Closed A500 DRAM chips or Broken A500 mobos

[DelboyJay]

Hi People,

I'm looking for 16 dram chips for an A500 Rev 6A mobo. If you have a dead rev 6A mobo that I could have on the cheap that would be coolio.

Cheers,

DelboyJay

 

[Zetr0]

@DelboyJay

16 dram chips? for the Rev5 6a?

thats enough to completely replopulate two complete motherboards, or populate 4 standard Rev6A boards.

why so many if you don't mind me asking?

 

[rkauer]

Or are you planning to populate a 2091 card/A3000(T)/A590? Prefer to buy new chips as the remaining solder may hurt the card's sockets.

16 chips have 2Mb of RAM.

 

[BLTCON0]

@DelboyJay

16 dram chips? for the Rev5 6a?

thats enough to completely replopulate two complete motherboards, or populate 4 standard Rev6A boards.

why so many if you don't mind me asking?

Wasn't there somewhere a guide for 2 MB chip ram that involved piggybacking of the RAM chips?
Although that would imply another 12 chips were needed but 16 surely works too.

 

[rkauer]

Not on the rev6 A500, mate. The hack is intended for rev6.x A2000 units.

I was after a suitable (A3000) Agnus to validate the hack for the rev6 A500 but the 8372AB Agnus chips I found was way too expensive to bought.

Of course you can solder another 512kb (4 chips) to the rev6 mobo and do a cut&join hack to have 1Mb chip RAM with no trapdoor card, as I did on two of mine rev6 A500.

 

[BLTCON0]

Probably so. Thinking more about it, it was piggybacking another 8 chips on an A500+ board for a total of 2 mb chip RAM. I even think it was on Cosmos' blogsite?
I've done the cut&solder hack but I still use the trapdoor RAM board for the extra 0.5 mb chip RAM, so I won't lose the RTC. Funny thing is my rev6A actually has empty holes, not solder-filled ones, for the missing RAM chips, it's like an invitation to solder chips there

 

[rkauer]

Use sockets, please.

One bad RAM chip can be a nightmare to spot and sacking it off may be a prove of patience.:banghead:

 

[Skellionz]

:hijacked:

 

[DelboyJay]

I totally forgot about this thread sorry guys.

I managed to get hold of these I'm upgrading some 6A mobos to 1mb and I'm also looking at doing a little memory project for the Amiga hence the number of chips required.

I didn't use sockets on the first board... I had a problem... found out there was a strad of wire from my desolfer braid that managed to connect itself to two of the legs of one of the original memory chips! All is fine now.

My only problem is that the A501 card no longer works. I'm trying to get a schematic for it but I think that it is mapping to the same memory as the chip ram upgrade or it could be due to the fact that JP7A is completely open which I don't think is right so going to check up on that.

If I find anything out i'll post a new thread with some details.

Thanks for watching.

Delboy

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-=MODS=- please change prefix to Found.

 

[rkauer]

Yes, the A501 will be redundant to the soldered extra 512kb, so no use for it.

Me & Zetr0 (among other awesome people) are still struggling to find a way to add the A501 as a ranger memory (address C80000) aka fake-FAST RAM and keep using the on-board soldered chips. That without heavily board modification.