Apple //c high memory app crashes?

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Apple //c high memory app crashes?

I recently just got my very first Apple II, a //c ROM version 255 hooked up to a floppy emu. The computer turns on, seems to boot fine, AppleSoft works etc. I can run some programs fine like Oregon Trail but others either crash straight away like every version of Merlin, crash a bit later like Apple II desktop or a2osX or have strange symptoms. Sometimes it's just one or two characters being replaced by the delete character other times it's weird issues like all visible text in AppleWorks just vanishing.

 

I'm thinking since some programs work, particularly older ones like Big Mac there might be an issue with extra 64K RAM or the 80 column firmware but I'm not sure and I'm a pretty big 8 bit noob outside of what I've seen in YouTube videos.

 

How might I best go about testing what might have failed? Since it's ROM version 255 I don't have the self test built in and trying to boot the Apple //c dealer diagnostics disk I found on the web just resulted in grey squares.

 

Anybody have a idea what might be the cause of this? Thanks.

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The Apple Service Dealers

The Apple Service Dealers Diagnostic Disk //c is what you will likely want to try using. 

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Is that the same as the

Is that the same as the "Apple IIc - Diagnostic diskette program" floating around the web? I've tried it a few times and downloaded it from a couple places and all I get is pattern of grey rectangles which shift for a bit and then freezes on one pattern. Is there some other trick I don't know to get it working? Or is my problem just messing up what I need to see what the problem is?

 

I did try MECC computer inspector which sometimes finds a memory error in the AUX memory, but I still don't know what chip would need replacing. I also tried another modern RAM test program that finds no problems although it's not designed to run on the //c.

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What RAM card (exact model,

I use my original Apple //e and //c  Dealer Diagnostics disk. I am unsure if the one in the archives is identical, but I have also made a version that circumvents boot sector protection using ProDOS 2.4.2 The version of my diagnostics disk is v.4.0. If you provide a photo of its menus I might be able to visually compare it to what I use. It also helps to have the Dealer Diagnostics literature. Let me know if you need that. 

 

I plan to upload that image to Asimov when I have a chance to convert it to a disk image. I also have a personal version of A2D, and ProDOS master disk, in 800K format, with the diagnostics tools and other useful utilities, and I eventually plan to upload these, as well; but they require an 800K 3.5 drive. 

 

Do you have an EXP card in the //c, or is it the stock 128K system?

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It is a stock system.

It is a stock system. Original revision so there's no slot for a memory upgrade either.

 There is no menu when I try to boot the diagnostics disk I grabbed off the net. All I get is the grey rectangles like the image below. Could it be the boot sector protection? I don't have the Dealer Diagnostics literature either. So that would probably help.

 

Otherwise I'm thinking a ROM update to 4X might be only other option to figure out what the problem might be, which might be worthwhile for the other benefits it'd bring although I need to get a few things to make that work.

 

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SyphonMonkey wrote:It is a
SyphonMonkey wrote:

It is a stock system. Original revision so there's no slot for a memory upgrade either.

 There is no menu when I try to boot the diagnostics disk I grabbed off the net. All I get is the grey rectangles like the image below. Could it be the boot sector protection? I don't have the Dealer Diagnostics literature either. So that would probably help.

 

Otherwise

 

I installed the experemental ROM 4X in my //c, and it's absolutely worth it. Unlike the later Apple ROMs, you can boot from an external drive with it.

 

Here is the literature that covers the Dealer Diagnostics:

https://archive.org/details/Apple_Service_Technical_Procedures_Apple_II_Family_Volume_One_1992-03_Apple_PN_072-0229 

 

 

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Thanks! I did manage to find

Thanks! I did manage to find version 4.1 of the service diagnostics disk and get it bootable (it's an 800K image so I had to drag the relevant sections into a smaller 140K image using Ciderpress). Unfortunately it doesn't tell you what RAM chip is bad, just that the RAM is indeed bad. Oh well, good to know.

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