tmp@doc.ic.ac.uk (Trevor Peacock) (10/30/90)
In my never ending quest for memory (without the price :^) I tried a simple experiment on my ST. What I did was to remove the 8 highest bits from bank 1 in my ST and wire up a SIMM socket so that the corresponding data, address, cas, ras & write lines went to those which the 41256's had occupied. I triple checked this, plugged a 256k SIMM into the socket, powered up and... BINGO!! the ST couldn't see the top bank. I plugged the original 41256s back and then powered up to find that the top bank was there again. The SIMM was a 256k * 8 150nS (the original 41256s are 150nS). I was hoping to find that this works, so that I could wire it all up and buy some 1M SIMMs to plug in (with A9 wired up of course). As I understand it, the SIMM should be equivalent to the 8 41256s, except that the address, cas, ras & write lines are tied in parallel. I kept the wires as short as possible etc, so I don't think that this was the problem. Does anyone else have any experience with this - or any suggestions why it didn't work? Trev.. ------------------------------------------------------------------------------- Trevor Peacock, | Tel : 071 589 5111 X 5052 | JANET : tmp@uk.ac.ic.doc Department of Computing, | DARPA : tmp@doc.ic.ac.uk Imperial College, \ or tmp%uk.ac.ic.doc@nsfnet-relay.ac.uk 180 Queens Gate,London SW7 2BZ | UUCP : tmp@icdoc.UUCP or ..!ukc!icdoc!
don@milton.u.washington.edu (Don Clifton) (10/31/90)
In article <2408@gould.doc.ic.ac.uk> tmp@doc.ic.ac.uk (Trevor Peacock) writes: > >I was hoping to... >buy some 1M SIMMs to plug in (with A9 wired up of course). > >Does anyone else have any experience with this - or any suggestions why it >didn't work? > Several months ago I removed 16 of the 256k RAM chips from my 1040, wired in a SIMM dual SIMM socket, and inserted 2 1Meg (80ns) SIMMs. I now have 2.5Megs of memory that works great! I don't know what you did wrong, but it should work.
stigvi@Siri.Unit.NO (Stig Vidar Hovland) (11/02/90)
In article <2408@gould.doc.ic.ac.uk>, tmp@doc.ic.ac.uk (Trevor Peacock) writes: |> |> In my never ending quest for memory (without the price :^) I tried a simple |> experiment on my ST. |> |> What I did was to remove the 8 highest bits from bank 1 in my ST and wire up |> a SIMM socket so that the corresponding data, address, cas, ras & write lines |> went to those which the 41256's had occupied. |> I triple checked this, plugged a 256k SIMM into the socket, powered up and... |> BINGO!! the ST couldn't see the top bank. |> |> |> ------------------------------------------------------------------------------- |> Trevor Peacock, | Tel : 071 589 5111 X 5052 | JANET : tmp@uk.ac.ic.doc |> Department of Computing, | DARPA : tmp@doc.ic.ac.uk |> Imperial College, \ or tmp%uk.ac.ic.doc@nsfnet-relay.ac.uk |> 180 Queens Gate,London SW7 2BZ | UUCP : tmp@icdoc.UUCP or ..!ukc!icdoc! I have just wired up 2 1MB SIMMs in my 520STF, and together with the old memory my ST have a total of 2.5MB. I used SIMMs with a 9bit databus, but 2 8bit SIMMs should work fine too. You must have done something wrong. Maybe you should triple check it twice. Stig Vidar Hovland - stigvi@siri.unit.no
ant@mks.com (Anthony Howe) (11/02/90)
Q: Is there a similar expansion for a MEGA 2 to 4?? Something clean and easy
for a software techno type. And yes I can handle a soldering iron.
-ant
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