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Test Memory Extensions Utilizing SDX 4.47

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During the last Winter I experienced some aging problems with XL machines that had been upgraded with different memory extensions in the 1980s. Some were no longer working in reliable manor. Starting the usual procedures to identify the possible reasons didn't work out well in a timely frame. Changing DRAMs and re-wiring sometimes seemed to solve the issues. But there was no reliable test routine serving my needs. So I dug up my tool box and found an old program written by TKS. It helped a lot and I could solve all hardware issues with those old memory extensions efficiently.


Nevertheless, as the program by TKS was written for a different purpose, it was not that convenient in usage when testing memory extensions. The core routine in machine language serves all needs, is fast and probably cannot be done better. But the BASIC program around it in my view needed to be arranged differently to serve the test purpose. So I changed it to my needs, adapted it to SDX 4.47 and made a small SDX boot disk for my needs. I cannot tell if it can test every memory extension but at least it should be able to test all memory extensions controlled by PIA port B. May be it is of some use, so find it attached.


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Thanks also for sharing the program. It seems to be a PAL driven code because the upper portion on GR. 8 screen is out of sight on NTSC..


Cannot confirm this for real hardware as I do no longer have any NTSC A8. In Altirra it works fine with all versions of extended memory in NTSC mode. As explained in the text file on the image the screen output differs depending on the hardware of the RAM extension. As long as the reported data match the hardware of the tested memory extension and no failure comes up everything is fine.


I was told it even works proper when testing the rapidus.

Edited by GoodByteXL
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