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Source for Model 4p (GA) RAM?
- Thread starter K5XS
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deathshadow
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That's going to be 4164's, which Jameco always has in stock for a buck a pop. You might be able to find cheaper, but Jameco is a known quantity.
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_41662_-1
It's what I used to bring my 4p back up to 128k -- I briefly downgraded it to 64k to bring my Coco 1 up to 64k, since the rev NC board in the Coco also takes 4164's.
I'd suggest grabbing 16-20 of them -- it never hurts to have spares given how often old RAM's go wonky... besides it costs $8 for 8 of them, and $9 for ten of them...
That reminds me, I've got a stack of 16K coco's sitting here waiting for memory upgrades, ROM upgrades and resale. (Got a deal on a STACK of 16k standard color basic units)
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_41662_-1
It's what I used to bring my 4p back up to 128k -- I briefly downgraded it to 64k to bring my Coco 1 up to 64k, since the rev NC board in the Coco also takes 4164's.
I'd suggest grabbing 16-20 of them -- it never hurts to have spares given how often old RAM's go wonky... besides it costs $8 for 8 of them, and $9 for ten of them...
That reminds me, I've got a stack of 16K coco's sitting here waiting for memory upgrades, ROM upgrades and resale. (Got a deal on a STACK of 16k standard color basic units)
Lorne
Veteran Member
I recently upgraded my Model 4 (non-gate array version) to 128K, but along with the RAM it also needed a PAL chip.
The manual called for a Tandy # 8075468 IC as part of the 128K upgrade, while the PAL that I pulled from another upgraded non-gate array version model 4 machine was labelled as a Tandy PAL16L8CN 833IV.
You sure you don't need a PAL chip as well, or is the 4P gate array version a different beast?
The manual called for a Tandy # 8075468 IC as part of the 128K upgrade, while the PAL that I pulled from another upgraded non-gate array version model 4 machine was labelled as a Tandy PAL16L8CN 833IV.
You sure you don't need a PAL chip as well, or is the 4P gate array version a different beast?
deathshadow
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Mine didn't need it, but mine was 128 to start with. One easy way to tell, does it have 8 empty sockets or nine? Is that 9th one 20 pin?
A PAL16L8 should be a PAL16L8, not a lot of variation, input pins one through nine and 11, ground pin 10, output on 12 and 19, I/O on pins 13 through 18, power pin 20.
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_28020_-1
Should do the job, though you should compare the data sheet for the tandy one (if you can find it) to be sure.
A PAL16L8 should be a PAL16L8, not a lot of variation, input pins one through nine and 11, ground pin 10, output on 12 and 19, I/O on pins 13 through 18, power pin 20.
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_28020_-1
Should do the job, though you should compare the data sheet for the tandy one (if you can find it) to be sure.
Druid6900
Veteran Member
Actually, in a way you are correct. A PAL16L8 is a PAL16L8, until they are programmed. PAL stands for Programmable Array Logic and were used to custom design chips that didn't exist at the time by burning out fuse links internally. After that, they were a whole different critter.
It may well be that, with some PALs, you could drop them in a chip tester and it would come up as some commonly available chip (now) that didn't exist then. Someday I'll have to try a few and see if they are recognized as anything.