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Philsan

130XE 576K upgrade by Scott Peterson

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I friend of mine has some problems with his 130XE 576K Scott Peterson's RAM upgrade (https://www.atariarchives.org/cfn/12/02/0081.php)

 

He gets different results with known memory test programs therefore he made his own program:

memorytester-xe.atr

 

Can somebody with that memory expansion check if this program is OK?

 

Thanks!

 

 

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The upgrade you linked uses PIA bits 1,2,3,5,6 (Bit 1/BASIC software control is lost)

 

I think most popular 576K upgrades nowadays use PIA bits 2,3,5,6,7. 1MB is most commonly achieved by adding bit 1.

 

It's most likely the RAM tester is not designed to check bit 1. Maybe a tool capable of testing 1MB would pick up on it.

 

Have you tested with Satantronic XRAM? http://atari.sk/extended-ram-test-0-22-0-xram0220-xex/

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Hello guys

 

A memory tester shouldn't exclude any of the bits in $D301.  It should be able to find out for itself which bits are used.

 

Sincerely

 

Mathy

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Oddly enough, during my epic cleanup of old stuff last week, I came across a printout of this upgrade!  Also the 1 meg upgrade.  Strangely enough, I did not find the printout of the 320K upgrade, which is the one that I did BitD.  These would have been printed out in the 80s.  Yes, you can expect to see me on an upcoming episode of "Hoarders".

 

 

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I posted the 320K Peterson with ANTIC following mod here on AA more than once, have fun doing the search though.. I hope it's the one with the resistor added for the ram as well...

Edited by _The Doctor__

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Philsan,

Have your friend give these memory testers a try, especially EXTEST.COM inside MEMRAMCHECKTEST.ATR.

https://atariage.com/forums/topic/189604-small-thing-memtest-10-1996-jaku-b/?do=findComment&comment=3815398

 

 

I was thinking the Peterson was a Rambo knockoff, am I wrong? Again?

 

At any rate EXTEST.COM should exclude the rambo system banks from the list of usable banks and thus be 4 less banks than most other testers, IF that Peterson is a rambo type memory expansion.

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I am that guy! ;-)

 

The biggest issue at the moment I have a NON WORKING keyboard (mylar and PCB connector are broken or loosy) so I can not start any software by typing its name on the keyboard. At the moment I can use SIO2USB with a MyPicoDos autorun code to run all software I need to check these ramchips, but a lot of program I tried gave me wrong results.

 

Please have a look at the code I wrote in my github repo: https://github.com/gianlucarenzi/AT2019

 

and look for the ATARI-Driver folder. There is a megaram.c code. I tried both formats (130XE 192K mode and 576K mode) but they works in the emulator atari800. Tonite I will try them in my real hardware so I can see if they work or not.

Please feel free to give me suggestions or hints to write this kinda memory tester for Scott Peterson 576K upgrade I did in 1988. I have all printed instructions... ;-)

 

Regards,

 

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I feel your pain with real hardware struggles, gianlucarenzi. Best of luck with that issue.

 

I've been to your github posts, but I don't understand C and do my code writing in assembler. BUT I did find out that emulators don't work like they often say they do when counting on the various expanded memory choices we have there. And I haven't tried all emulators either, just Atari800win.

 

Starting at this thread:

 

In the beginning there in that thread, I wasn't aware of the issues of Rambo type extended memory upgrades. First thing I learned is that my emulator was lying to me and I had to "pretend" the code I was writing did what I wanted it too. It often didn't which is why I call for so many screenshots running on real hardware. All I had to work with WAS an emulator, but eventually the code was approved by those running real Rambo upgrades.

 

I have issues with using this upgrade on a 130XE as it has bit 5 use firmly reserved for ANTIC access modes and I have zero confidence one can take an upgrade for a XL and slap it into a XE without issues. I'm thinking there are issues and I have NOT approved the peterson for XE use, even though I've seen some 320K versions that also had the same issues. None of those issues have been cleared up for me, so I fear I'm not going to be able to work up a fix in any case. Much less guide you with pointers in a language I don't understand (C).

 

I don't see how one can use bit5 as a banking byte and have it count as "one more valid" bank, it should be discounted as it's an ANTIC access bank. Yet it's still used for "one more valid bank" counts. I don't understand using both systems and still have both systems work at all. I have no code written to test for these anomalies either. On the XL we don't have ANTIC access MMU (U34), it would seem best to limit the work to that platform. But only sometimes does this seem to be clear path to me. Simply put, I have not resolved my issues in order to voice a clear opinion on the matter.  I clearly don't know what to think about it. I'm doing good to detect a genuine Rambo with my code.

 

So such as it is, welcome gianlucarenzi to all you can feast on, glad to have you on board too.

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What exactly do you feel won't work with a 192/320 Peterson with ANTIC following?

This is an upgrade in use forever, and has next to no complaints. Cheap and easy at the time.

It is better to used latched or multiplexed memory upgrades of course.

Why no just go with compyshop upgrade if worries persist?

or possibly Mathy's?

http://www.mathyvannisselroy.nl/memory_expansion/The slightly different memory.htm

or U1M

or even this

https://www.horus.com/~hias/atari/#sram512k

Edited by _The Doctor__
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some further 130XE 192XE 320XE memory upgrade info

https://atariage.com/forums/topic/281132-atari-130xe-4164-best-replacement-or-upgrade-ram-chips/?do=findComment&comment=4079782

mathy saved some discussions on all the memory upgrades that led to his...

http://www.mathyvannisselroy.nl/memup.txt

 

Edited by _The Doctor__
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