jfbruno@rodan.acs.syr.edu (John Bruno) (12/20/90)
In article <1990Dec16.102842.66@n6vbg.hamavnet.com> system@n6vbg.hamavnet.com writes: >Hello everyone, > >I'm thinking about adding some more memory to my 1040ST, and I was >wondering if those of you who have done so in the past would share their >experiences here. Is there any recommendations as to what products are >reliable and which ones are not (i.e., Zram, JRI, etc). > >Thanks, > >-- >Javier Henderson, N6VBG > >system@n6vbg.hamavnet.com >{simpact,asylum,elroy}!hamavnet!n6vbg!system Here's a repost of my repost on installing the JRI SIMMs board. I installed 4MB in my 1040ST. Everything works, the memory is usable with Spectre and everything else. Once in a while, the 1040 has problems booting, but if I lift it slightly off the desk and drop it, it works fine. Note that the prices I have quoted are much cheaper now, probably $35-40 or so (for the SIMMs) ---jb ----------------------- Here's a summary of my recent adventure expanding my ST's RAM to 4MB using the JRI SIMMs board. John Russell Innovations PO Box 5277 Pittsburg, CA 94565 (415) 458-9577 I bought 4MB of 1MBx8 80NS SIMMs from some vendor (I forget) but browsing through the current MacWeek, I found the PSI ad: PSI, Inc. (800) 622-1722, for $59.50 per MB, you defintely need low profile SIMMS. By the way, the JRI board was $125, so the whole thing can be done for about $350-400. Here's how it went for me: The JRI kit arrived and even included some jumper wires and some solder! There are 4 different sets of instructions that you must choose from, depending on your particular ST's motherboard (works for 520STs also, by the way). The differences between the boards are clearly shown. I found that the instructions were a little vague about a couple of things, for example, the instructions keep refering to top,bottom,left,right sides of the shifter board when the proper orientation of the board is never shown. Basically you have to remove 6 resistors from the motherboard (only 3 if you're just going to 2.5MB) and put in a total of about 10 jumper wires, one of which is a pain because it is a jumper to pin 61 of the MMU, which must be soldered UNDERNEATH the motherboard and then attached to the JRI board. I had a couple of problems with the upgrade, first problem was that the jumper to the MMU that runs under the motherboard got shorted by some of the soldering points under the ST. I solved this by using electrical tape to stick the jumper to the backside of the motherboard in safe fashion. You also have to remove the Shifter chip, which is inside a square tin housing. You then put the chip on a supplied board, which then goes into the socket (thank god a socket was used!) left by the now vacant Shifter. This board has space for 2 shifter chips, which means that if you buy the optional second shifter (can get them at any Atari service place, I guess) you can get 4096 colors instead of the 512 on a regular ST (I haven't done this yet) Anyway, I accidentally plugged the shifter board in wrong, it's difficult to see what you're doing here--not much space. Next problem was that the bottom of the shifter board was shorting out with other components underneath it. I used more tape to fix this. This problem was weird because the machine worked in monochrome, but would bomb out in color. Luckily, I figured it out. Oh, by the way, I noticed the problem with the shorted MMU jumper because the machine only recognized 1MB of RAM. The third problem was where to put the board and still be able to shut the ST's case. I found the best way was to run all the wires through the shield that goes over the power supply (I had to bend the shield for this) and lay the board between the power supply shield and disk drive ABOVE the big tin shield. I put the board in a plastic bag to hopefully avoid any moisture or spill problems. All in all, the thing works!!! The instructions were a little vague in the areas I touched on above, and I wouldn't recommend doing the upgrade unless you are willing to rip your machine apart. A couple of times I thought I had broken my machine, but carefully going over all of the connections helped me find all of the problems. By the way, you only need 120NS SIMMs, not the faster ones I got, but the savings for the slow SIMMs are probably minimal. Good luck if you decide to go for it! ---jb