chad@byuvax.bitnet (01/23/88)
meg upgrade for 520stfm? I recently bought a 520STFM and would like any information on how to upgrade to 1meg on board (a do it yourself type job with chips and sockets). We opened it up and looked at the mother board and all the lines appear to be there for the next 512K like it is in a 1040. Besides the chips, are there any jumpers to make, change, etc.? I would appreciate any info (mail to me) on how to do this. Thanks. Chad BITNET: CHAD@BYUVAX
rich@lakesys.UUCP (01/24/88)
In article <87chad@byuvax.bitnet> chad@byuvax.bitnet writes: >meg upgrade for 520stfm? > > >I recently bought a 520STFM and would like any information on >how to upgrade to 1meg on board (a do it yourself type job with chips >and sockets). We opened it up and looked at the mother board and >all the lines appear to be there for the next 512K like it is in a >1040. Besides the chips, are there any jumpers to make, change, etc.? > >I would appreciate any info (mail to me) on how to do this. >Thanks. > >Chad > >BITNET: CHAD@BYUVAX I just completed another upgrade of the 520STfm machine. This last machine was a revision D mother board. The only things that you need are 16) 256 by 1 Drams (200 ns ( 150 ns is better )) 16) Sockets for these (if you want to socket them) 16) .22Uf 25wv Ceramic Caps. I use the easy mans means to make the mod in short order but you may not have the tools that I use. I would suggest however, that you find someone who may, and try and borrow it. Makes life alot easier than the solderWick method that i'v heard others use. By this I mean, try and get a small PC board drill. I used a Wahl Iso*Tip quick charge pen with a drill attachment. The size drill I used was a .0330 Dia bit. Then I just proceded to drill the closed holes open. This way I left some of the solder still there and and did not run the chance of overheating the PC Board foils so as to have them lift up. (Bummer when they do that) Insert the sockets and solder in, then insert the Caps and solder in, then finally pop the Drams in the sockets. Thats about all there is to it. I used a 700 degree isolated, temprature controlled soldering station, but the main drift here is not to use any more heat than needed. Assemble the machine, less the rf sheild (until you know it's working correctly) and boot up. Either run one of the Ram Check programs OR just a simple P/D Ramdisk program, and create a 600K ramdisk. If you got all the solder connections correct, you have it made. If you cannot create the ramdisk, then check to make sure that the connectoins are all there. The machine will still boot (unless you really have something screwed up) as the first bank you never touched. I payed $89.00 for 16 NEC Drams, $24.00 for the sockets, and $4.?? for the caps. Took 1 hour 50 minutes to complete the job, though if your not as experienced as I, take your time. One mistake, and you could be out a whole machine! -rich..... UUCP: {Ihnp4,uwvax}!uwmcsd1!lakesys!rich Discalimer: The words,ideas,and expressions are my own, and not nessasarily always correct ! I'll tell you how, its up to you to get it right....