800XL, 130XE as a Ram Chip Tester

[KLund1]

I am having a hard time with ram chips in many different vintage systems. 

I was looking for a dram tester for 4116, 4164, 41256, and others. 

The ones I found are like $1,000! 

I found topics to build arduino testers, but that is still above my ability to build.

I thought maybe I could use a working 800XL board as a 4164 tester. Solder in a ziff socket in the correct part of the board, and if it boots it should be good. Then use the built-in self test to stress it a bit further

DO the same for 256 chips in a 103XE. What machine could I use for 4116? 600XL?

Thoughts, ideas, suggestions?

 

[Ute]

I suppose you could just use SYS-Check V2.2 in your 800XL and 130XE.

 

Edit: Might get tedious swapping the chips in and out.

Edited February 7, 2020 by Ute
Additional thought

[Rybags]

A 16 chip 130XE would be better - a single bad chip could be sufficient to not allow an 800XL to function.  You need good z-page RAM for use as workspace and pointers for testing the remainder (OK, you could in theory do a ROM based test that didn't rely on any working RAM but it'd be a tedious thing to create)

 

Using the extended banks you should have main memory entirely functional though don't some Ram faults cause the chips to maintain a constant signal on their data line one way or the other that could screw everything up?

 

In the modern day though I do think something like a kit based affair would be a better option.

[Geister]

I don't think a 130XE could help you test 256K rams unless you already have a 320 upgrade installed.  Most 130 XE have 2 banks of 4164 chips installed.  

A 600XL won't be much help testing 4116's as they contain 2 4416 chips, not 8 4116's.  4416'S are 16kX4 bits while 4116's are 16KX1 bit.

Maybe an original 400 or 800 memory board would have socketed 4116 chips.

[KLund1]

No, I'm sorry. I think we may have missed my bit crazy idea. I do not want to get an Atari working. I have many that do. I need a way cheaply test ram chips. I know Atari's best, so I thought I'd start there. I would be using bare boards, no case or RF shield.

If the 800XL dose not boot, I have a bad chip and in the trash it goes, next chip. If it dose boot, use the self-test to test it further. Use a ziff socket to easily add/remove chips?

4164 = 800XL (best socket number to use for this)

4116 = ?? 600XL ??

41256 = ?? probably need a highly modified Atari.  Not something I would use for just testing. what other cheap machine/motherboard might I use here?

(SYS-Check V2.2 would be good to have for helping with my other atari issues that come up.  Is it still available?)

 

[Rybags]

Note that you'll probably not get ICs with higher pin count to go into ZIF sockets.

 

What might be a better idea is to design a PBI/ECI board that you can populate with specific chip types.  Then may as well make it dual function, testing as well as Ram upgrade.

[xrbrevin]

see here:

https://atariage.com/forums/topic/289391-dramarduino-dram-tester-with-arduino/?tab=comments#comment-4242062

[+bob1200xl]

Why not just use the native m/b for a particular type? i.e. 4164s in a 1200XL or 800XL, 4116s in a 400/800. The 41256s can be run in a 1200XL or 800XL with a minor circuit change.

 

Unless you have hundreds of chips to test, (in which case, the PBI thing sounds most feasible) just use the sockets that come with the machine - test 8 chips of a type at once.

 

There is an Atari diagnostic cartridge out there that seems to work pretty well for testing RAM, and other stuff, for that matter.

 

Bob

[KLund1]

24 minutes ago, xrbrevin said:

see here:

https://atariage.com/forums/topic/289391-dramarduino-dram-tester-with-arduino/?tab=comments#comment-4242062

I saw that link. Thanks. Much beyond my abilities. Same with designing a PCB.

I need a almost plug and play solution.

I'd get a ziff 16-pin socket, or clip legs of the next size up, and put that into 2 sockets stacked on the atari for clearance.

I think 1 600XL will then work for 4116's. Plug one in, if it boot good, if not in the trash..
What might work for 41256's? I could use a PX/XT clone board, but that is a lot to setup, board, video card, crt, keyboard,PSU. Plus finding a board that show the ram error location on screen during post. Then deciphering the code. Anything simpler to use?

[Geister]

Nope, still no 4116's in the 600XL.  They had 4416's.  Different ram, different pin-out.

[Rybags]

In theory you should be able to test 4116s in an 800XL though you'd probably get 4 mirrored images which would prevent normal OS startup, though a diag mode cartridge would still start.

But every chance it'd crash if it didn't specifically test for such a condition and take action to avoid inadvertant memory overwriting.

[KLund1]

Oh, need to stop being dyslexic, 4416, 4116, sorry.

So what would work for 4116's? 

 

 

[Rybags]

I'm not sure anything used those, possibly some later memory expansion boards for the 800?