Testing all RAM in a Master 128

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0xC0DE
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Testing all RAM in a Master 128

Post by 0xC0DE » Sun Aug 18, 2019 4:28 pm

I've been experiencing some screen glitches (e.g. Bitshifters twisted brain demo) on my Master 128 and was wondering if there's a test program for quickly testing all of my RAM, including shadow and sideways?
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Re: Testing all RAM in a Master 128

Post by VectorEyes » Sun Aug 18, 2019 4:44 pm

Just in Twisted Brain, or elsewhere as well?

There's a known issue in Twisted Brain where it can show some spurious lines in the 'Twister' section. It depends on what screen mode you were in when you booted the demo. It's also known to have problems with some of the more obscure 6845 CRTC chips found in some Master 128s.

So if you're only seeing issues in TB then it could be those issues. Obviously if you're seeing glitches in other products then dodgy hardware seems more likely!

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Re: Testing all RAM in a Master 128

Post by 0xC0DE » Sun Aug 18, 2019 5:10 pm

I noticed the spurious lines while watching twisted brain. Good thing (for me) that it's a known issue. Thanks for clearing that up. It's possibly the only program that produced screen glitches on my Master.

Still out of curiosity, is there such a thing as a test program for all of the RAM in a Master?
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Re: Testing all RAM in a Master 128

Post by kieranhj » Sun Aug 18, 2019 5:13 pm

Can you post a screenshot?

My bad but TB kinda assumes a fresh boot in either MODE 7 or one of the 20K screen modes. Too much testing on an emulator rather than real hw!

If you have the VLSI variant 6845 CRTC chip then it is known not to behave ‘correctly’ compared to the other manufacturers, eg Hitachi.
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Re: Testing all RAM in a Master 128

Post by 0xC0DE » Sun Aug 18, 2019 5:47 pm

Yes I have the vlsi variant of the 6845.will try to make a screenshot.
tb1.JPG
tb2.JPG
tb3.JPG

it glitches in other parts of the demo as wel but this was easily captured.
Last edited by 0xC0DE on Sun Aug 18, 2019 6:20 pm, edited 1 time in total.
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