<s>
The	O
SYM-1	B-Device
is	O
a	O
single	O
board	O
"	O
trainer	O
"	O
computer	O
produced	O
by	O
Synertek	O
Systems	O
in	O
1975	O
.	O
</s>
<s>
Originally	O
called	O
the	O
VIM-1	B-Device
(	O
Versatile	O
Input	O
Monitor	O
)	O
,	O
that	O
name	O
was	O
later	O
changed	O
to	O
SYM-1	B-Device
.	O
</s>
<s>
The	O
SYM-1	B-Device
is	O
a	O
close	O
copy	O
of	O
the	O
popular	O
MOS	B-Architecture
Technology	I-Architecture
KIM-1	B-Device
system	O
,	O
with	O
which	O
it	O
is	O
compatible	O
to	O
a	O
large	O
extent	O
.	O
</s>
<s>
Compared	O
to	O
the	O
KIM-1	B-Device
,	O
enhancements	O
include	O
the	O
ability	O
to	O
run	O
on	O
a	O
single	O
+5	O
volt	O
power	O
supply	O
,	O
an	O
enhanced	O
monitor	O
ROM	B-Device
,	O
three	O
configurable	O
ROM/EPROM	O
sockets	O
,	O
RAM	B-Architecture
expandable	O
on	O
board	O
to	O
,	O
an	O
RS-232	O
serial	O
port	O
,	O
and	O
a	O
"	O
high	O
speed	O
"	O
(	O
,	O
the	O
KIM-1	B-Device
supports	O
about	O
8	O
bytes/second	O
)	O
audio	O
cassette	O
storage	O
interface	O
.	O
</s>
<s>
One	O
capability	O
of	O
the	O
SYM-1	B-Device
is	O
its	O
ability	O
to	O
allow	O
an	O
oscilloscope	O
to	O
be	O
added	O
to	O
provide	O
a	O
32	O
character	O
display	O
under	O
software	O
control	O
.	O
</s>
<s>
As	O
explained	O
in	O
Chapter	O
7	O
of	O
the	O
"	O
SYM	O
Reference	O
Manual	O
"	O
,	O
the	O
vertical	O
input	O
,	O
ground	O
and	O
trigger	O
input	O
of	O
the	O
oscilloscope	O
are	O
to	O
be	O
connected	O
to	O
the	O
"	O
Scope	O
Out	O
"	O
connector	O
AA	O
on	O
the	O
SYM-1	B-Device
board	O
.	O
</s>
<s>
The	O
"	O
Oscilloscope	O
Output	O
Driver	O
Software	O
"	O
code	O
provided	O
in	O
this	O
chapter	O
of	O
the	O
manual	O
is	O
to	O
be	O
entered	O
into	O
the	O
SYM-1	B-Device
'	O
s	O
memory	O
and	O
executed	O
to	O
enable	O
the	O
oscilloscope	O
display	O
.	O
</s>
<s>
Synertek	O
contracted	O
with	O
a	O
company	O
called	O
Eastern	O
House	O
Software	O
to	O
port	O
their	O
Macro	O
Assembler/Editor	O
(	O
MAE	O
)	O
into	O
an	O
ROM	B-Device
.	O
</s>
<s>
MAE	O
was	O
sold	O
in	O
various	O
forms	O
not	O
only	O
for	O
the	O
SYM-1	B-Device
but	O
also	O
for	O
other	O
6502-based	O
computers	O
including	O
Commodore	O
,	O
Atari	O
,	O
KIM	O
,	O
and	O
Apple	O
.	O
</s>
<s>
Other	O
forms	O
of	O
MAE	O
included	O
a	O
cross	B-Language
assembler	I-Language
for	O
6800	O
and	O
8085	O
—	O
and	O
an	O
offering	O
of	O
these	O
cross	B-Language
assemblers	I-Language
was	O
planned	O
for	O
RAE	O
.	O
</s>
<s>
One	O
of	O
the	O
more	O
subtle	O
features	O
of	O
the	O
SYM-1	B-Device
is	O
the	O
use	O
of	O
a	O
look	O
up	O
table	O
in	O
the	O
low	O
memory	O
of	O
the	O
6502	O
.	O
</s>
<s>
This	O
provides	O
a	O
vectoring	O
function	O
in	O
its	O
operating	O
system	O
to	O
redirect	O
subroutine	O
calls	O
to	O
various	O
input	O
and	O
output	O
drivers	O
,	O
including	O
interrupt	B-Application
servicing	I-Application
.	O
</s>
<s>
Users	O
are	O
able	O
to	O
develop	O
their	O
own	O
interface	O
routines	O
,	O
and	O
substitute	O
new	O
vectors	O
for	O
the	O
original	O
vectors	O
in	O
the	O
startup	O
UV-EPROM	O
.	O
</s>
<s>
One	O
of	O
the	O
later	O
home/education	O
computers	O
that	O
uses	O
this	O
concept	O
extensively	O
is	O
the	O
BBC	B-Device
Micro	I-Device
produced	O
by	O
Acorn	O
Computers	O
in	O
the	O
UK	O
.	O
</s>
