Thanks for sorting that out. I don't know how the memory layout works exactly but could it still be only one chip if you take the fact into account the the same problems appeared when disabling the second half of RAM (bank 1)? The speckles appear at the end of the RAM, where video memory is located so that would sound like the second bank to me. The ST has these SMT rams, they look really hard to replace. And are they even sold a piece these days?czietz wrote: ↑Tue Oct 02, 2018 7:19 pm The error shown is in bit 13:
0xFFDF = 1111111111011111 was read, but...
0xDFDF = 1101111111011111 was expected.
If the error always is in bit 13 (the errors you previously posted were and also the speckle pattern looks reasonably repetitive to me), then you know which RAM chip to change.
PS: Even though I gave it some thought, I'm still puzzled by which effect the RAM access speed could be halved.
1040 STF showing occasional rogue pixels
Re: 1040 STF showing occasional rogue pixels
Re: 1040 STF showing occasional rogue pixels
Sorry, I had missed that it also happened when the upper bank was disabled. It's indeed unlikely that two RAM chips (for lower and upper bank) are bad. It then points more into the direction of the buffers (74xx373, 74xx244), but on the other hand defective buffers cannot explain why the errors primarily happen in the last kilobytes of RAM.
Re: 1040 STF showing occasional rogue pixels
Did you try the freezer spray ?
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
Re: 1040 STF showing occasional rogue pixels
Yeah, I hit all of the ram and the CPU, MMU, GLUE, buffers, shifter. It didn't seem to make any difference. Honestly, I didn't want to deplete the complete can, since it's quite expensive. So I sprayed the said components for only a second or two each (I did give the RAM section about 5 sprays I think).
Re: 1040 STF showing occasional rogue pixels
What speed are the DRAMs ?sandord wrote: ↑Wed Oct 03, 2018 10:17 am Yeah, I hit all of the ram and the CPU, MMU, GLUE, buffers, shifter. It didn't seem to make any difference. Honestly, I didn't want to deplete the complete can, since it's quite expensive. So I sprayed the said components for only a second or two each (I did give the RAM section about 5 sprays I think).
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
Re: 1040 STF showing occasional rogue pixels
150ns likely. I would solder a wire over L51 (next to PSU connector) and see if that does anything. Next change the 33R resistors with 68R and see if that does anything..
Very odd issues indeed...
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
Re: 1040 STF showing occasional rogue pixels
Running YAART with a wire over L51 for over 3.5 hours now. No bad pixels or memory test errors at all. Promising, but I'll leave it running for a few more hours.
Re: 1040 STF showing occasional rogue pixels
Fingers crossed!
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
Re: 1040 STF showing occasional rogue pixels
7 hours, 122 passes, 0 errors and no bad pixels! This is looking gooood!
If only we didn't have the 50% RAM speed problem