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Author Topic: A2000 Rev.6 Only 512kb showing up  (Read 2613 times)

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Offline TatsuTopic starter

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A2000 Rev.6 Only 512kb showing up
« on: November 21, 2010, 05:33:40 PM »
I should have 1MB in total and i want all to be chip offcorse. I tried diffrent jumper settings and swithed some chips with an old A500 to no vail.
But when I set J101 and J500 to have 1MB, the computer does not boot. With kick 2.04 the screen flashes with some lines with different colours. With kick 1.3 the screen stays gray but the power lamp flashes continuosly. Reseting does nothing.
Gary is 8372A and i have tried a newer revision also, no change.
But the other 512kb that should show up as "other" or "fast" mem is not showing up at all either. Could some memory chips be broken? I have 8 pieces of MB81C4256-10p I am not sure they add up to 1MB but they should when I have Rev6 I believe.
A1200T PPC/060 Voodoo5 SD/FF
A2000 Blizzard 060 CV/3D
 

Offline TatsuTopic starter

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Re: A2000 Rev.6 Only 512kb showing up
« Reply #1 on: November 21, 2010, 07:26:13 PM »
Thanks for replying. I meant offcourse agnus, not gary. I will hunt for theese pads then.
I see no other memory then 512kb chip, if i have not made myself clear on that subject. I have a strange 1MB commodore card wich fit in the cpu/mmu-slot it shows as 512kb fast. But i cant seem to make that either to be chip mem, but that could very likely be impossible also.
A1200T PPC/060 Voodoo5 SD/FF
A2000 Blizzard 060 CV/3D
 

Offline TatsuTopic starter

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Re: A2000 Rev.6 Only 512kb showing up
« Reply #2 on: November 21, 2010, 08:25:59 PM »
No, i am not using the ram-card normally, just tested it in a vague hope it really could be used as chip ram. Normally i have 8mb fast mem on my trump card anyway so i really have not noticed i was lacking half the memory of the mobo. I just now decided I wanted the other half MB to be chip mem. But it is nowhere to be found.
I found a open jumper J102 near agnus. But it probably just sets it for ntsc, and it has only 2 pads anyway. I will search some more.
A1200T PPC/060 Voodoo5 SD/FF
A2000 Blizzard 060 CV/3D
 

Offline TatsuTopic starter

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Re: A2000 Rev.6 Only 512kb showing up
« Reply #3 on: November 21, 2010, 10:17:57 PM »
I closed J102 but it did no difference at all. I am starting to think something is broken on the motherboard.
J101 can be in any position when J500 is open. But when J500 is closed only one position is possible on J101, the other shows the symptoms i allready told. I have switched Gary, Agnus and denise with an A500 but nothing helps. Its strange there is no problem when the extra 512kb is set for fastmem, other than that it doesnt show up. The computer is rock stable in that configuration.
A1200T PPC/060 Voodoo5 SD/FF
A2000 Blizzard 060 CV/3D
 

Offline TatsuTopic starter

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Re: A2000 Rev.6 Only 512kb showing up
« Reply #4 on: November 22, 2010, 12:29:11 AM »
No progress. J101, j500, j900, j206 nothing changes the status of the memory in any configuration. Exept maybe J101 in 2-3, and J500 closed. Then the computer refuses to start at all.
But in Your link You claim to at least have the extra 512kb visible. I can only see 512kb chip, nothing more what so ever. It is like the extra 512kb is not detected at all. In showconfig only 0,5MEG chip at $400-$7ffff is showing, nothing else. All of the eight memory chips has the same voltage to them at least, about 4.4 volt. I am not sure wich component(s) should tell the system of the existing memory.
A1200T PPC/060 Voodoo5 SD/FF
A2000 Blizzard 060 CV/3D