Possible to simulate bad RAM?

[Frankie]

This is an unusual request, but is it possible to simulate bad RAM in WinUAE?

I'm looking at a few memory testers on Aminet but there's no way of knowing which is best because WinUAE's RAM is obviously fine.

So is this possible?

[Toni Wilen]

It is not supported and it wouldn't really help because there can be countless ways RAM chip can get damaged. (single bit, short between address or data lines, whole row or column returns same data, partially damaged something causing random behavior, some combination of above and so on..)

[BastyCDGS]

Just wait if your underlying system RAM becomes problematic.

With some luck, your memory detection program on Amiga will respond before your host operating system freezes.

Serious answer:
Your question is pointless from the very beginning. Use host features to detect memory errors. memtest86, etc.

Even if Toni would implement it, it would not show real best tool, but only the one which is best at Toni's implementation. It doesn't mean real hardware RAM errors yield the same result.

[Frankie]

Originally Posted by Toni Wilen

It is not supported and it wouldn't really help because there can be countless ways RAM chip can get damaged. (single bit, short between address or data lines, whole row or column returns same data, partially damaged something causing random behavior, some combination of above and so on..)

Understood. Thanks for the response, Toni.

Originally Posted by BastyCDGS

Even if Toni would implement it, it would not show real best tool, but only the one which is best at Toni's implementation.

True, but seeing even one of those programs correctly determine that the RAM is corrupt under emulation would lead me to believe that it's probably worth using on a real Amiga. All I'm trying to do is determine which of the myriad of memory testers on Aminet (probably) work and are worth keeping.

[dalek]

For day to day use I use Keir's AmigaTestKit checker. The best (most comprehensive) to me seems to be the MBRTest-2 that's on the Microbotics disk - which you can get here: http://amiga.resource.cx/exp/mbx1230

[Tomislav]

There is DiagROM from Chucky if you can write EPROMs. This is still in development.

http://www.diagrom.com/

[Foebane]

Originally Posted by Frankie

All I'm trying to do is determine which of the myriad of memory testers on Aminet (probably) work and are worth keeping.

If all of these memory testers POKE memory in specified locations and then PEEK those specified locations to see if they're the same, then I'd say they all work fine. It can't be that difficult to program them, after all.

[Frankie]

@dalek: Thanks for the suggestions. I'll look into them soon

@Tomislav: Unfortunately I can't write EPROMS, but I've noted it for future.

@Foebane: That's the theory, but a couple of those that I tried on Aminet crashed almost immediately. Definitely not a good sign.

[r.cade]

I always did a silly low-tech RAM check. Drag/drop folders/disk to RAM. If it fills up and runs out of RAM before locking up or crashing, RAM is probably good.

But this doesn't really help tell you "what" RAM is bad unless you disable some of it with switches until the crashes stop. Many RAM cards had specific tests you could run that may be able to tell you what chip is bad.

[Frankie]

Originally Posted by r.cade

I always did a silly low-tech RAM check. Drag/drop folders/disk to RAM. If it fills up and runs out of RAM before locking up or crashing, RAM is probably good.

I used to do that back in the day