paryavi@harris.cis.ksu.edu (Saiid Paryavi) (10/26/89)
This would probably only interest hardware hackers ...
I opened up an old 512KE Mac to see what the DRAM chips were. I found out
that there are 2 rows of 8 socketed chips in each row. The chips are 256K bit
DRAM chips.
What I am wondering about is if it is possible to just take those 256K bit
chips out and plug in 1 Mbit DRAM chips to upgrade the RAM to 1 meg!!!!
Any ideas?
--
Saiid Paryavi Computer Science Dept.
Internet: paryavi@harris.cis.ksu.edu Nichols Hall
BITNET: paryavi@ksuvax1.bitnet Kansas State University
UUCP: {rutgers, texbell}!ksuvax1!harry!paryavi Manhattan, KS 66506fjo@cbnewsc.ATT.COM (frank.j.owen) (10/28/89)
From article <4338@deimos.cis.ksu.edu>, by paryavi@harris.cis.ksu.edu (Saiid Paryavi): > This would probably only interest hardware hackers ... > > I opened up an old 512KE Mac to see what the DRAM chips were. I found out > that there are 2 rows of 8 socketed chips in each row. The chips are 256K bit > DRAM chips. > > What I am wondering about is if it is possible to just take those 256K bit > chips out and plug in 1 Mbit DRAM chips to upgrade the RAM to 1 meg!!!! Well, the big problem is that the 256K parts have fewer pins than the 1 Meg parts. You would have to provide more address lines. (and address multiplexors for the address lines.) It would be a pretty involved hack to do this. Also, the 1 Meg parts are physically larger, so I'm not so sure you'd be able to physically cram them into the space that had been provided for the 256K parts. You'd probably be better off getting one of the 3rd party memory upgrades. They can sometimes be bundled with a SCSI port, which converts your 512KE functionally to a MacPlus. BTW, if you did replace the 256K parts with 1Meg parts, you would end up with 2 Megabytes. -- Frank Owen 312-982-2182 AT&T Bell Laboratories 5555 Touhy Ave., Skokie, IL 60077 PATH: ...!att!ihc!fjo