<s>
The	O
ZX	B-Operating_System
Spectrum	I-Operating_System
(	O
)	O
is	O
an	O
8-bit	O
home	O
computer	O
that	O
was	O
developed	O
by	O
Sinclair	O
Research	O
.	O
</s>
<s>
It	O
was	O
released	O
in	O
the	O
United	O
Kingdom	O
on	O
23	O
April	O
1982	O
,	O
and	O
became	O
Britain	O
's	O
best-selling	O
microcomputer	B-Architecture
.	O
</s>
<s>
Referred	O
to	O
during	O
development	O
as	O
the	O
ZX81	O
Colour	O
and	O
ZX82	B-Operating_System
,	O
it	O
was	O
launched	O
as	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
to	O
highlight	O
the	O
machine	O
's	O
colour	O
display	O
,	O
which	O
differed	O
from	O
the	O
black	O
and	O
white	O
display	O
of	O
its	O
predecessor	O
,	O
the	O
ZX81	O
.	O
</s>
<s>
The	O
Spectrum	O
was	O
released	O
as	O
six	O
different	O
models	O
,	O
ranging	O
from	O
the	O
entry	O
level	O
with	O
16KB	O
RAM	B-Architecture
released	O
in	O
1982	O
to	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
+3	O
with	O
128KB	O
RAM	B-Architecture
and	O
built	O
in	O
floppy	B-Device
disk	I-Device
drive	I-Device
in	O
1987	O
;	O
altogether	O
they	O
sold	O
over	O
5	O
million	O
units	O
worldwide	O
(	O
not	O
counting	O
unofficial	B-Architecture
clones	I-Architecture
)	O
.	O
</s>
<s>
The	O
Spectrum	O
was	O
among	O
the	O
first	O
home	O
computers	O
in	O
the	O
United	O
Kingdom	O
aimed	O
at	O
a	O
mainstream	O
audience	O
,	O
and	O
it	O
thus	O
had	O
similar	O
significance	O
to	O
the	O
Commodore	O
64	O
in	O
the	O
US	O
and	O
the	O
Thomson	B-Device
MO5	I-Device
in	O
France	O
.	O
</s>
<s>
The	O
introduction	O
of	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
led	O
to	O
a	O
boom	O
in	O
companies	O
producing	O
software	O
and	O
hardware	B-Architecture
for	O
the	O
machine	O
,	O
the	O
effects	O
of	O
which	O
are	O
still	O
seen	O
.	O
</s>
<s>
The	O
Commodore	O
64	O
,	O
Dragon	B-Device
32	I-Device
,	O
Oric-1	O
,	O
Oric	O
Atmos	O
,	O
BBC	B-Device
Micro	I-Device
and	O
later	O
the	O
Amstrad	B-Device
CPC	I-Device
range	O
were	O
rivals	O
to	O
the	O
Spectrum	O
in	O
the	O
UK	O
market	O
during	O
the	O
early	O
1980s	O
.	O
</s>
<s>
The	O
Spectrum	O
is	O
based	O
on	O
a	O
Zilog	B-General_Concept
Z80	I-General_Concept
,	O
a	O
CPU	B-General_Concept
running	O
at	O
3.5MHz	O
(	O
or	O
NEC	O
D780C-1	B-Device
clone	O
)	O
.	O
</s>
<s>
The	O
original	O
model	O
has	O
16KB	O
(	O
16×1024	O
bytes	B-Application
)	O
of	O
ROM	B-Device
and	O
either	O
16KB	O
or	O
48KB	O
of	O
RAM	B-Architecture
.	O
</s>
<s>
Hardware	B-Architecture
design	O
was	O
by	O
Richard	O
Altwasser	O
of	O
Sinclair	O
Research	O
,	O
and	O
the	O
outward	O
appearance	O
was	O
designed	O
by	O
Sinclair	O
's	O
industrial	O
designer	O
Rick	O
Dickinson	O
.	O
</s>
<s>
Text	O
can	O
be	O
displayed	O
using	O
32columns	O
×	O
24rows	O
of	O
characters	O
from	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
character	O
set	O
or	O
from	O
a	O
set	O
provided	O
within	O
an	O
application	O
,	O
from	O
a	O
palette	O
of	O
15	O
shades	O
:	O
seven	O
colours	O
at	O
two	O
levels	O
of	O
brightness	O
each	O
,	O
plus	O
black	O
.	O
</s>
<s>
The	O
image	B-Algorithm
resolution	I-Algorithm
is	O
256×192	O
with	O
the	O
same	O
colour	O
limitations	O
.	O
</s>
<s>
To	O
conserve	O
memory	O
,	O
colour	O
is	O
stored	O
separate	O
from	O
the	O
pixel	O
bitmap	O
in	O
a	O
low	B-Algorithm
resolution	I-Algorithm
,	O
32×24	O
grid	O
overlay	O
,	O
corresponding	O
to	O
the	O
character	O
cells	O
.	O
</s>
<s>
This	O
scheme	O
leads	O
to	O
what	O
was	O
dubbed	O
colour	B-Algorithm
clash	I-Algorithm
or	O
attribute	B-Algorithm
clash	I-Algorithm
,	O
where	O
a	O
desired	O
colour	O
of	O
a	O
specific	O
pixel	O
could	O
not	O
necessarily	O
be	O
selected	O
.	O
</s>
<s>
Other	O
machines	O
available	O
around	O
the	O
same	O
time	O
,	O
for	O
example	O
the	O
Amstrad	B-Device
CPC	I-Device
or	O
the	O
Commodore	O
64	O
,	O
did	O
not	O
suffer	O
from	O
this	O
limitation	O
.	O
</s>
<s>
The	O
Commodore	O
64	O
used	O
colour	O
attributes	O
in	O
a	O
similar	O
way	O
,	O
but	O
a	O
special	O
multicolour	O
mode	O
and	O
hardware	B-Architecture
sprites	O
were	O
used	O
to	O
avoid	O
attribute	B-Algorithm
clash	I-Algorithm
.	O
</s>
<s>
The	O
machine	O
includes	O
an	O
expansion	B-Device
bus	I-Device
edge	O
connector	O
and	O
3.5mm	O
audio	O
in/out	O
ports	O
for	O
the	O
connection	O
of	O
a	O
cassette	O
recorder	O
for	O
loading	O
and	O
saving	O
programs	O
and	O
data	O
.	O
</s>
<s>
The	O
machine	O
's	O
Sinclair	B-Language
BASIC	I-Language
interpreter	O
is	O
stored	O
in	O
ROM	B-Device
(	O
along	O
with	O
fundamental	O
system-routines	O
)	O
and	O
was	O
written	O
by	O
Steve	O
Vickers	O
on	O
contract	O
from	O
Nine	O
Tiles	O
Ltd	O
.	O
</s>
<s>
The	O
Spectrum	O
's	O
chiclet	B-Device
keyboard	I-Device
(	O
on	O
top	O
of	O
a	O
membrane	O
,	O
similar	O
to	O
calculator	O
keys	O
)	O
is	O
marked	O
with	O
BASIC	O
keywords	O
.	O
</s>
<s>
The	O
BASIC	O
interpreter	O
was	O
developed	O
from	O
that	O
used	O
on	O
the	O
ZX81	O
and	O
a	O
ZX81	O
BASIC	O
program	O
can	O
be	O
typed	O
into	O
a	O
Spectrum	O
largely	O
unmodified	O
,	O
but	O
Spectrum	B-Language
BASIC	I-Language
included	O
many	O
extra	O
features	O
making	O
it	O
easier	O
to	O
use	O
.	O
</s>
<s>
The	O
ZX	B-Operating_System
Spectrum	I-Operating_System
character	O
set	O
was	O
expanded	O
from	O
that	O
of	O
the	O
ZX81	O
,	O
which	O
did	O
not	O
feature	O
lower-case	O
letters	O
.	O
</s>
<s>
Spectrum	B-Language
BASIC	I-Language
included	O
extra	O
keywords	O
for	O
the	O
more	O
advanced	O
display	O
and	O
sound	O
,	O
and	O
supported	O
multi-statement	O
lines	O
.	O
</s>
<s>
Rick	O
Dickinson	O
came	O
up	O
with	O
a	O
number	O
of	O
designs	O
for	O
the	O
"	O
ZX82	B-Operating_System
"	O
project	O
before	O
the	O
final	O
ZX	B-Operating_System
Spectrum	I-Operating_System
design	O
.	O
</s>
<s>
The	O
Spectrum	O
reused	O
a	O
number	O
of	O
design	O
elements	O
of	O
the	O
ZX81	O
:	O
The	O
ROM	B-Device
code	O
for	O
things	O
such	O
as	O
floating	B-Algorithm
point	I-Algorithm
calculations	O
and	O
expression	B-Language
parsing	I-Language
were	O
very	O
similar	O
(	O
with	O
a	O
few	O
obsolete	O
ZX81	O
routines	O
left	O
in	O
the	O
Spectrum	O
ROM	B-Device
)	O
.	O
</s>
<s>
The	O
central	O
ULA	O
integrated	O
circuit	O
was	O
somewhat	O
similar	O
although	O
it	O
implemented	O
the	O
major	O
enhancement	O
over	O
the	O
ZX81	O
:	O
A	O
(	O
fully	O
)	O
hardware	B-Architecture
based	O
television	O
raster	O
generator	O
(	O
with	O
colour	O
)	O
that	O
indirectly	O
gave	O
the	O
new	O
machine	O
approximately	O
four	O
times	O
as	O
much	O
processing	O
power	O
as	O
the	O
ZX81	O
,	O
simply	O
due	O
to	O
the	O
Z80	B-General_Concept
now	O
being	O
released	O
from	O
this	O
video	O
generation	O
task	O
.	O
</s>
<s>
A	O
bug	O
in	O
the	O
ULA	O
as	O
originally	O
designed	O
meant	O
that	O
the	O
keyboard	O
did	O
not	O
always	O
scan	O
correctly	O
,	O
and	O
was	O
rectified	O
by	O
a	O
"	O
dead	O
cockroach	O
"	O
(	O
a	O
small	O
circuit	O
board	O
mounted	O
upside	O
down	O
next	O
to	O
the	O
CPU	B-General_Concept
)	O
for	O
Issue	O
1	O
ZX	B-Operating_System
Spectrums	I-Operating_System
.	O
</s>
<s>
The	O
original	O
ZX	B-Operating_System
Spectrum	I-Operating_System
is	O
remembered	O
for	O
its	O
rubber	O
chiclet	B-Device
keyboard	I-Device
,	O
diminutive	O
size	O
and	O
distinctive	O
rainbow	O
motif	O
.	O
</s>
<s>
It	O
was	O
originally	O
released	O
on	O
23	O
April	O
1982	O
with	O
16KB	O
of	O
RAM	B-Architecture
for	O
or	O
with	O
48KB	O
for	O
;	O
these	O
prices	O
were	O
reduced	O
to	O
and	O
respectively	O
in	O
1983	O
.	O
</s>
<s>
Owners	O
of	O
the	O
16KB	O
model	O
could	O
purchase	O
an	O
internal	O
32KB	O
RAM	B-Architecture
upgrade	O
,	O
which	O
for	O
early	O
"	O
Issue	O
1	O
"	O
machines	O
consisted	O
of	O
a	O
daughterboard	O
.	O
</s>
<s>
Later	O
issue	O
machines	O
required	O
the	O
fitting	O
of	O
8	O
dynamic	O
RAM	B-Architecture
chips	I-Architecture
and	O
a	O
few	O
TTL	B-General_Concept
chips	O
.	O
</s>
<s>
External	O
32KB	O
RAM	B-Architecture
packs	O
that	O
mounted	O
in	O
the	O
rear	O
expansion	B-Device
slot	I-Device
were	O
available	O
from	O
third	O
parties	O
.	O
</s>
<s>
Both	O
machines	O
had	O
16KB	O
of	O
onboard	O
ROM	B-Device
.	O
</s>
<s>
An	O
"	O
Issue	O
1	O
"	O
ZX	B-Operating_System
Spectrum	I-Operating_System
can	O
be	O
distinguished	O
from	O
later	O
models	O
by	O
the	O
colour	O
of	O
the	O
keys	O
–	O
light	O
grey	O
for	O
Issue	O
1	O
,	O
blue-grey	O
for	O
later	O
machines	O
.	O
</s>
<s>
An	O
online	O
tool	O
now	O
exists	O
to	O
allow	O
users	O
to	O
ascertain	O
the	O
likely	O
issue	O
number	O
of	O
their	O
ZX	B-Operating_System
Spectrum	I-Operating_System
by	O
inputting	O
the	O
serial	O
number	O
.	O
</s>
<s>
An	O
external	O
tape	O
recorder	O
was	O
needed	O
to	O
load	O
the	O
majority	O
of	O
software	O
released	O
,	O
or	O
the	O
ZX	B-Device
Microdrive	I-Device
.	O
</s>
<s>
The	O
original	O
ZX	B-Operating_System
Spectrum	I-Operating_System
model	O
experienced	O
numerous	O
changes	O
to	O
its	O
motherboard	O
design	O
;	O
mainly	O
to	O
improve	O
manufacturing	O
efficiencies	O
,	O
but	O
also	O
to	O
correct	O
bugs	O
from	O
previous	O
boards	O
.	O
</s>
<s>
This	O
48KB	O
Spectrum	O
(	O
development	O
code-name	O
TB	O
)	O
introduced	O
a	O
new	O
QL-style	O
case	O
with	O
an	O
injection-moulded	O
keyboard	O
and	O
a	O
reset	O
button	O
that	O
was	O
basically	O
a	O
switch	O
that	O
shorted	O
across	O
the	O
CPU	B-General_Concept
reset	O
capacitor	O
.	O
</s>
<s>
In	O
1985	O
,	O
Sinclair	O
developed	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
128	O
(	O
code-named	O
Derby	O
)	O
in	O
conjunction	O
with	O
their	O
Spanish	O
distributor	O
Investrónica	O
(	O
a	O
subsidiary	O
of	O
El	O
Corte	O
Inglés	O
department	O
store	O
group	O
)	O
.	O
</s>
<s>
Investrónica	O
had	O
helped	O
adapt	O
the	O
ZX	O
Spectrum+	O
to	O
the	O
Spanish	O
market	O
after	O
the	O
Spanish	O
government	O
introduced	O
a	O
special	O
tax	O
on	O
all	O
computers	O
with	O
64KB	O
RAM	B-Architecture
or	O
less	O
,	O
and	O
a	O
law	O
which	O
obliged	O
all	O
computers	O
sold	O
in	O
Spain	O
to	O
support	O
the	O
Spanish	O
alphabet	O
and	O
show	O
messages	O
in	O
Spanish	O
.	O
</s>
<s>
The	O
appearance	O
of	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
128	O
was	O
similar	O
to	O
the	O
ZX	O
Spectrum+	O
,	O
with	O
the	O
exception	O
of	O
a	O
large	O
external	O
heatsink	O
for	O
the	O
internal	O
7805	O
voltage	O
regulator	O
added	O
to	O
the	O
right	O
hand	O
end	O
of	O
the	O
case	O
,	O
replacing	O
the	O
internal	O
heatsink	O
in	O
previous	O
versions	O
.	O
</s>
<s>
New	O
features	O
included	O
128KB	O
RAM	B-Architecture
with	O
RAM	B-Architecture
disc	O
commands	O
'	O
save	O
!	O
</s>
<s>
"	O
name	O
"	O
 '	O
,	O
three-channel	O
audio	O
via	O
the	O
AY-3-8912	B-Device
chip	O
,	O
MIDI	O
compatibility	O
,	O
an	O
RS-232	O
serial	O
port	O
,	O
an	O
RGB	O
monitor	O
port	O
,	O
32KB	O
of	O
ROM	B-Device
including	O
an	O
improved	O
BASIC	O
editor	O
,	O
and	O
an	O
external	O
keypad	O
.	O
</s>
<s>
No	O
external	O
keypad	O
was	O
available	O
for	O
the	O
UK	O
release	O
,	O
although	O
the	O
ROM	B-Device
routines	O
to	O
use	O
it	O
and	O
the	O
port	O
itself	O
remained	O
.	O
</s>
<s>
The	O
Z80	B-General_Concept
processor	O
used	O
in	O
the	O
Spectrum	O
has	O
a	O
16-bit	O
address	O
bus	B-General_Concept
,	O
which	O
means	O
only	O
64KB	O
of	O
memory	O
can	O
be	O
directly	O
addressed	O
.	O
</s>
<s>
To	O
facilitate	O
the	O
extra	O
80KB	O
of	O
RAM	B-Architecture
the	O
designers	O
used	O
bank	B-General_Concept
switching	I-General_Concept
so	O
the	O
new	O
memory	O
would	O
be	O
available	O
as	O
eight	O
pages	O
of	O
16KB	O
at	O
the	O
top	O
of	O
the	O
address	O
space	O
.	O
</s>
<s>
The	O
same	O
technique	O
was	O
used	O
to	O
page	O
between	O
the	O
new	O
16KB	O
editor	O
ROM	B-Device
and	O
the	O
original	O
16KB	O
BASIC	O
ROM	B-Device
at	O
the	O
bottom	O
of	O
the	O
address	O
space	O
.	O
</s>
<s>
To	O
enable	O
BASIC	O
programmers	O
to	O
access	O
the	O
additional	O
memory	O
,	O
a	O
RAM	B-Architecture
disk	O
was	O
created	O
where	O
files	O
could	O
be	O
stored	O
in	O
the	O
additional	O
80KB	O
of	O
RAM	B-Architecture
.	O
</s>
<s>
The	O
ZX	B-Operating_System
Spectrum	I-Operating_System
128	O
had	O
no	O
internal	O
speaker	O
,	O
unlike	O
its	O
predecessors	O
.	O
</s>
<s>
The	O
ZX	B-Operating_System
Spectrum	I-Operating_System
+2	O
was	O
Amstrad	O
's	O
first	O
Spectrum	O
,	O
coming	O
shortly	O
after	O
their	O
purchase	O
of	O
the	O
Spectrum	O
range	O
and	O
"	O
Sinclair	O
"	O
brand	O
in	O
1986	O
.	O
</s>
<s>
The	O
machine	O
featured	O
an	O
all-new	O
grey	O
case	O
featuring	O
a	O
spring-loaded	O
keyboard	O
,	O
dual	O
joystick	B-Device
ports	O
,	O
and	O
a	O
built-in	O
cassette	O
recorder	O
dubbed	O
the	O
"	O
Datacorder	O
"	O
(	O
like	O
the	O
Amstrad	B-Device
CPC	I-Device
464	I-Device
)	O
,	O
but	O
was	O
in	O
most	O
respects	O
identical	O
to	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
128	O
.	O
</s>
<s>
The	O
main	O
menu	O
screen	O
lacked	O
the	O
Spectrum	O
128	O
's	O
"	O
Tape	O
Test	O
"	O
option	O
,	O
and	O
the	O
ROM	B-Device
was	O
altered	O
to	O
account	O
for	O
a	O
new	O
1986	O
Amstrad	O
copyright	O
message	O
.	O
</s>
<s>
Instead	O
,	O
the	O
+2	O
boasted	O
a	O
menu	O
system	O
,	O
almost	O
identical	O
to	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
128	O
,	O
where	O
one	O
could	O
switch	O
between	O
48K	O
BASIC	O
programming	O
with	O
the	O
keywords	O
,	O
and	O
128K	O
BASIC	O
programming	O
in	O
which	O
all	O
words	O
(	O
keywords	O
and	O
otherwise	O
)	O
must	O
be	O
typed	O
out	O
in	O
full	O
(	O
although	O
the	O
keywords	O
are	O
still	O
stored	O
internally	O
as	O
one	O
character	O
each	O
)	O
.	O
</s>
<s>
The	O
ZX	B-Operating_System
Spectrum	I-Operating_System
+2	O
power	O
supply	O
was	O
a	O
grey	O
version	O
of	O
the	O
ZX	O
Spectrum+	O
and	O
128	O
power	O
supply	O
.	O
</s>
<s>
The	O
ZX	B-Operating_System
Spectrum	I-Operating_System
+3	O
,	O
released	O
in	O
1987	O
,	O
looked	O
similar	O
to	O
the	O
+2A	O
but	O
featured	O
a	O
built-in	O
3-inch	B-Operating_System
floppy	I-Operating_System
disk	I-Operating_System
drive	O
(	O
like	O
the	O
Amstrad	B-Device
CPC	I-Device
6128	I-Device
)	O
instead	O
of	O
the	O
tape	O
drive	O
,	O
and	O
was	O
in	O
a	O
black	O
case	O
.	O
</s>
<s>
It	O
was	O
launched	O
in	O
1987	O
,	O
initially	O
retailed	O
for	O
£249	O
and	O
then	O
later	O
£199	O
and	O
was	O
the	O
only	O
Spectrum	O
capable	O
of	O
running	O
the	O
CP/M	B-Application
operating	I-Application
system	I-Application
without	O
additional	O
hardware	B-Architecture
.	O
</s>
<s>
One	O
was	O
home	O
to	O
the	O
second	O
part	O
of	O
the	O
reorganised	O
128	O
ROM	B-Device
and	O
the	O
other	O
hosted	O
the	O
3	O
's	O
disk	O
operating	O
system	O
.	O
</s>
<s>
This	O
was	O
a	O
modified	O
version	O
of	O
Amstrad	O
's	O
PCWDOS	O
(	O
the	O
disk	O
access	O
code	O
used	O
in	O
LocoScript	B-Protocol
)	O
,	O
called	O
+3DOS	B-Operating_System
.	O
</s>
<s>
To	O
be	O
able	O
to	O
run	O
CP/M	B-Application
,	O
which	O
requires	O
RAM	B-Architecture
at	O
the	O
bottom	O
of	O
the	O
address	O
space	O
,	O
the	O
bank-switching	B-General_Concept
was	O
further	O
improved	O
,	O
allowing	O
the	O
ROM	B-Device
to	O
be	O
paged	O
out	O
for	O
another	O
16KB	O
of	O
RAM	B-Architecture
.	O
</s>
<s>
Removal	O
of	O
several	O
lines	O
on	O
the	O
expansion	B-Device
bus	I-Device
edge	O
connector	O
(	O
video	O
,	O
power	O
,	O
and	O
IORQGE	O
)	O
;	O
caused	O
many	O
external	O
devices	O
problems	O
;	O
some	O
such	O
as	O
the	O
VTX5000	O
modem	B-Application
could	O
be	O
used	O
via	O
the	O
"	O
FixIt	O
"	O
device	O
.	O
</s>
<s>
Reading	O
a	O
non-existent	O
I/O	O
port	O
no	O
longer	O
returned	O
the	O
last	O
attribute	O
;	O
caused	O
certain	O
games	O
such	O
as	O
Arkanoid	B-Device
to	O
be	O
unplayable	O
.	O
</s>
<s>
Memory	O
timing	O
changes	O
;	O
certain	O
RAM	B-Architecture
banks	O
were	O
now	O
contended	O
causing	O
high-speed	O
colour-changing	O
effects	O
to	O
fail	O
.	O
</s>
<s>
The	O
keypad	O
scanning	O
routines	O
from	O
the	O
ROM	B-Device
were	O
removed	O
.	O
</s>
<s>
The	O
ZX	B-Device
Interface	I-Device
1	I-Device
was	O
incompatible	O
due	O
to	O
differences	O
in	O
ROM	B-Device
and	O
expansion	O
connector	O
,	O
making	O
it	O
impossible	O
to	O
connect	O
and	O
use	O
the	O
Microdrive	O
units	O
.	O
</s>
<s>
Unlike	O
previous	O
models	O
,	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
+3	O
power	O
supply	O
uses	O
a	O
DIN	O
connector	O
and	O
has	O
"	O
Sinclair	O
+3	O
"	O
written	O
on	O
the	O
case	O
.	O
</s>
<s>
At	O
the	O
time	O
,	O
it	O
was	O
estimated	O
about	O
15%	O
of	O
ZX	B-Operating_System
Spectrums	I-Operating_System
sold	O
had	O
been	O
+3	O
models	O
.	O
</s>
<s>
The	O
ZX	B-Operating_System
Spectrum	I-Operating_System
+2A	O
was	O
a	O
new	O
version	O
of	O
the	O
Spectrum	O
+2	O
using	O
the	O
same	O
circuit	O
board	O
as	O
the	O
Spectrum	O
+3	O
.	O
</s>
<s>
The	O
Spectrum	O
+	O
2A/	O
+3	O
motherboard	O
(	O
AMSTRAD	O
part	O
number	O
Z70830	O
)	O
was	O
designed	O
so	O
that	O
it	O
could	O
be	O
assembled	O
with	O
a	O
+2	O
style	O
"	O
datacorder	O
"	O
connected	O
instead	O
of	O
the	O
floppy	B-Device
disk	I-Device
controller	I-Device
.	O
</s>
<s>
The	O
power	O
supply	O
of	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
+2A	O
used	O
the	O
same	O
pinout	B-Application
as	O
the	O
+3	O
and	O
has	O
"	O
Sinclair	O
+2	O
"	O
written	O
on	O
the	O
case	O
.	O
</s>
<s>
The	O
ZX	B-Operating_System
Spectrum	I-Operating_System
+2B	O
and	O
ZX	B-Operating_System
Spectrum	I-Operating_System
+3B	O
were	O
functionally	O
similar	O
in	O
design	O
to	O
the	O
Spectrum	O
+2A	O
and	O
+3	O
.	O
</s>
<s>
The	O
+2B	O
board	O
(	O
AMSTRAD	O
part	O
number	O
Z70833	O
)	O
has	O
no	O
provision	O
for	O
floppy	B-Device
disk	I-Device
controller	I-Device
circuitry	O
and	O
the	O
+3B	O
motherboard	O
(	O
Amstrad	O
part	O
number	O
Z70835	O
)	O
has	O
no	O
provision	O
for	O
connecting	O
an	O
internal	O
tape	O
drive	O
.	O
</s>
<s>
An	O
enhanced	O
version	O
of	O
the	O
original	O
Spectrum	O
,	O
with	O
better	O
sound	O
,	O
graphics	O
and	O
other	O
modifications	O
was	O
marketed	O
in	O
the	O
US	O
by	O
Timex	O
as	O
the	O
Timex	B-Device
Sinclair	I-Device
2068	I-Device
.	O
</s>
<s>
A	O
case	O
in	O
point	O
was	O
the	O
abortive	O
Pandora	O
portable	O
Spectrum	O
,	O
whose	O
ULA	O
had	O
the	O
high	B-Algorithm
resolution	I-Algorithm
video	O
mode	O
pioneered	O
in	O
the	O
T/S	B-Device
2068	I-Device
.	O
</s>
<s>
After	O
Amstrad	O
bought	O
the	O
computer	O
business	O
of	O
Sinclair	O
Research	O
,	O
Sir	O
Clive	O
retained	O
the	O
rights	O
to	O
the	O
Pandora	O
project	O
,	O
and	O
it	O
evolved	O
into	O
the	O
Cambridge	B-Device
Computer	I-Device
Z88	I-Device
,	O
launched	O
in	O
1987	O
.	O
</s>
<s>
Starting	O
in	O
1984	O
,	O
Timex	O
of	O
Portugal	O
developed	O
and	O
produced	O
several	O
Timex	O
branded	O
computers	O
,	O
including	O
the	O
Timex	B-Device
Computer	I-Device
2048	I-Device
,	O
highly	O
compatible	O
with	O
the	O
Sinclair	B-Operating_System
ZX	I-Operating_System
Spectrum	I-Operating_System
48K	I-Operating_System
,	O
which	O
was	O
very	O
successful	O
in	O
both	O
Portugal	O
and	O
Poland	O
.	O
</s>
<s>
Timex	O
of	O
Portugal	O
also	O
made	O
a	O
PAL	B-Language
version	O
of	O
the	O
T/S	B-Device
2068	I-Device
,	O
called	O
the	O
Timex	B-Device
Computer	I-Device
2068	I-Device
(	O
or	O
TC	B-Device
2068	I-Device
for	O
short	O
)	O
which	O
had	O
different	O
buffers	O
for	O
both	O
the	O
ULA	O
and	O
the	O
CPU	B-General_Concept
,	O
which	O
significantly	O
increased	O
the	O
compatibility	O
with	O
ZX	B-Operating_System
Spectrum	I-Operating_System
software	O
when	O
compared	O
to	O
the	O
North	O
American	O
model	O
(	O
the	O
T/S	B-Device
2068	I-Device
)	O
.	O
</s>
<s>
The	O
expansion	B-Device
port	I-Device
was	O
also	O
modified	O
and	O
made	O
to	O
be	O
100%	O
compatible	O
with	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
's	O
,	O
which	O
bypassed	O
the	O
need	O
for	O
a	O
"	O
Twister	O
Board	O
"	O
expansion	O
that	O
the	O
T/S	B-Device
2068	I-Device
needed	O
to	O
make	O
it	O
compatible	O
with	O
ZX	B-Operating_System
Spectrum	I-Operating_System
expansion	O
hardware	B-Architecture
.	O
</s>
<s>
The	O
software	O
developed	O
for	O
the	O
TC	B-Device
2068	I-Device
is	O
completely	O
compatible	O
with	O
the	O
T/S	B-Device
2068	I-Device
,	O
since	O
the	O
ROMs	O
were	O
n't	O
altered	O
.	O
</s>
<s>
Timex	O
of	O
Portugal	O
also	O
developed	O
a	O
ZX	B-Operating_System
Spectrum	I-Operating_System
"	O
emulator	B-Application
"	O
on	O
cartridge	B-Protocol
form	O
that	O
mapped	O
the	O
first	O
16KB	O
exactly	O
like	O
the	O
earlier	O
TC	B-Device
2048	I-Device
computer	O
did	O
.	O
</s>
<s>
Several	O
other	O
upgrades	O
were	O
made	O
available	O
,	O
including	O
a	O
BASIC64	O
cartridge	B-Protocol
that	O
enabled	O
the	O
TC	B-Device
2068	I-Device
to	O
use	O
high	B-Algorithm
resolution	I-Algorithm
(	O
512x192	O
)	O
modes	O
.	O
</s>
<s>
Despite	O
having	O
an	O
AY-3-8912	B-Device
sound	O
chip	O
,	O
it	O
's	O
not	O
connected	O
in	O
the	O
same	O
ports	O
as	O
in	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
128K	O
,	O
rendering	O
the	O
TC	B-Device
2048	I-Device
incompatible	O
with	O
the	O
AY	O
sound	O
that	O
the	O
Spectrum	O
128K	O
games	O
produced	O
.	O
</s>
<s>
Due	O
to	O
all	O
its	O
advantages	O
compared	O
to	O
the	O
usual	O
T/S	B-Device
2068	I-Device
,	O
a	O
North	O
American	O
company	O
,	O
Zebra	O
Systems	O
,	O
licensed	O
the	O
Timex	O
TC	B-Device
2068	I-Device
and	O
sold	O
it	O
in	O
the	O
United	O
States	O
as	O
the	O
Zebra	O
Silver	O
Avenger	O
.	O
</s>
<s>
They	O
also	O
sold	O
the	O
FDD	B-Device
3000	I-Device
as	O
the	O
Zebra	O
FDD	B-Device
3000	I-Device
in	O
a	O
silver	O
case	O
(	O
as	O
opposed	O
to	O
the	O
European	O
black	O
cases	O
)	O
to	O
match	O
their	O
colour	O
scheme	O
.	O
</s>
<s>
Timex	O
of	O
Portugal	O
was	O
working	O
on	O
a	O
successor	O
to	O
the	O
TC	B-Device
2068	I-Device
called	O
the	O
TC	B-Device
3256	I-Device
,	O
using	O
a	O
Z80A	B-General_Concept
CPU	B-General_Concept
and	O
featuring	O
256KB	O
of	O
RAM	B-Architecture
,	O
which	O
would	O
feature	O
a	O
ZX	B-Operating_System
Spectrum	I-Operating_System
BASIC	O
operating	O
mode	O
and	O
a	O
CP/M	B-Application
operating	O
mode	O
,	O
but	O
the	O
company	O
pulled	O
the	O
plug	O
on	O
its	O
development	O
as	O
the	O
8-bit	O
market	O
was	O
no	O
longer	O
profitable	O
by	O
the	O
end	O
of	O
1989	O
.	O
</s>
<s>
Only	O
one	O
complete	O
and	O
fully	O
working	O
prototype	O
of	O
the	O
TC	B-Device
3256	I-Device
was	O
made	O
.	O
</s>
<s>
Numerous	O
unofficial	B-Architecture
Spectrum	I-Architecture
clones	I-Architecture
were	O
produced	O
,	O
especially	O
in	O
the	O
Eastern	O
and	O
Central	O
European	O
countries	O
(	O
e.g.	O
</s>
<s>
in	O
USSR	O
(	O
called	O
)	O
,	O
Romania	O
,	O
and	O
Czechoslovakia	O
)	O
where	O
several	O
models	O
were	O
produced	O
(	O
such	O
as	O
the	O
Tim-S	O
,	O
HC85	O
,	O
HC91	O
,	O
Cobra	O
,	O
Junior	O
,	O
CIP	O
,	O
CIP	O
3	O
,	O
Jet	O
,	O
Didaktik	O
Gama	O
)	O
,	O
some	O
featuring	O
CP/M	B-Application
and	O
a	O
5.25	B-Device
"	I-Device
/3.5	O
"	O
floppy	O
disk	O
.	O
</s>
<s>
Microdigital	O
TK90X	B-Device
and	O
TK95	B-Device
,	O
made	O
in	O
Brazil	O
and	O
the	O
Czerweny	O
CZ	O
,	O
made	O
in	O
Argentina	O
)	O
.	O
</s>
<s>
In	O
the	O
Soviet	O
Union	O
,	O
ZX	B-Operating_System
Spectrum	I-Operating_System
clones	O
were	O
assembled	O
by	O
thousands	O
of	O
small	O
start-ups	O
and	O
distributed	O
through	O
poster	O
ads	O
and	O
street	O
stalls	O
.	O
</s>
<s>
Some	O
of	O
them	O
are	O
still	O
being	O
produced	O
,	O
such	O
as	O
the	O
Pentagon	B-Device
and	O
ATM	B-Device
Turbo	I-Device
.	O
</s>
<s>
In	O
the	O
UK	O
,	O
Spectrum	O
peripheral	O
vendor	O
Miles	O
Gordon	O
Technology	O
(	O
MGT	O
)	O
released	O
the	O
SAM	B-Device
Coupé	I-Device
as	O
a	O
potential	O
successor	O
with	O
some	O
Spectrum	O
compatibility	O
.	O
</s>
<s>
By	O
this	O
point	O
,	O
the	O
Amiga	B-Device
and	O
Atari	B-Device
ST	I-Device
had	O
taken	O
hold	O
of	O
the	O
market	O
,	O
leaving	O
MGT	O
in	O
eventual	O
receivership	O
.	O
</s>
<s>
In	O
2013	O
,	O
an	O
FPGA-based	O
redesign	O
of	O
the	O
original	O
ZX	B-Operating_System
Spectrum	I-Operating_System
known	O
as	O
the	O
ZX	O
Uno	O
,	O
was	O
formally	O
announced	O
.	O
</s>
<s>
All	O
of	O
its	O
hardware	B-Architecture
,	O
firmware	O
and	O
software	O
are	O
open	O
source	O
,	O
released	O
as	O
Creative	O
Commons	O
license	O
Share-alike	O
.	O
</s>
<s>
The	O
use	O
of	O
a	O
Spartan	O
FPGA	B-Architecture
allows	O
the	O
system	O
to	O
not	O
only	O
re-implement	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
,	O
but	O
many	O
other	O
8	O
bit	O
computers	O
and	O
games	O
consoles	O
The	O
device	O
can	O
also	O
run	O
modern	O
open	O
FPGA	B-Architecture
machines	O
such	O
as	O
the	O
Chloe	O
280SE	O
.	O
</s>
<s>
In	O
January	O
2014	O
,	O
Elite	B-Application
Systems	O
,	O
who	O
produced	O
a	O
successful	O
range	O
of	O
software	O
for	O
the	O
original	O
ZX	B-Operating_System
Spectrum	I-Operating_System
in	O
the	O
1980s	O
,	O
announced	O
plans	O
for	O
a	O
Spectrum-themed	O
bluetooth	B-Protocol
keyboard	O
that	O
would	O
attach	O
to	O
mobile	O
devices	O
.	O
</s>
<s>
The	O
company	O
used	O
a	O
crowdfunding	O
campaign	O
to	O
fund	O
the	O
Recreated	O
ZX	B-Operating_System
Spectrum	I-Operating_System
,	O
which	O
would	O
be	O
compatible	O
with	O
games	O
the	O
company	O
had	O
already	O
released	O
on	O
iTunes	B-Operating_System
and	O
Google	B-Application
Play	I-Application
.	O
</s>
<s>
Elite	B-Application
Systems	O
took	O
down	O
its	O
Spectrum	O
Collection	O
application	O
the	O
following	O
month	O
,	O
due	O
to	O
complaints	O
from	O
authors	O
of	O
the	O
original	O
1980	O
's	O
game	O
software	O
that	O
they	O
had	O
not	O
been	O
paid	O
for	O
the	O
content	O
.	O
</s>
<s>
Wired	O
described	O
the	O
finished	O
device	O
,	O
which	O
was	O
styled	O
as	O
an	O
original	O
Spectrum	B-Operating_System
48k	I-Operating_System
keyboard	O
,	O
as	O
"	O
absolutely	O
gorgeous	O
"	O
but	O
said	O
it	O
was	O
ultimately	O
more	O
of	O
an	O
expensive	O
novelty	O
than	O
an	O
actual	O
Spectrum	O
.	O
</s>
<s>
In	O
July	O
2019	O
,	O
Eurogamer	O
reported	O
that	O
many	O
of	O
the	O
orders	O
had	O
yet	O
to	O
be	O
delivered	O
due	O
to	O
a	O
dispute	O
between	O
Elite	B-Application
Systems	O
and	O
their	O
manufacturer	O
,	O
Eurotech	O
.	O
</s>
<s>
Later	O
in	O
2014	O
,	O
the	O
Sinclair	B-Operating_System
ZX	I-Operating_System
Spectrum	I-Operating_System
Vega	O
retro	O
video	O
game	O
console	O
was	O
announced	O
by	O
Retro	O
Computers	O
Ltd	O
and	O
crowdfunded	O
on	O
Indiegogo	O
with	O
the	O
backing	O
of	O
Clive	O
Sinclair	O
.	O
</s>
<s>
The	O
Vega	O
,	O
released	O
in	O
2015	O
,	O
took	O
the	O
form	O
of	O
a	O
handheld	B-Device
TV	I-Device
game	I-Device
but	O
the	O
lack	O
of	O
a	O
full	O
keyboard	O
led	O
to	O
criticism	O
from	O
reviewers	O
due	O
to	O
the	O
large	O
number	O
of	O
text	O
adventures	O
supplied	O
with	O
the	O
device	O
.	O
</s>
<s>
The	O
follow-up	O
,	O
the	O
ZX	B-Device
Spectrum	I-Device
Vega+	I-Device
was	O
designed	O
as	O
a	O
handheld	B-Application
game	I-Application
console	I-Application
.	O
</s>
<s>
On	O
30	O
July	O
2018	O
,	O
Eurogamer	O
reported	O
that	O
one	O
backer	O
had	O
received	O
a	O
ZX	O
Vega+	B-Device
console	O
and	O
quoted	O
them	O
as	O
being	O
"	O
quite	O
disappointed	O
"	O
that	O
"	O
the	O
few	O
supplied	O
sample	O
games	O
do	O
n't	O
work	O
"	O
and	O
that	O
the	O
"	O
build	O
quality	O
's	O
not	O
the	O
greatest	O
"	O
.	O
</s>
<s>
Reviewing	O
the	O
Vega+	B-Device
,	O
The	O
Register	O
criticised	O
numerous	O
aspects	O
and	O
features	O
of	O
the	O
machine	O
,	O
including	O
its	O
design	O
and	O
build	O
quality	O
and	O
summed	O
up	O
by	O
saying	O
that	O
the	O
"	O
entire	O
feel	O
is	O
plasticky	O
and	O
inconsequential	O
"	O
.	O
</s>
<s>
The	O
ZX	B-Device
Spectrum	I-Device
Next	I-Device
(	O
not	O
to	O
be	O
confused	O
with	O
the	O
older	O
,	O
two-processor	O
ZX	O
Next	O
)	O
is	O
an	O
expanded	O
and	O
updated	O
version	O
of	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
computer	O
implemented	O
with	O
FPGA	B-Architecture
technology	O
funded	O
by	O
a	O
Kickstarter	O
campaign	O
in	O
April	O
2017	O
,	O
with	O
the	O
board-only	O
computer	O
delivered	O
to	O
backers	O
later	O
that	O
year	O
.	O
</s>
<s>
A	O
further	O
Kickstarter	O
for	O
an	O
improved	O
revision	O
of	O
the	O
hardware	B-Architecture
was	O
funded	O
in	O
August	O
2020	O
.	O
</s>
<s>
Several	O
peripherals	O
were	O
marketed	O
by	O
Sinclair	O
:	O
the	O
ZX	O
Printer	O
was	O
already	O
on	O
the	O
market	O
,	O
as	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
expansion	B-Device
bus	I-Device
was	O
partially	O
backwards-compatible	B-General_Concept
with	O
that	O
of	O
the	O
ZX81	O
.	O
</s>
<s>
The	O
ZX	B-Device
Interface	I-Device
1	I-Device
add-on	O
module	O
included	O
8KB	O
of	O
ROM	B-Device
,	O
an	O
RS-232	O
serial	O
port	O
,	O
a	O
proprietary	O
LAN	B-General_Concept
interface	O
(	O
called	O
ZX	O
Net	O
)	O
,	O
and	O
an	O
interface	O
for	O
the	O
connection	O
of	O
up	O
to	O
eight	O
ZX	B-Device
Microdrives	I-Device
–	O
somewhat	O
unreliable	O
but	O
speedy	O
tape-loop	O
cartridge	B-Protocol
storage	O
devices	O
released	O
in	O
July	O
1983	O
.	O
</s>
<s>
These	O
were	O
used	O
in	O
a	O
revised	O
version	O
on	O
the	O
Sinclair	B-Device
QL	I-Device
,	O
whose	O
storage	O
format	O
was	O
electrically	O
compatible	O
but	O
logically	O
incompatible	O
with	O
the	O
Spectrum	O
's	O
.	O
</s>
<s>
Sinclair	O
also	O
released	O
the	O
ZX	B-Device
Interface	I-Device
2	I-Device
which	O
added	O
two	O
joystick	B-Device
ports	O
and	O
a	O
ROM	B-Protocol
cartridge	I-Protocol
port	O
.	O
</s>
<s>
There	O
were	O
a	O
plethora	O
of	O
third-party	O
hardware	B-Architecture
addons	O
.	O
</s>
<s>
The	O
better	O
known	O
of	O
these	O
included	O
the	O
Kempston	B-Device
joystick	B-Device
interface	O
,	O
the	O
Morex	O
Peripherals	O
Centronics/RS	O
-232	O
interface	O
,	O
the	O
Currah	B-Application
Microspeech	O
unit	O
(	O
speech	O
synthesis	O
)	O
,	O
Videoface	B-Device
Digitiser	O
,	O
RAM	B-Architecture
pack	O
,	O
the	O
Cheetah	O
Marketing	O
SpecDrum	O
,	O
a	O
drum	O
machine	O
,	O
and	O
the	O
Multiface	B-Device
,	O
a	O
snapshot	O
and	O
disassembly	O
tool	O
from	O
Romantic	O
Robot	O
.	O
</s>
<s>
There	O
were	O
disk	O
drive	O
interfaces	O
,	O
such	O
as	O
the	O
Abbeydale	O
Designers/Watford	O
Electronics	O
SPDOS	O
,	O
Abbeydale	O
Designers/Kempston	O
KDOS	O
and	O
Opus	O
Discovery	O
.	O
</s>
<s>
The	O
SPDOS	O
and	O
KDOS	O
interfaces	O
were	O
the	O
first	O
to	O
come	O
bundled	O
with	O
office	O
productivity	O
software	O
(	O
Tasword	B-Protocol
Word	B-General_Concept
Processor	I-General_Concept
,	O
Masterfile	O
database	O
and	O
Omnicalc	O
spreadsheet	B-Application
)	O
.	O
</s>
<s>
The	O
most	O
popular	O
floppy	B-Device
disk	I-Device
systems	O
(	O
except	O
in	O
East	O
Europe	O
)	O
were	O
the	O
DISCiPLE	B-Device
and	O
+D	B-Device
systems	O
released	O
by	O
Miles	O
Gordon	O
Technology	O
in	O
1987	O
and	O
1988	O
respectively	O
.	O
</s>
<s>
During	O
the	O
mid-1980s	O
,	O
Telemap	O
Group	O
Ltd	O
launched	O
a	O
fee-based	O
service	O
allowing	O
users	O
to	O
connect	O
their	O
ZX	B-Operating_System
Spectrums	I-Operating_System
via	O
a	O
Prism	O
Micro	O
Products	O
VTX5000	O
modem	B-Application
to	O
a	O
viewdata	B-Application
service	O
known	O
as	O
Micronet	O
800	O
,	O
hosted	O
by	O
Prestel	B-General_Concept
,	O
which	O
provided	O
news	O
and	O
information	O
about	O
microcomputers	B-Architecture
.	O
</s>
<s>
The	O
service	O
allowed	O
a	O
form	O
of	O
instant	B-Application
messaging	I-Application
and	O
online	O
shopping	O
.	O
</s>
<s>
While	O
games	O
comprised	O
the	O
majority	O
of	O
commercial	O
ZX	B-Operating_System
Spectrum	I-Operating_System
software	O
,	O
there	O
were	O
also	O
programming	O
language	O
implementations	O
,	O
databases	O
(	O
e.g.	O
</s>
<s>
VU-File	O
)	O
,	O
word	B-General_Concept
processors	I-General_Concept
(	O
e.g.	O
</s>
<s>
TaswordII	O
)	O
,	O
spreadsheets	B-Application
(	O
e.g.	O
</s>
<s>
OCP	B-Application
Art	I-Application
Studio	I-Application
)	O
,	O
and	O
even	O
3D-modelling	O
(	O
e.g.	O
</s>
<s>
The	O
early	O
Spectrum	O
models	O
 '	O
great	O
success	O
as	O
a	O
games	O
platform	O
came	O
in	O
spite	O
of	O
its	O
lack	O
of	O
built-in	O
joystick	B-Device
ports	O
,	O
primitive	O
sound	O
generation	O
,	O
and	O
colour	O
support	O
that	O
was	O
optimised	O
for	O
text	O
display	O
:	O
the	O
hardware	B-Architecture
limitations	O
of	O
the	O
platform	O
required	O
a	O
particular	O
level	O
of	O
creativity	O
from	O
video	O
game	O
designers	O
.	O
</s>
<s>
From	O
August	O
1982	O
,	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
came	O
bundled	O
with	O
a	O
software	O
starter	O
pack	O
in	O
the	O
form	O
of	O
a	O
cassette	B-Device
tape	I-Device
entitled	O
Horizons	B-Application
:	I-Application
Software	I-Application
Starter	I-Application
Pack	I-Application
,	O
which	O
included	O
8	O
programs	O
:	O
Thro	O
 '	O
the	O
Wall	O
(	O
a	O
Breakout	B-Application
clone	I-Application
)	O
,	O
Bubblesort	O
,	O
Evolution	O
(	O
an	O
ecosystem	O
of	O
foxes	O
and	O
rabbits	O
)	O
,	O
Life	O
(	O
an	O
implementation	O
of	O
Conway	O
's	O
Game	O
of	O
Life	O
)	O
,	O
Draw	O
(	O
a	O
basic	O
object-based	O
drawing	O
utility	O
)	O
,	O
Monte	O
Carlo	O
(	O
a	O
simulation	O
of	O
the	O
rolling	O
of	O
two	O
dice	O
)	O
,	O
Character	O
Generator	O
(	O
for	O
editing	O
user	O
defined	O
graphics	O
)	O
and	O
Beating	O
of	O
Waves	O
(	O
plots	O
the	O
sum	O
of	O
two	O
sine	O
waves	O
)	O
.	O
</s>
<s>
According	O
to	O
the	O
90th	O
issue	O
of	O
the	O
British	O
gaming	O
magazine	O
GamesMaster	O
,	O
the	O
ten	O
best	O
games	O
released	O
were	O
(	O
in	O
descending	O
order	O
)	O
Head	B-Application
Over	I-Application
Heels	I-Application
,	O
Jet	B-Application
Set	I-Application
Willy	I-Application
,	O
Skool	B-Application
Daze	I-Application
,	O
Renegade	B-Application
,	O
R-Type	B-Application
,	O
Knight	B-Application
Lore	I-Application
,	O
Dizzy	B-Application
,	O
The	B-Application
Hobbit	I-Application
,	O
The	B-Application
Way	I-Application
of	I-Application
the	I-Application
Exploding	I-Application
Fist	I-Application
,	O
and	O
Match	B-Application
Day	I-Application
II	I-Application
.	O
</s>
<s>
Most	O
Spectrum	O
software	O
was	O
originally	O
distributed	O
on	O
audio	B-Device
cassette	I-Device
tapes	I-Device
.	O
</s>
<s>
Although	O
the	O
ZX	B-Device
Microdrive	I-Device
was	O
initially	O
greeted	O
with	O
good	O
reviews	O
,	O
it	O
never	O
took	O
off	O
as	O
a	O
distribution	O
method	O
due	O
to	O
worries	O
about	O
the	O
quality	O
of	O
the	O
cartridges	B-Protocol
and	O
piracy	O
.	O
</s>
<s>
Hence	O
the	O
main	O
use	O
became	O
to	O
complement	O
tape	O
releases	O
,	O
usually	O
utilities	O
and	O
niche	O
products	O
like	O
the	O
Tasword	B-Protocol
word	B-General_Concept
processing	I-General_Concept
software	O
and	O
Trans	O
Express	O
,	O
(	O
a	O
tape	O
to	O
microdrive	O
copying	O
utility	O
)	O
.	O
</s>
<s>
Although	O
the	O
Interface	O
2	O
proved	O
popular	O
,	O
the	O
high	O
cost	O
of	O
ROM	B-Protocol
cartridges	I-Protocol
,	O
and	O
the	O
fact	O
that	O
they	O
were	O
limited	O
to	O
16K	O
in	O
size	O
,	O
meant	O
that	O
very	O
few	O
titles	O
were	O
released	O
in	O
this	O
format	O
.	O
</s>
<s>
Software	O
distributed	O
in	O
this	O
way	O
was	O
in	O
general	O
simpler	O
and	O
slower	O
than	O
its	O
assembly	B-Language
language	I-Language
counterparts	O
.	O
</s>
<s>
Another	O
software	O
distribution	O
method	O
was	O
to	O
broadcast	O
the	O
audio	O
stream	O
from	O
the	O
cassette	O
on	O
another	O
medium	O
and	O
have	O
users	O
record	O
it	O
onto	O
an	O
audio	B-Device
cassette	I-Device
themselves	O
.	O
</s>
<s>
In	O
radio	O
or	O
television	O
shows	O
in	O
many	O
European	O
countries	O
,	O
the	O
host	O
would	O
describe	O
a	O
program	O
,	O
instruct	O
the	O
audience	O
to	O
connect	O
a	O
cassette	B-Device
tape	I-Device
recorder	I-Device
to	O
the	O
radio	O
or	O
TV	O
and	O
then	O
broadcast	O
the	O
program	O
over	O
the	O
airwaves	O
in	O
audio	O
format	O
.	O
</s>
<s>
These	O
disks	O
were	O
known	O
under	O
various	O
trademarked	O
names	O
including	O
"	O
Floppy	B-Device
ROM	B-Device
"	O
,	O
"	O
Flexisoft	O
"	O
,	O
and	O
"	O
Discoflex	O
"	O
.	O
</s>
<s>
Many	O
copiers	O
—	O
utilities	O
to	O
copy	O
programs	O
from	O
audio	O
tape	O
to	O
another	O
tape	O
,	O
microdrive	O
tapes	O
,	O
and	O
later	O
on	O
diskettes	B-Device
—	O
were	O
available	O
for	O
the	O
Spectrum	O
.	O
</s>
<s>
As	O
a	O
response	O
to	O
this	O
,	O
publishers	O
introduced	O
copy	B-Application
protection	I-Application
measures	O
to	O
their	O
software	O
,	O
including	O
different	O
loading	O
schemes	O
.	O
</s>
<s>
Other	O
methods	O
for	O
copy	B-Application
prevention	I-Application
were	O
also	O
used	O
including	O
asking	O
for	O
a	O
particular	O
word	O
from	O
the	O
documentation	O
included	O
with	O
the	O
game	O
—	O
often	O
a	O
novella	O
such	O
as	O
the	O
Silicon	B-Application
Dreams	I-Application
trilogy	I-Application
—	O
or	O
another	O
physical	O
device	O
distributed	O
with	O
the	O
software	O
—	O
e.g.	O
</s>
<s>
Lenslok	B-Device
as	O
used	O
in	O
Elite	B-Application
,	O
or	O
the	O
colour-code	O
chart	O
included	O
with	O
Jet	B-Application
Set	I-Application
Willy	I-Application
.	O
</s>
<s>
Special	O
hardware	B-Architecture
,	O
such	O
as	O
Romantic	O
Robot	O
's	O
Multiface	B-Device
,	O
was	O
able	O
to	O
dump	O
a	O
copy	O
of	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
RAM	B-Architecture
to	O
disk/tape	O
at	O
the	O
press	O
of	O
a	O
button	O
,	O
entirely	O
circumventing	O
the	O
copy	B-Application
protection	I-Application
systems	O
.	O
</s>
<s>
One	O
popular	O
program	O
for	O
converting	O
Spectrum	O
files	O
from	O
tape	O
is	O
Taper	O
;	O
it	O
allows	O
connecting	O
a	O
cassette	B-Device
tape	I-Device
player	O
to	O
the	O
line	O
in	O
port	O
of	O
a	O
sound	B-Device
card	I-Device
,	O
or	O
—	O
through	O
a	O
simple	O
home-built	O
device	O
—	O
to	O
the	O
parallel	B-Device
port	I-Device
of	O
a	O
PC	O
.	O
</s>
<s>
Once	O
in	O
files	O
on	O
a	O
host	O
machine	O
,	O
the	O
software	O
can	O
be	O
executed	O
on	O
an	O
emulator	B-Application
.	O
</s>
<s>
The	O
ZX	B-Operating_System
Spectrum	I-Operating_System
enjoyed	O
a	O
very	O
strong	O
community	O
early	O
on	O
.	O
</s>
<s>
Several	O
other	O
contemporary	O
computer	O
magazines	O
covered	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
as	O
part	O
of	O
their	O
regular	O
coverage	O
of	O
the	O
home	O
computer	O
industry	O
at	O
that	O
time	O
.	O
</s>
<s>
A	O
number	O
of	O
notable	O
games	O
developers	O
began	O
their	O
careers	O
on	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
,	O
including	O
David	O
Perry	O
of	O
Shiny	O
Entertainment	O
,	O
and	O
Tim	O
and	O
Chris	O
Stamper	O
(	O
founders	O
of	O
Rare	O
,	O
formerly	O
Ultimate	O
Play	O
the	O
Game	O
,	O
maker	O
of	O
many	O
games	O
for	O
Nintendo	O
and	O
Microsoft	O
game	O
consoles	O
)	O
.	O
</s>
<s>
Other	O
prominent	O
games	O
developers	O
include	O
Julian	O
Gollop	O
(	O
Chaos	B-Application
,	O
Rebelstar	B-Application
,	O
X-COM	O
series	O
)	O
,	O
Matthew	O
Smith	O
(	O
Manic	B-Application
Miner	I-Application
,	O
Jet	B-Application
Set	I-Application
Willy	I-Application
)	O
,	O
Jon	O
Ritman	O
(	O
Match	B-Application
Day	I-Application
,	O
Head	B-Application
Over	I-Application
Heels	I-Application
)	O
,	O
Jonathan	O
"	O
Joffa	O
"	O
Smith	O
(	O
Batman	B-Application
:	I-Application
The	I-Application
Caped	I-Application
Crusader	I-Application
,	O
Mikie	B-Application
,	O
Hyper	B-Application
Sports	I-Application
)	O
,	O
The	O
Oliver	O
Twins	O
(	O
the	O
Dizzy	B-Application
series	O
)	O
,	O
Clive	B-Application
Townsend	I-Application
(	O
Saboteur	B-Application
)	O
,	O
Sandy	O
White	O
(	O
Ant	B-Application
Attack	I-Application
;	O
I	O
,	O
of	O
the	O
Mask	O
)	O
,	O
Pete	O
Cooke	O
(	O
Tau	B-Application
Ceti	I-Application
)	O
,	O
Mike	O
Singleton	O
(	O
The	B-Application
Lords	I-Application
of	I-Application
Midnight	I-Application
,	O
War	B-Device
in	I-Device
Middle	I-Device
Earth	I-Device
)	O
,	O
and	O
Alan	O
Cox	O
.	O
</s>
<s>
Although	O
the	O
48K	O
Spectrum	O
's	O
audio	O
hardware	B-Architecture
was	O
not	O
as	O
capable	O
as	O
chips	O
in	O
other	O
popular	O
8-bit	O
home	O
computers	O
of	O
the	O
era	O
,	O
computer	O
musicians	O
David	O
Whittaker	O
and	O
Tim	O
Follin	O
produced	O
notable	O
multi-channel	O
music	O
for	O
it	O
.	O
</s>
<s>
Jeff	O
Minter	O
ported	O
some	O
of	O
his	O
VIC-20	B-Device
games	O
to	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
.	O
</s>
<s>
BYTE	B-Application
in	O
January	O
1983	O
acknowledged	O
the	O
appeal	O
of	O
the	O
Spectrum	O
's	O
low	O
£125	O
price	O
to	O
British	O
consumers	O
and	O
called	O
it	O
a	O
"	O
promising	O
machine	O
"	O
.	O
</s>
<s>
In	O
December	O
2018	O
,	O
one	O
of	O
the	O
alternate	O
endings	O
in	O
Black	O
Mirror	O
:	O
Bandersnatch	O
included	O
the	O
main	O
character	O
playing	O
data	O
tape	O
audio	O
that	O
,	O
when	O
loaded	O
into	O
a	O
ZX	B-Operating_System
Spectrum	I-Operating_System
software	B-Application
emulator	I-Application
,	O
generates	O
a	O
QR	O
code	O
leading	O
to	O
a	O
website	O
with	O
a	O
playable	O
version	O
of	O
the	O
Nohzdyve	O
game	O
featured	O
in	O
the	O
episode	O
.	O
</s>
<s>
Some	O
programmers	O
have	O
continued	O
to	O
code	O
for	O
the	O
platform	O
by	O
using	O
emulators	B-Application
on	O
PCs	O
.	O
</s>
<s>
Since	O
2020	O
,	O
there	O
has	O
been	O
a	O
museum	O
,	O
LOAD	O
ZX	B-Operating_System
Spectrum	I-Operating_System
,	O
dedicated	O
to	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
and	O
other	O
Sinclair	O
products	O
(	O
as	O
well	O
as	O
Timex	O
,	O
Investrónica	O
and	O
many	O
others	O
)	O
,	O
located	O
in	O
Cantanhede	O
,	O
Portugal	O
.	O
</s>
