English Amiga Board - View Single Post - Blizzard 1230-IV 128mb instability

pipper · 28 August 2017, 19:22

Hi,

I just recently got back to my A1200 (200w AT PSU)after a long period of absence. I wanted to update the memory to 128mb (why not...) but I'm facing lots of instability.
It looks like a piece on the Blizzard is causing trouble when the card gets warm. The instabilities are severe, causing crashes all over the place...

I tried several modules:
16mb 60ns (doublesided): fully stable in 70ns setting. In 60ns gets unstable after a while when the CPU reaches around 50c. Memory testing programs don't show a problem, even in warmed up state.

128mb 60ns (doubesided): gets unstable after warmup. Memory tests do not reveal a problem, though.

128mb 50ns (doublesided): gets unstable after warmup. After warmup, memory tests show a few addresses (they are pretty consistent) that have values which differ in bit 3. These failures are revealed by 'MemCheck' ADR test where the test writes the memory address as value.
So for instance, address 0x7c0c9108 would get the value '0x7c0c9108' assigned, but when reading it back, the value '0x7c0c910c' is returned. A few memory addresses might exhibit such behavior, 0x7c0c9108 being the one that shows up consistently .

64mb 60ns (singlesided): fully stable under all conditions.

So, it looks like something on the accelerator board is causing these issues - and I'm not convinced its the memory modules that are at fault... particularly as the the problems arise only after warmup and not immediately after startup.

Does anyone have an insight on what to lookout for on the board? There are no bad solder joints that can be seen by the naked eye. Is there anything different in the addressing hardware between the single sided and double sided modules?
Schematics would help tremendously :-)

thanks!

28 August 2017, 19:22	#1
pipper Registered User Join Date: Jul 2017 Location: San Jose Posts: 652	Blizzard 1230-IV 128mb instability Hi, I just recently got back to my A1200 (200w AT PSU)after a long period of absence. I wanted to update the memory to 128mb (why not...) but I'm facing lots of instability. It looks like a piece on the Blizzard is causing trouble when the card gets warm. The instabilities are severe, causing crashes all over the place... I tried several modules: 16mb 60ns (doublesided): fully stable in 70ns setting. In 60ns gets unstable after a while when the CPU reaches around 50c. Memory testing programs don't show a problem, even in warmed up state. 128mb 60ns (doubesided): gets unstable after warmup. Memory tests do not reveal a problem, though. 128mb 50ns (doublesided): gets unstable after warmup. After warmup, memory tests show a few addresses (they are pretty consistent) that have values which differ in bit 3. These failures are revealed by 'MemCheck' ADR test where the test writes the memory address as value. So for instance, address 0x7c0c9108 would get the value '0x7c0c9108' assigned, but when reading it back, the value '0x7c0c910c' is returned. A few memory addresses might exhibit such behavior, 0x7c0c9108 being the one that shows up consistently . 64mb 60ns (singlesided): fully stable under all conditions. So, it looks like something on the accelerator board is causing these issues - and I'm not convinced its the memory modules that are at fault... particularly as the the problems arise only after warmup and not immediately after startup. Does anyone have an insight on what to lookout for on the board? There are no bad solder joints that can be seen by the naked eye. Is there anything different in the addressing hardware between the single sided and double sided modules? Schematics would help tremendously :-) thanks!