Vector Graphic ROM Monitor

Announcements about the Altair 8800 Clone including software and hardware updates.

Vector Graphic ROM Monitor

Postby AltairClone » October 4th, 2015, 9:48 pm

The ROM monitor 2.0c for the early Vector Graphic computers was a 1K monitor written for the 8080 (later versions were Z80 specific). This monitor is much more useful than the Altair Turnkey monitor and I have ported it to work on the Altair computer. The code is now available in the ROMs directory on the support page.

The command prompt is an asterisk. Command entry takes a bit of getting used to. There is no backspace or delete. If you make a mistake, type ctrl-c to get back to the prompt and re-enter the command. Most executing commands can be aborted by ctrl-c.

All commands are a single letter, all addresses are four hex digits, data bytes and I/O port numbers are two digits. The 2SIO port selection (0 or 1) for the "H" (load hex file) command is a single digit.

The spaces you see between the parameters are typed by the monitor - you don't type them. The command executes as soon as the last required byte is typed - CR does not need to be typed.

Here is a list of monitor commands:

A SSSS FFFF ascii dump
B jump to disk boot loader
C SSSS FFFF CCCC compare blocks
D SSSS FFFF dump in hex
F SSSS FFFF DD DD two byte search
G SSSS go to and execute
H P load intel hex file from 2SIO port 0 or 1
I PP input from I/O port
J SSSS jump to and execute (same as G)
K jump to zero
L SSSS FFFF load and go
M SSSS FFFF DDDD move block
N non destructive memory test
O PP DD output to port
P LLLL program memory
Q SSSS FFFF compute checksum
R SSSS FFFF read cassette
S SSSS FFFF DD search for single byte
T SSSS FFFF test memory
V SSSS FFFF verify tape
W SSSS FFFF write tape
X SSSS FFFF DDDD exchange block
Z SSSS FFFF DD zero or fill memory
AltairClone
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Re: Vector Graphic ROM Monitor

Postby AltairClone » January 14th, 2016, 3:29 pm

I've done further updates to this monitor to make it a better fit and more useful on an Altair computer. I call the updated version "ALTMON" and have created a new directory for it called "Altair Monitor" in the ROMs folder on the support page.

While a monitor like this may not be that useful for the Altair Clone (the computer is too reliable!), it is a very useful monitor when restoring/repairing a real Altair 8800.

Mike
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Re: Vector Graphic ROM Monitor

Postby toml_12953 » August 16th, 2016, 8:46 am

AltairClone wrote:I've done further updates to this monitor to make it a better fit and more useful on an Altair computer. I call the updated version "ALTMON" and have created a new directory for it called "Altair Monitor" in the ROMs folder on the support page.

While a monitor like this may not be that useful for the Altair Clone (the computer is too reliable!), it is a very useful monitor when restoring/repairing a real Altair 8800.

Mike


Why were the cassette commands removed? I'd think they'd be very handy, especially when working on a real 8800. Was the format or encoding too different?

Tom L
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Re: Vector Graphic ROM Monitor

Postby AltairClone » August 16th, 2016, 6:19 pm

Orignally, I modified the cassette routines to work with the Altair 88-ACR board. However, with very little room in the 1K PROM, I removed the cassette functions to make room for other features I felt more useful to today's vintage computing hobbyist.
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