TRM900@PSUVM.BITNET (Tony R. Marasco) (09/02/88)
I remember seeing an article about expanding the Model III's memory capacity. I was wondering if this same technique could be used to upgrade the Model IV's memory from 64K to 128K. Any help would be appreciated. ------- +-------------------------------------------------------------------------+ | Tony Marasco | UUCP: psuvax1!psucurt!psuvm!trm900 | | Penn State University | BITNET: trm900@psuvm | | Schuylkill Haven Highway | - or - | | Schuylkill Haven, PA 17976 | trm900@psuvm.psu.edu | | "Questions are a burden for others. Answers are a prison for oneself." | | -- The Prisoner | +-------------------------------------------------------------------------+
tif@cpe.UUCP (09/03/88)
Written 2:37 pm Sep 1, 1988 by psuvm.bitnet!trm900 in cpe:comp.sys.tandy >I remember seeing an article about expanding the Model III's memory >capacity. I was wondering if this same technique could be used to upgrade >the Model IV's memory from 64K to 128K. Any help would be appreciated. That may have been a trick on the Model III but it is a standard feature of the Model IV. You just fill the empty sockets with 64Kx1 RAMS and you have to add one jumper (don't remember where). Paul Chamberlain Computer Product Engineering, Tandy Corp. {convex,killer}!ninja!cpe!tif
ditto@cbmvax.UUCP (Michael "Ford" Ditto) (09/03/88)
In article <51640TRM900@PSUVM> TRM900@PSUVM.BITNET (Tony R. Marasco) writes: >I remember seeing an article about expanding the Model III's memory >capacity. I was wondering if this same technique could be used to upgrade >the Model IV's memory from 64K to 128K. Any help would be appreciated. Tandy was especially sleazy with the Model 4 -- they designed it so that it required a PAL change to address 128K. You can order the RAMs and PAL from Radio Shack, or you can buy a "clone" set from several mail-order-type places (I even seem to remember that Jameco sells a set). Or, if you have access to a PAL programmer I have the PAL equations which I used to make my own "homebrew" PAL. I think I used a 16L8 ... I have a hardcopy of the equations somewhere; I can type it in if someone really wants it. The RAMs are 4164s, 150ns. 8 of them are standard, 8 more are needed to have 128K. -- -=] Ford [=- . . (In Real Life: Mike Ditto) . : , ford@kenobi.cts.com This space under construction, ...!ucsd!elgar!ford pardon our dust. ditto@cbmvax.commodore.com
uhclem@trsvax.UUCP (09/06/88)
<> R1>That may have been a trick on the Model III but it is a standard feature R1>of the Model IV. You just fill the empty sockets with 64Kx1 RAMS and R1>you have to add one jumper (don't remember where). Sorry, that is wrong. On the plain Model 4, you MUST have a PAL installed in place of the shunt at U72. If the machine only came with 16K or 64K, a shunt was installed instead of that expensive PAL. The Model 4D and 4P do have a single strap you change to allow 128K. <My opinion, and not that of my employer who is coasting on inventory.> "Thank you, Uh Clem." Frank Durda IV @ <trsvax!uhclem> ...decvax!microsoft!trsvax!uhclem ...sys1!hal6000!trsvax!uhclem I've come to praise ihnp4, not to send mail through him.