oddjob@oz.plymouth.edu (Andrew C. Stoffel) (03/01/91)
In article <1991Mar1.121834.22722@ux1.cso.uiuc.edu> you write: >I took a 1040STf (revision c, with ram UNDER the power supply) and upgraded >it from 1024K to 2.5M in about 4hours for about $80. I used two 1M SIMMs, >1 resistor and a bunch of short pieces of wire. You can go from 512 to >1024 by just dropping in 16 more of the dram chips you already have, but >2.5M is much nicer. Should I post a pin mapping (SIMM to motherboard)? > >Memorably, >Bill Magro Please :-) (I've got a rev. B 1040STf..... hopefully it is close enough :-) Andy (ps. I tried to reply directly but the address bounced......) -- |"The Snark WAS a Boojum, you see!"|Good : acs@unhd.unh.edu | |"Reality !?! Isn't that something |Better : ANDYS@psc.plymouth.edu | | you sprinkle on ice ??" |Best : oddjob@oz.plymouth.edu |
johnj@hijg.prl.philips.nl (John Janssen) (03/04/91)
In article <1991Mar1.144938.26463@oz.plymouth.edu> oddjob@oz.plymouth.edu (Andrew C. Stoffel) writes: >In article <1991Mar1.121834.22722@ux1.cso.uiuc.edu> you write: >>I took a 1040STf (revision c, with ram UNDER the power supply) and upgraded >>it from 1024K to 2.5M in about 4hours for about $80. I used two 1M SIMMs, >>1 resistor and a bunch of short pieces of wire. You can go from 512 to >>1024 by just dropping in 16 more of the dram chips you already have, but >>2.5M is much nicer. Should I post a pin mapping (SIMM to motherboard)? >> >>Memorably, >>Bill Magro >Please :-) (I've got a rev. B 1040STf..... hopefully it is close >enough :-) > >Andy > Where is the resistor for? I like to update my 520+ (1MByte, officially piggy packed by Atari Benelux) but I found one problem. I bought the Xtra ram 2.5 MByte update, which includes descriptions for all kind of difference versions of 520/1040/MegaST, except for mine. I think this is because the 520+ was not sold in GB where Xtra ram comes from. The problem I have is that the documentation described about disconnection two resistors and connecting them to some capicitor in the edge of the PCB. But I do not find these resistors. I found that the CAS and RAS lines (3 wires) are directly coupled from the RAM pins to the MMU. Although the Xtra documentation is very good in "what to do", however, it doesnot say "why". For this reason I'm not sure what to do, and I certainly donot want to blow any of the expensive chips (like MMU). Any help? Thanks. -- John Janssen Note, my address may change constantly priv: +31 77 513177 So please reply via newsnet. Venlo, Holland work: johnj@idms.prl.philips.nl (if you still want to try).