exxos's Atari, Amiga & retro forum

A very initial version of DiagROM for the ST is available here.

https://github.com/terriblefire/diagromst

Basically do not expect anything. It boots on my ST and I see the output on the serial port.

Have fun and please submit fixes.

Awesome. Will try that out asap!

For those who don't know about this software.. First example is you can find faulty ram bits when the machine doesn't even boot up.

exxos wrote: ↑Sun Sep 16, 2018 9:42 am For those who don't know about this software.. First example is you can find faulty ram bits when the machine doesn't even boot up.

In which regard is it preferable to the official Atari diagnostic ROM cartridge?

The most evident, you don’t have to open the Atari to use
the diagnostic cartridge.

czietz wrote: ↑Sun Sep 16, 2018 11:00 am In which regard is it preferable to the official Atari diagnostic ROM cartridge?

It depends what you want to do, DiagROM is more "low level" diagnostics, so you can boot these ROM's even on a machine which doesn't boot TOS or the Atari diagnostic rom.

Its ported from the Amiga by Terriblefire, so its much WIP here. But I have seen it in use and I think it will be a valuable tool for those who have machines with bad-ram installs and the machine doesn't boot up. DiagROM will let you debug low level stuff like RAM faults. AFAIK, no other software has ever been created to do that.

crashman wrote: ↑Sun Sep 16, 2018 11:04 am The most evident, you don’t have to open the Atari to use
the diagnostic cartridge.

The point is, the diagnostic cartridge will NOT boot if the machine has bad ram or TOS isn't running.. so its basically useless. Diagrom will however boot on such machines.

Atari diagnostic ROMs will also detect severe RAM faults that prevent TOS from booting. It will exactly show you which address or data line is stuck, for example. In fact, the Atari diagnostic will even start on a machine with zero RAM installed. (Of course, no video output there, just serial.)

Of course you're right that the first few bytes of the TOS ROMs need to be readable for the machine to jump into the diagnostic cartridge ROM. However, if you have to change ROMs anyway (like you would have to with this DiagROM), you could always insert a known working set of TOS ROMs and then boot into the Atari diagnostic cartridge.

It's sure nice that terriblefire ported this and released it as open-source, but right now I don't understand the use case for it.

If you dont want to use it then don't. I dont care. It works perfectly for my needs and I decided to share. The Diagnosis cart doesnt. It stops too quickly and is not interactive.

I use this ROM to bring up new 68000 machines and to figure out why my accelerators dont work. It detects things like broken UDS/LDS lines. Soak tests ram, and has an interactive editor for visually seeing what is going on.

It also does everything over serial port and video. So its perfect for a zero hardware working diagnosis.

crashman wrote: ↑Sun Sep 16, 2018 11:04 am The most evident, you don’t have to open the Atari to use
the diagnostic cartridge.

There is absolutely nothing stopping someone from compiling this to a cart. Its open source.