At 10:25 AM 3/14/97 -0600, you wrote:
>If anyone knows or has an eprom burner or information about burning
>cartridges on the atari, I would appreciate hearing from them. My dad has a
>RomMax 4G Universal Eprom Programmer at work, and we cant seem to read the
>eproms from any cartridge. I would like to figure this out, maybe there is
>a proprietary scheme, but we can't seem to figure it out.
Hmmm... have not looked at Atari ROMs since the days when I used to service
them, but they might have used a trick I first noticed on the Apple // ROMs.
One of the chip select lines is inverted from the norm, so if you put it in
a standard programmer it would always appear blank. As our programmers at
the time were not real bright, I built a test socket that we plugged into
the programmer and then plugged the ROM into the test socket.
The test socket had a 7406 ('04?, it's late) hex inverter and a set of
jumpers on it that allowed us to selectively invert any/all of the chip
select lines. Problem solved! And curiously enough, the inverted line
tended to be the program voltage line on the matching EPROM so if we needed
to install one in an Apple // as a replacement we just needed to remember
to fold that pin under.
Might be worth a look.
-jim
---
jimw_at_agora.rdrop.com
The Computer Garage - http://www.rdrop.com/~jimw
Computer Garage Fax - (503) 646-0174
Received on Sat Mar 15 1997 - 00:54:53 GMT