
left	O
over	O
for	O
the	O
screen	O
character	O
grid	O
itself	O
to	O
remain	O
addressable	O
by	O
the	O
VIC	B-General_Concept
chip	O
.	O
</s>
<s>
(	O
semi	O
:	O
80×50	O
16	O
colors	O
using	O
part	O
of	O
its	O
pseudo	O
graphic	O
characters	O
set	O
)	O
40x251	O
(	O
320	O
px	O
)	O
or	O
3	O
(	O
160	O
px	O
)	O
foreground	O
+	O
1	O
background	O
out	O
of	O
121NoneSomeIncluded	O
three	O
interval	O
timersIBM	O
PCjr	B-Device
&	O
Tandy	O
10001984	O
"	O
Video	O
Gate	O
Array	O
"	O
+	O
6845	B-General_Concept
(	O
PCjr	B-Device
)	O
Not	O
to	O
be	O
confused	O
with	O
VGA	B-Protocol
.	O
</s>
<s>
Also	O
known	O
as	O
"	O
CGA	B-Device
plus	O
"	O
,	O
the	O
PCjr	B-Device
video	O
subsystem	O
consisted	O
of	O
the	O
Video	O
Gate	O
Array	O
,	O
the	O
6845	B-General_Concept
,	O
and	O
some	O
discrete	O
logic	O
.	O
</s>
<s>
except	O
A7000( +	O
)	O
1987VIDC1480KB	O
(	O
from	O
system	O
RAM	B-Architecture
)	O
Text	O
sized	O
by	O
software	O
in	O
Flexible	O
Graphics	O
,	O
no	O
more	O
than	O
256	O
colors	O
(	O
e.g.	O
</s>
<s>
Modes	O
are	O
limited	O
only	O
by	O
analog	O
video	O
bandwidth	O
,	O
video	O
RAM	B-Architecture
,	O
or	O
DRAM	O
bandwidth	O
and	O
the	O
minimum	O
refresh	O
rate	O
monitor	O
will	O
accept	O
.	O
</s>
<s>
System	O
name	O
Year	O
Chip	O
name	O
Video	O
RAM	B-Architecture
Video	O
mode(s )	O
color	O
resolution	O
Font	O
extras	O
soft	O
fonts	O
palette	B-Data_Structure
support	O
HW	O
accel	O
Sprite	O
details	O
unique	O
featuresTextGraphics	O
Atari	B-Device
8-bit	I-Device
familyIncluding	O
the	O
Atari	O
400	O
,	O
600XL	B-Device
,	O
800/XE/XL	O
,	O
65XE	B-Device
,	O
1200XL	B-Device
and	O
130XE	B-Device
.	O
</s>
<s>
1979	O
ANTIC	B-General_Concept
plus	O
CTIA/GTIA	B-General_Concept
18K+	O
of	O
64KThe	O
extremely	O
flexible	O
ANTIC	B-General_Concept
chip	O
can	O
access	O
the	O
entire	O
64K	O
of	O
addressable	O
memory	O
space	O
.	O
</s>
<s>
However	O
,	O
since	O
multiple	O
redefined	O
character	O
sets	O
are	O
possible	O
the	O
maximum	O
amount	O
of	O
memory	O
in	O
use	O
by	O
ANTIC	B-General_Concept
could	O
be	O
even	O
higher	O
than	O
18K	O
.	O
</s>
<s>
Scrolling	O
map	O
memory	O
can	O
occupy	O
any	O
amount	O
of	O
available	O
RAM	B-Architecture
.	O
</s>
<s>
Custom	O
display	O
lists	O
can	O
use	O
fewer	O
or	O
more	O
lines	O
into	O
the	O
display	O
overscan	O
area	O
limited	O
to	O
the	O
hardware	O
's	O
240	O
maximum	O
scan	B-Algorithm
lines	I-Algorithm
of	O
playfield	O
graphics	O
.	O
</s>
<s>
ANTIC	B-General_Concept
also	O
supports	O
a	O
specific	O
"	O
Lowercase	O
with	O
descenders	O
"	O
mode	O
as	O
part	O
of	O
custom	O
display	O
lists	O
,	O
which	O
is	O
not	O
available	O
via	O
a	O
BASIC	O
GRAPHICS	O
mode	O
command	O
.	O
</s>
<s>
This	O
is	O
not	O
strictly	O
speaking	O
a	O
40×24	O
text	B-Application
mode	I-Application
,	O
because	O
of	O
the	O
unusual	O
height	O
.	O
</s>
<s>
YesThe	O
character	O
set	O
was	O
easily	O
redirected	O
by	O
changing	O
an	O
ANTIC	B-General_Concept
register	O
,	O
allowing	O
the	O
user	O
to	O
create	O
their	O
own	O
character	O
sets	O
with	O
relative	O
ease	O
,	O
or	O
built	O
out	O
of	O
the	O
CTIA/GTIA	B-General_Concept
'	O
s	O
P/M	O
Graphics	O
as	O
had	O
to	O
be	O
done	O
with	O
the	O
TIA	O
of	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
.	O
</s>
<s>
16	O
out	O
of	O
128	O
(	O
with	O
FGTIA	O
or	O
GTIA	B-General_Concept
)	O
or	O
256	O
(	O
only	O
with	O
GTIA	B-General_Concept
)	O
SP	O
,	O
SC	O
S#=	O
4+4	O
or	O
5	O
SS=	O
8	O
+	O
2	O
or	O
5×	O
256(max )	O
SC	O
=	O
1	O
SP	O
=	O
4+4	O
or	O
5	O
Many	O
,	O
especially	O
hardware	O
support	O
for	O
a	O
Light	B-Device
pen	I-Device
and	O
the	O
Display	O
list	O
.	O
</s>
<s>
Coleco	B-Device
Adam	I-Device
,	O
VTech	B-General_Concept
CreatiVision	I-General_Concept
,	O
MSX1	O
,	O
MSX	B-Operating_System
was	O
n't	O
a	O
single	O
machine	O
,	O
but	O
a	O
standard	O
that	O
was	O
followed	O
by	O
various	O
manufacturers	O
.	O
</s>
<s>
But	O
from	O
the	O
perspective	O
of	O
the	O
video	O
hardware	O
,	O
all	O
MSX1	O
systems	O
are	O
the	O
same	O
,	O
as	O
they	O
use	O
the	O
same	O
video	B-General_Concept
display	I-General_Concept
generator	I-General_Concept
with	O
16K	O
of	O
Video-RAM	O
.	O
</s>
<s>
Pencil	O
2	O
,	O
Memotech	B-Device
MTX	I-Device
,	O
The	O
Memotech	B-Device
MTX500	I-Device
,	O
MTX512A	O
and	O
RS128	B-Device
machines	O
all	O
have	O
the	O
same	O
video	O
capabilities	O
Sega	O
SC-3000	O
,	O
Sord	B-Device
M5	I-Device
,	O
SV-318	B-Device
and	O
SV-328	B-Device
,	O
Tatung	B-Operating_System
Einstein	I-Operating_System
,	O
TI-99/4	B-Device
,	O
TI-99/4A	B-Device
,	O
Tomy	O
Tutor/Pyuuta	O
1979-1984	O
TMS9918Athe	O
TMS9918	B-Architecture
is	O
actually	O
a	O
family	O
of	O
devices	O
.	O
</s>
<s>
The	O
TMS9918A	B-Architecture
outputs	O
60	O
Hz	O
NTSC	O
composite	O
video	O
and	O
TMS9928	B-Architecture
and	O
TMS9929	O
output	O
three	O
separate	O
signals	O
(	O
Y	O
,	O
R-Y	O
and	O
B-Y	O
)	O
with	O
which	O
either	O
a	O
60	O
Hz	O
NTSC	O
(	O
TMS9928A	O
)	O
or	O
a	O
50	O
Hz	O
PAL	O
or	O
SECAM	O
(	O
TMS9929A	O
)	O
video	B-Application
signal	I-Application
could	O
be	O
created	O
16K	O
32×	O
24TMS9918/28	O
based	O
systems	O
:	O
in	O
32×24	O
text	B-Application
mode	I-Application
the	O
character	O
set	O
is	O
divided	O
in	O
32	O
blocks	O
of	O
eight	O
characters	O
.	O
</s>
<s>
This	O
can	O
be	O
used	O
in	O
games	O
,	O
because	O
it	O
is	O
possible	O
to	O
generate	O
a	O
relatively	O
fast	O
high-resolution	O
mode	O
by	O
reprogramming	O
the	O
characters	O
as	O
8×8	O
tiles	B-Algorithm
and	O
grouping	O
them	O
together	O
in	O
blocks	O
of	O
eight	O
with	O
the	O
same	O
colors	O
.	O
</s>
<s>
The	O
tiles	B-Algorithm
can	O
then	O
be	O
manipulated	O
quickly	O
through	O
the	O
character	B-Application
pointer	I-Application
table	I-Application
.	O
</s>
<s>
with	O
this	O
character	O
set	O
,	O
it	O
is	O
possible	O
to	O
create	O
a	O
32×24	O
text	B-Application
mode	I-Application
that	O
can	O
display	O
texts	O
with	O
four	O
different	O
foreground	O
and	O
background	O
colors	O
at	O
the	O
same	O
time	O
,	O
on	O
the	O
same	O
screen	O
.	O
</s>
<s>
Semi	O
:	O
64×48	O
16	O
colors	O
32x24	O
,	O
32×192	O
LC	O
,	O
(	O
BG	O
,	O
SG	O
)	O
the	O
MTX	O
character	O
set	O
included	O
only	O
lowercase	O
lettersExcept	O
for	O
the	O
ASCII	B-Protocol
character	I-Protocol
set	I-Protocol
the	O
MSX	B-Operating_System
standard	O
did	O
not	O
define	O
the	O
character	O
set	O
,	O
however	O
,	O
most	O
MSX	B-Operating_System
systems	O
sold	O
in	O
the	O
West	O
did	O
have	O
among	O
Greek	O
and	O
other	O
alphabets	O
a	O
large	O
set	O
of	O
semi	O
graphical	O
characters	O
including	O
some	O
for	O
block	O
graphics	O
.	O
</s>
<s>
Some	O
systems	O
even	O
had	O
the	O
pseudo	O
graphic	O
characters	O
printed	O
on	O
their	O
keysYesNoneSP	O
,	O
TE	O
S#=	O
32	O
SS=	O
8×8	O
,	O
16×16	O
SC	O
=	O
1	O
SP	O
=	O
4	O
The	O
TMS9918	B-Architecture
was	O
designed	O
for	O
the	O
TI-99/4	B-Device
,	O
it	O
has	O
text	O
characters	O
of	O
8x8	O
(	O
32	O
characters	O
per	O
line	O
)	O
or	O
8x6	O
pixels	O
(	O
40	O
characters	O
per	O
line	O
,	O
and	O
features	O
limited	O
attribute	B-Algorithm
clash	I-Algorithm
colour	O
limitations	O
,	O
it	O
has	O
32	O
monochrome	O
sprites	O
of	O
8x8	O
or	O
16x16	O
pixels	O
.	O
</s>
<s>
MSX2	B-Operating_System
,	O
MSX2+	B-Operating_System
/TurboRSecond	O
through	O
fourth	O
revisions	O
of	O
MSX	B-Operating_System
standard	O
,	O
significantly	O
extending	O
the	O
machine	O
's	O
capabilities	O
.	O
</s>
<s>
Most	O
notable	O
change	O
was	O
the	O
so-called	O
MSX-video	B-General_Concept
chip	I-General_Concept
--	O
an	O
upgraded	O
version	O
of	O
the	O
TMS9918	B-Architecture
VDP	B-General_Concept
used	O
in	O
MSX-1	O
machines	O
--	O
and	O
its	O
upgraded	O
version	O
the	O
Yamaha	B-General_Concept
V9958	I-General_Concept
,	O
and	O
a	O
corresponding	O
memory	O
upgrade	O
.	O
</s>
<s>
1986	O
,	O
1988	O
Yamaha	B-General_Concept
V9938	I-General_Concept
,	O
Yamaha	B-General_Concept
V9958	I-General_Concept
64K	O
,	O
128K	O
,	O
or	O
192KDepending	O
on	O
manufacturer	O
or	O
revision	O
.	O
</s>
<s>
32×24	O
,	O
32×	O
26.5	O
16	O
colors	O
,	O
40×24	O
,	O
40×	O
26.5	O
2	O
colors	O
,	O
80×24	O
or	O
80×	O
26.526.5	O
rows	O
are	O
n't	O
supported	O
by	O
default	O
by	O
MSX	B-Language
BASIC	I-Language
,	O
but	O
it	O
's	O
easy	O
to	O
enable	O
it	O
.	O
</s>
<s>
SP	O
=	O
8	O
Many	O
unique	O
featuresMSX2	O
machines	O
and	O
higher	O
featured	O
advanced	O
VDP	B-General_Concept
,	O
that	O
was	O
somewhat	O
similar	O
in	O
abilities	O
to	O
the	O
Amiga	B-Device
one	O
.	O
</s>
<s>
It	O
was	O
able	O
to	O
do	O
hardware-accelerated	B-General_Concept
scrolling	O
,	O
bit	O
copy	O
(	O
with	O
logical	O
operations	O
)	O
,	O
line	B-Algorithm
drawing	I-Algorithm
,	O
area-filling	O
,	O
and	O
even	O
included	O
overlay	O
support	O
,	O
digitization	O
,	O
mouse	O
and	O
light	B-Device
pen	I-Device
ports	O
.	O
</s>
<s>
Several	O
VDP	B-General_Concept
exceptions	O
,	O
such	O
as	O
sprite	O
collision	O
and	O
backtracking	O
,	O
had	O
special	O
status	O
flags	O
that	O
,	O
with	O
skillful	O
manipulation	O
of	O
VDP	B-General_Concept
registers	O
,	O
allowed	O
for	O
many	O
visual	O
tricks.P2000Tthe	O
P2000M	O
had	O
nothing	O
to	O
do	O
with	O
the	O
P2000T	B-Device
;	O
it	O
was	O
a	O
CP/M	B-Application
business	O
machine	O
without	O
any	O
special	O
video	O
attributes	O
,	O
just	O
80×24	O
text	O
1980	O
SAA5243Essentially	O
Philips	O
(	O
a	O
TV	O
maker	O
)	O
simply	O
used	O
a	O
video	B-General_Concept
chip	I-General_Concept
used	O
in	O
their	O
TVs	O
for	O
the	O
display	O
of	O
Teletext	O
,	O
I	O
believe	O
it	O
was	O
the	O
SAA5243	B-General_Concept
but	O
am	O
not	O
completely	O
sure	O
,	O
as	O
Philips	O
used	O
many	O
different	O
Teletext	O
chips	O
.	O
</s>
<s>
+System	O
nameYearChip	O
nameVideo	O
RAMVideo	O
mode(s )	O
color	O
resolutionFont	O
extrassoft	O
fontspalette	O
supportHW	O
accelSprite	O
detailsunique	O
featuresFM-71982MC680948K	O
,	O
96	O
or	O
144K	O
in	O
AV	O
mode96K	O
for	O
FM-77AV	O
and	O
AV20	O
,	O
144K	O
for	O
FM-77AV4040	O
×25	O
or	O
40×20	O
Text	O
in	O
320x200The	O
FM-77AV	O
used	O
twelve	O
(	O
AV	O
and	O
AV20	O
)	O
or	O
eighteen	O
(	O
AV40	O
)	O
"	O
graphics	O
planes	O
"	O
,	O
four	O
(	O
AV	O
and	O
AV20	O
)	O
or	O
six	O
(	O
AV40	O
)	O
for	O
each	O
primary	O
color	O
,	O
each	O
plane	O
had	O
one	O
bit	O
for	O
each	O
pixel	O
,	O
so	O
it	O
used	O
8000	O
bytes	O
,	O
so	O
192	O
bytes	O
per	O
plane	O
went	O
unused	O
Graphics	O
4096	O
colors	O
for	O
FM-77AV	O
and	O
AV20	O
or	O
262144	O
colors	O
for	O
FM-77AV40	O
or	O
80×25	O
,	O
80×20	O
Text	O
in	O
640x200The	O
FM-7	B-Device
used	O
three	O
"	O
graphics	O
planes	O
"	O
,	O
one	O
for	O
each	O
primary	O
color	O
,	O
each	O
plane	O
had	O
one	O
bit	O
for	O
each	O
pixel	O
,	O
so	O
it	O
used	O
16000	O
bytes	O
,	O
so	O
384	O
bytes	O
per	O
plane	O
went	O
unused	O
Graphics	O
8	O
colors320x200	O
or	O
640x200LCYesNone320x200x4096	O
colors	O
for	O
FM-77AV	O
and	O
AV20	O
or	O
262144	O
colors	O
for	O
FM-77AV40	O
and	O
640×200×8	O
colors	O
without	O
color	O
limitationsdue	O
to	O
its	O
use	O
of	O
a	O
separate	O
6809	B-Device
processor	O
for	O
graphics	O
,	O
the	O
FM-7	B-Device
could	O
use	O
a	O
massive	O
48K	O
of	O
RAM	B-Architecture
for	O
three	O
16K	O
bit	O
planes	O
each	O
using	O
16000	O
bytes	O
,	O
and	O
the	O
FM-77AV	O
could	O
use	O
an	O
even	O
more	O
massive	O
96K	O
(	O
AV	O
and	O
AV20	O
)	O
or	O
144K	O
(	O
AV40	O
)	O
but	O
only	O
for	O
8K	O
bit	O
planes	O
each	O
using	O
8000	O
bytes	O
(	O
why	O
Fujitsu	O
made	O
this	O
decision	O
is	O
a	O
mystery	O
)	O
,	O
that	O
way	O
it	O
could	O
have	O
pixels	O
with	O
twelve	O
or	O
eighteen	O
bits	O
to	O
call	O
their	O
own	O
respectively	O
.	O
</s>
<s>
The	O
remaining	O
16K	O
or	O
more	O
(	O
32	O
or	O
112K	O
for	O
FM-77AV	O
and	O
AV20	O
or	O
48	O
or	O
176K	O
for	O
FM-77AV40	O
)	O
of	O
RAM	B-Architecture
was	O
used	O
to	O
store	O
fonts	O
and	O
drawing	O
routines	O
.	O
</s>
<s>
To	O
communicate	O
with	O
the	O
main	O
CPU	B-Device
the	O
FM-7	B-Device
used	O
a	O
shared	O
memory	O
system	O
,	O
not	O
unlike	O
the	O
"	O
Tube	B-Device
"	O
of	O
the	O
BBC	O
Micro.Amiga	O
(	O
first	O
generation	O
)	O
Pertaining	O
to	O
the	O
Amiga	B-Device
1000	O
,	O
Amiga	B-Device
2000	O
and	O
Amiga	B-Device
500	O
machines1985AgnusFor	O
DMA	O
memory	O
access	O
and	O
Blitter	B-General_Concept
functions	O
,	O
and	O
a	O
Copper	O
(	O
co-processor	O
)	O
,	O
a	O
programmable	O
finite	O
state	O
machine	O
that	O
executes	O
a	O
programmed	O
instruction	O
stream	O
,	O
synchronized	O
with	O
the	O
video	O
hardware	O
and	O
Denisethe	O
main	O
video	O
processor	O
.	O
</s>
<s>
Anything	O
between	O
2	O
and	O
32	O
unique	O
colors	O
(	O
1	O
to	O
5	O
bitplanes	O
)	O
from	O
a	O
12	O
bit	O
(	O
4096	O
colors	O
)	O
palette	B-Data_Structure
,	O
was	O
supported	O
.	O
</s>
<s>
For	O
more	O
information	O
see	O
Original	O
Amiga	B-Device
chipset.1M	O
"	O
Chip	O
RAM	B-Architecture
"	O
Older	O
versions	O
could	O
only	O
access	O
512K	O
Chip	O
RAMAny	O
Text	O
size	O
up	O
to	O
80×32	O
(	O
80x64	O
in	O
interlaced	O
mode	O
)	O
All	O
text	O
output	O
rendered	O
by	O
Blitter	B-General_Concept
or	O
software	O
in	O
any	O
graphics	O
mode	O
in	O
320×200p	O
,	O
640×200p	O
,	O
320×400i	O
or	O
640×400i320×256p	O
,	O
640×256p	O
,	O
320×512i	O
or	O
640×512i	O
in	O
PAL	O
mode	O
Graphics	O
2	O
to	O
64	O
colors	O
and	O
4096	O
colors320×200p	O
,	O
640×200p	O
,	O
320×400i	O
or	O
640×400iLCYes2	O
to	O
32	O
colors	O
out	O
of	O
4096	O
colorsBL	O
,	O
SP	O
,	O
SC	O
,	O
DRS#	O
=	O
8The	O
Amiga	B-Device
's	O
hardware	O
engine	O
supports	O
only	O
8	O
sprites	O
,	O
but	O
with	O
copper	O
support	O
,	O
can	O
present	O
the	O
illusion	O
of	O
many	O
more	O
.	O
</s>
<s>
SP	O
=	O
8Many	O
unique	O
featuresToo	O
many	O
to	O
mention	O
,	O
see	O
Original	O
Amiga	B-Device
chipsetAmiga	O
(	O
second	O
generation	O
)	O
Pertaining	O
to	O
the	O
Amiga	B-Device
3000	O
machines1990Super-Agnus	O
and	O
Hires	O
DeniseCould	O
do	O
all	O
the	O
things	O
the	O
original	O
Agnus	B-Device
chip	O
could	O
and	O
added	O
support	O
for	O
Productivity	O
(	O
640×480	O
noninterlaced	O
)	O
and	O
Super	O
Highres	O
(	O
1280×200	O
or	O
1280×256	O
)	O
display	O
modes	O
,	O
which	O
were	O
however	O
limited	O
to	O
only	O
4	O
colors	O
.	O
</s>
<s>
Also	O
the	O
blitter	B-General_Concept
could	O
copy	O
regions	O
larger	O
than	O
1024×1024	O
pixels	O
in	O
one	O
operation	O
.	O
</s>
<s>
PAL	O
:	O
320x256	O
,	O
640x256	O
,	O
320x512	O
,	O
640x512	O
,	O
1280×256p	O
or	O
1280x512ieven	O
more	O
unique	O
featuresEven	O
more	O
features	O
than	O
the	O
original	B-Device
chipset	I-Device
,	O
see	O
Enhanced	O
Amiga	B-Device
chipsetAmiga	O
(	O
Third	O
generation	O
)	O
used	O
in	O
the	O
CD32	B-Device
,	O
Amiga	B-Device
1200	O
and	O
Amiga	B-Device
4000.1992Advanced	O
Graphics	O
Architecture	O
(	O
AGA	B-Device
)	O
AGA	B-Device
is	O
able	O
to	O
do	O
8-bit	O
pixels	O
,	O
which	O
gives	O
256	O
colors	O
in	O
normal	O
display	O
mode	O
and	O
262144	O
colors	O
in	O
HAM-8	O
(	O
Hold-And-Modify	O
)	O
mode	O
(	O
18-bit	O
color	O
,	O
6	O
bits	O
per	O
RGB	O
channel	O
)	O
.	O
</s>
<s>
Palette	B-Data_Structure
for	O
AGA	B-Device
chipset	O
is	O
256	O
entries	O
from	O
16,777,216	O
colors	O
(	O
24-bit	O
)	O
.	O
</s>
<s>
(	O
semi	O
:	O
80×50	O
,	O
160x50	O
or	O
160x100	O
16	O
colors	O
using	O
part	O
of	O
its	O
pseudo	O
graphic	O
characters	O
set	O
)	O
40x25	O
(	O
40	O
column	O
mode	O
)	O
,	O
640x200	O
or	O
640x400	O
(	O
80	O
column	O
mode	O
)	O
1	O
(	O
320	O
px	O
)	O
or	O
3	O
(	O
160	O
px	O
)	O
foreground	O
+	O
1	O
background	O
out	O
of	O
16	O
(	O
40	O
column	O
mode	O
)	O
SP	O
,	O
SC	O
(	O
40	O
column	O
mode	O
)	O
;	O
BL	O
(	O
80	O
column	O
mode	O
)	O
S#=	O
8	O
SS=	O
24×21	O
,	O
12×21	O
SC	O
=	O
1	O
SP	O
=	O
8	O
(	O
40	O
column	O
mode	O
)	O
Uses	O
two	O
different	O
video	O
circuitsUnique	O
in	O
that	O
the	O
system	O
contained	O
two	O
different	O
video	O
circuits	O
with	O
separate	O
outputs	O
Amstrad	B-Device
CPC	I-Device
1984	O
,	O
1990	O
MC6845+ASIC	O
16K	O
20×25	O
16	O
colors	O
,	O
40×25	O
4	O
colors	O
or	O
80×25All	O
text	O
output	O
produced	O
by	O
software	O
in	O
high-res	O
graphics	O
modesFullscreen	O
up	O
to	O
26x36	O
,	O
52x36	O
,	O
104x36	O
2	O
colors160×200	O
16	O
colors	O
,	O
320×200	O
4	O
colors	O
or	O
640×200Fullscreen	O
up	O
to	O
208x288	O
,	O
416x288	O
,	O
832x288	O
2	O
colors160×200	O
,	O
320×200	O
or	O
640×200	O
LC	O
Yes	O
17	O
of	O
27	O
(	O
original	O
)	O
,	O
32	O
of	O
4096	O
(	O
Plus	O
)	O
SC	O
,	O
SP	O
(	O
Plus	O
)	O
S#=	O
16with	O
an	O
independent	O
palette	B-Data_Structure
of	O
15	O
colors	O
,	O
but	O
sprite	O
pixels	O
can	O
also	O
be	O
transparent	O
,	O
and	O
each	O
logical	O
color	O
can	O
be	O
any	O
of	O
4096	O
colors	O
SS=	O
16×16three	O
levels	O
of	O
magnification	O
,	O
1×	O
,	O
2×	O
and	O
4×	O
.	O
</s>
<s>
Semi	O
:	O
80×75using	O
the	O
2×3	O
block	O
graphics	O
of	O
teletext	O
mode	O
8	O
colors640×256	O
,	O
320×256	O
,	O
160×256	O
,	O
640×200	O
or	O
320×200	O
;	O
40x25	O
LC	O
,	O
BG	O
No	O
16Modes	O
0	O
to	O
6	O
could	O
display	O
a	O
choice	O
of	O
colors	O
from	O
a	O
logical	O
palette	B-Data_Structure
of	O
sixteen	O
,	O
though	O
only	O
eight	O
colors	O
were	O
available	O
;	O
the	O
eight	O
basic	O
RGB	O
colors	O
(	O
0-black	O
,	O
1-red	O
,	O
2-green	O
,	O
3-yellow	O
,	O
4-blue	O
,	O
5-magenta	O
,	O
6-cyan	O
,	O
7-white	O
)	O
and	O
eight	O
colors	O
in	O
a	O
flashing	O
state	O
,	O
(	O
8-black/white	O
,	O
9-red/cyan	O
,	O
10-green/magenta	O
,	O
11-yellow/blue	O
,	O
12-blue/yellow	O
,	O
13-magenta/green	O
,	O
14-cyan/red	O
,	O
15-white/black	O
)	O
None	O
Teletext	O
mode	O
,	O
shadow	O
RAM	B-Architecture
supportMode	O
7	O
was	O
a	O
Teletext	O
mode	O
and	O
extremely	O
economfical	O
on	O
memory	O
,	O
using	O
only	O
1K	O
,	O
In	O
addition	O
,	O
the	O
BBC	O
B+	O
and	O
the	O
later	O
Master	O
allowed	O
'	O
shadow	O
modes	O
 '	O
,	O
where	O
the	O
framebuffer	B-Algorithm
was	O
stored	O
in	O
20	O
K	O
of	O
extra	O
RAM	B-Architecture
mapped	O
to	O
location	O
0x8000	O
onwards	O
( 	O
 '	O
shadowing	O
 '	O
the	O
BASIC	O
ROM	B-Device
mapped	O
to	O
that	O
area	O
)	O
,	O
instead	O
of	O
taking	O
up	O
the	O
user	O
memory	O
below	O
0x8000	O
.	O
</s>
<s>
Semi	O
:	O
80×72Teletext	O
graphics	O
,	O
using	O
text	B-Data_Structure
semigraphics	I-Data_Structure
characters	O
,	O
unlike	O
the	O
TRS-80	B-Device
the	O
pseudo	O
graphics	O
characters	O
came	O
in	O
two	O
kinds	O
,	O
"	O
massive	O
"	O
and	O
"	O
separate	O
"	O
,	O
the	O
first	O
is	O
exactly	O
like	O
the	O
TRS-80	B-Device
,	O
the	O
second	O
has	O
each	O
"	O
pixel	O
block	O
"	O
surrounded	O
by	O
a	O
narrow	O
line	O
of	O
background	O
color	O
8	O
colors240x204	O
or	O
480x204	O
,	O
40×24NoneSharp	O
X680001987VINAS	O
1	O
+	O
2	O
,	O
VSOP	O
,	O
CYNTHIA	O
/	O
Jr	O
,	O
RESERVEThe	O
two	O
main	O
CRT	O
Controller	O
chips	O
were	O
called	O
"	O
VINAS	O
1	O
+	O
2	O
"	O
,	O
later	O
models	O
used	O
a	O
chip	O
called	O
VICON	O
.	O
</s>
<s>
The	O
separate	O
"	O
Sprite	O
Controller	O
"	O
was	O
called	O
"	O
CYNTHIA	O
/	O
Jr	O
"	O
in	O
its	O
first	O
incarnation	O
,	O
and	O
later	O
just	O
"	O
CYNTHIA	O
"	O
,	O
then	O
last	O
but	O
not	O
least	O
there	O
was	O
the	O
"	O
Video	O
Data	O
Selector	O
"	O
first	O
called	O
(	O
strangely	O
enough	O
)	O
"	O
RESERVE	O
"	O
,	O
but	O
later	O
more	O
fanciful	O
"	O
CATHY	O
"	O
1056K512KB	O
Text	O
VRAM	O
,	O
512KB	O
Graphic	O
VRAM	O
,	O
32KB	O
Sprite	O
VRAMfrom	O
16×16	O
to	O
128×128The	O
X68000	B-Device
had	O
a	O
separate	O
768KB	O
Character	O
Generator	O
ROM	B-Device
,	O
with	O
fonts	O
for	O
16×16	O
,	O
8×16	O
,	O
8×8	O
and	O
JIS	O
1	O
+	O
2	O
characters	O
.	O
</s>
