A1200 rev 1D.1 issue

patrik · 06 June 2007, 19:33

Got an A1200 here with a rev 1D.1 motherboard which has a weird issue I was wondering if anyone has experienced or heard of:

If I add a Microbotix MBX1200z ram expansion card it will become very unstable when doing certain things. It can just idle along infinitely, but a good way to crash it is to simply grab an icon and drag it around. This happens even when booting from a unmodified workbench disk without a harddrive attached or anything.

- The 1200z card works fine in my other A1200 with a rev 2B motherboard.
- I have tried running the 1200z card without the fpu and different simm-memories, but it makes no difference.
- The rev 1D.1 A1200 works fine with a Blizzard1230-IV or a Blizzard1260.

patrik · 06 June 2007, 20:21

I have to answer to this myself as a friend suggested a solution which solved the problem - apply the timing fix which consists in removing the two capacitors E123C and E125C.

Was a bit reluctant as the only info I could find regarding applying this fix to a rev 1D.1 motherboard was a vague comment in the list of A1200 motherboard revision changes (at big book of amiga amiga hardware) that the difference between 1D.1 and 1D.3 was merely the removal of these two capacitors.

fc.studio · 06 June 2007, 23:36

I experienced for about two years a Microbotics MBX1200z 8MB ram and 68882/28Mhz FPU expansion card with my A1200 rev 1D.1 and I can tell you that this was very stable. Sometimes it lost date/time after guru for running old badly written programs. This doesn't happen with my current Blizzard 1230-IV.

In my opinion it is a good ram-card.

I gave it to a friend having Escom A1200 and, for what I know, he did not have any problems. However he uses Amiga just for games and doesn't use much WorkBench.

P.S.:
Just got my 2nd A1200 and it is a rev 2B. For pure coincidence we have two A1200 with the same rev.

06 June 2007, 19:33	#1
patrik Registered User Join Date: Jan 2005 Location: Umeå Age: 43 Posts: 922	A1200 rev 1D.1 issue Got an A1200 here with a rev 1D.1 motherboard which has a weird issue I was wondering if anyone has experienced or heard of: If I add a Microbotix MBX1200z ram expansion card it will become very unstable when doing certain things. It can just idle along infinitely, but a good way to crash it is to simply grab an icon and drag it around. This happens even when booting from a unmodified workbench disk without a harddrive attached or anything. - The 1200z card works fine in my other A1200 with a rev 2B motherboard. - I have tried running the 1200z card without the fpu and different simm-memories, but it makes no difference. - The rev 1D.1 A1200 works fine with a Blizzard1230-IV or a Blizzard1260.

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06 June 2007, 20:21	#2
patrik Registered User Join Date: Jan 2005 Location: Umeå Age: 43 Posts: 922	I have to answer to this myself as a friend suggested a solution which solved the problem - apply the timing fix which consists in removing the two capacitors E123C and E125C. Was a bit reluctant as the only info I could find regarding applying this fix to a rev 1D.1 motherboard was a vague comment in the list of A1200 motherboard revision changes (at big book of amiga amiga hardware) that the difference between 1D.1 and 1D.3 was merely the removal of these two capacitors.

06 June 2007, 23:36	#3
fc.studio Cat lover Join Date: May 2004 Location: Italy Age: 54 Posts: 804	I experienced for about two years a Microbotics MBX1200z 8MB ram and 68882/28Mhz FPU expansion card with my A1200 rev 1D.1 and I can tell you that this was very stable. Sometimes it lost date/time after guru for running old badly written programs. This doesn't happen with my current Blizzard 1230-IV. In my opinion it is a good ram-card. I gave it to a friend having Escom A1200 and, for what I know, he did not have any problems. However he uses Amiga just for games and doesn't use much WorkBench. P.S.: Just got my 2nd A1200 and it is a rev 2B. For pure coincidence we have two A1200 with the same rev.

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