v104nmym@ubvmsb.cc.buffalo.edu (Sherman T Chan) (04/18/91)
A few years back, I bought a upgrade kit for the 600XL which consisted of two chips which replaced the on board 16K rams and a bunch of jumpers to rewire the MMU. I replaced the chips , but shortly afterwards I lost the jumpers and instructions. Has anyone done this mod before, and either remember what pins to connect the jumpers between, or do you still have the instructions from a kit you might have purchased? any help would be appreciated. Thanks in advance. Sherm
ken@hpcupt3.cup.hp.com (Kenneth M. Sumrall) (04/21/91)
>A few years back, I bought a upgrade kit for the 600XL which >consisted of two chips which replaced the on board 16K rams >and a bunch of jumpers to rewire the MMU. I replaced the >chips , but shortly afterwards I lost the jumpers and instructions. > >Has anyone done this mod before, and either remember what pins to >connect the jumpers between, or do you still have the instructions >from a kit you might have purchased? >any help would be appreciated. >Thanks in advance. > I designed my own 64K mod for the 600XL back in 1987. It requires two 64Kx4 ram chips, and three jumper wires. Here it is. HOW TO UPGRADE YOUR ATARI 600XL TO 64K RAM THIS MOD IS COPYRIGHTED BY KEN SUMRALL. HOWEVER, YOU MAY FREELY DISTRIBUTE IT, AND MODIFY IT, AS LONG AS THIS NOTICE IS INCLUDED IN ITS ENTIRERTY. THE AUTHOR MAY BE REACHED AT THE FOLLOWING EMAIL ADDRESSES: ken%hpda@hplabs.hp.com ...!hplabs!hpda!ken You will need the follow parts to perform this mod: (2) 4464 RAM chip, 64Kx4, 150ns or faster. Additionally, you will need chip pullers, a soldering iron, and 3 small pieces of wire. I used wire wrap wire when I did this mod. If the chips on your 600XL are socketed, you're in luck, otherwise, you need to first unsolder the following chips: (1) 74S32 location U18 (2) 74LS158 locations U5 and U6 (2) 4416 locations U11 and U12 and put sockets on the mother board in their place to make the job easier. Now bend up pin 9 on the 74S32, and put it back in its socket on the mother board. Bend up pin 3 on the 74LS158 in location U5, and put it back in its socket. Also, bend up pin 10 on the 74LS158 in location U6, and put that chip back into its socket. The last two chips you need to change are the two RAM chips. Put the 4464 chips into the sockets at locations U11 and U12 on the motherboard. Now you need to install 3 wires to complete the mod. The first wire should be connected between pin 3 of the 74LS158 at location U5, and pin 20 of the parallel bus on the 600XL. The second wire should be connected between pin 10 of the 74LS158 at location U6, and pin 18 of the parallel bus. The third wire connects between pin 9 of the 74S32 at location U18, and pin 45 on the parallel bus. That's all there is to it.
v104nmym@ubvmsd.cc.buffalo.edu (Sherman T Chan) (04/22/91)
In article <48510005@hpcupt3.cup.hp.com>, ken@hpcupt3.cup.hp.com (Kenneth M. Sumrall) writes... >I designed my own 64K mod for the 600XL back in 1987. It requires >two 64Kx4 ram chips, and three jumper wires. Here it is. > > [instructions for mod deleted] Thanks for the tips, but I've got one problem...how do i know which pin is which? That's the reason why I put off on doing it years ago, and then I just let it sit for so long that I lost it. So could you mail me, or post to the net on how to figure out what pins are what? Thanks, Sherm
mwoodwar@yoda.eecs.wsu.edu (woodward matthew d - CS350) (04/23/91)
In article <72272@eerie.acsu.Buffalo.EDU> v104nmym@ubvmsd.cc.buffalo.edu writes: >In article <48510005@hpcupt3.cup.hp.com>, ken@hpcupt3.cup.hp.com (Kenneth M. Sumrall) writes... >>I designed my own 64K mod for the 600XL back in 1987. It requires >>two 64Kx4 ram chips, and three jumper wires. Here it is. >> >> >[instructions for mod deleted] >Thanks for the tips, but I've got one problem...how do i know which pin is which? That's the reason why I put off on doing it years ago, and then >I just let it sit for so long that I lost it. >So could you mail me, or post to the net on how to figure out what >pins are what? Thanks, Look at the IC so the notch on a narrow end is at the top. The pins are then numbered counter-clockwise from the notch. (Go down the left side, then up the right) Matt >Sherm