achowe@tiger.waterloo.edu (anthony howe) (11/09/89)
[...] >The solution appears to be to remove to 'weak' 74LS373 chips and replacing >them with stronger 74AS373 chips. My machine will probably go for a trip >to have this work done (in addition to a RAM upgrade) I'll let you know >what happens. >Peter Szymonik Does anyone know how many of these chips are on the machine and what their location names are? - ant achowe@tiger.waterloo.edu | "It is hard to make the world go away _ -|-|_ _ | when it has decided to notice you." (_\ |\| | | | (_) |\| \/ | - Spock's World ___/ | disclaimer...
achowe@tiger.waterloo.edu (anthony howe) (11/09/89)
[...] >Messages from James Allen (of FAST Technologies) on Genie have >recommended replacing 74ls373 chips with 74as373 chips, and if >you still have problems, start swapping MMU chips (especially if >you have one labeled "imp"). > >dgc Are the MMU chips generic and commerically available or are they Atari Custom Brand? - ant achowe@tiger.waterloo.edu | "It is hard to make the world go away _ -|-|_ _ | when it has decided to notice you." (_\ |\| | | | (_) |\| \/ | - Spock's World ___/ | disclaimer...
stank@anvil.WV.TEK.COM (Stan Kalinowski) (11/10/89)
In article <1989Nov8.173612.8571@mentor.com> dclemans@mentor.com (Dave Clemans @ APD x1292) writes: . . . >One problem can come up if you switched from a two chip to a six chip >ROM set. The ST runs right at (or above...) the upper margins of the >drive capability of some of the buffer chips. If you happened to have >weak buffer chips (particularly the two 74ls373 chips) or a weak >memory controller chip (the MMU; chips stamped with "imp" especially As a proud new owner of the TOS 1.4 ROM set, I'm a little apprehensive about installing them given all this talk about weak drivers and such. (I'm also lazy.) I hit upon the idea of copying the TOS roms into a PROM programmer and making a higher density, 2-ROM chip from the 6-ROM set that I bought. It seems like it should be fairly straignt forward. I should be OK from a copyright/legal standpoint as long as I continue to hang on to my original 6 ROM set. (I believe this would be equivalent to making a backup copy.) What I need to know is what is the common device number used for the 6-ROM set, what is the common device number for the 2-ROM set, and is there a pin compatible EPROM version of the 2-ROM device number. I could try to stare at the PC board and figure it out myself, or better, try to find a schematic, but I though I'd ask here because I suspect some people may know off-hand. stank PS: It just occurred to me that this whole plan could backfire if the total amount of code stored in the 6-ROM set is larger than the size of the higher density ROMs, perhaps this is why nobody has discussed this idea here. If this is the case, it will become obvious to me once I know what the part numbers are. For now, I presume Atari went with the lower density parts because they were cheaper. US Mail: Stan Kalinowski, Tektronix, Inc., Interactive Technologies Division PO Box 1000, MS 61-028, Wilsonville OR 97070 Phone:(503)-685-2458 e-mail: {ucbvax,decvax,allegra,uw-beaver}!tektronix!orca!stank or stank@orca.WV.TEK.COM
verwer@ruuinf.cs.ruu.nl (Nico Verwer) (11/10/89)
In article <5286@orca.WV.TEK.COM>, stank@anvil.WV.TEK.COM (Stan Kalinowski) writes: > I hit upon the idea of copying the TOS roms into a > PROM programmer and making a higher density, 2-ROM chip from the 6-ROM > set that I bought. It seems like it should be fairly straignt > forward. I should be OK from a copyright/legal standpoint as long as I think this is impossible, for the following reason: The ROMs in a mega-ST have a standard pinout. All pins are used on these ROMs. An EPROM needs an extra pin (Vpp) in order to program it, and with this standard pinout, there is just no spare pin left for this function. So I am afraid you will not be able to find EPROMs which can be used as an equivalent for the 2-ROM set.
Xorg@cup.portal.com (Peter Ted Szymonik) (11/13/89)
There are two LS373's that have to be replaced (and good luck trying to find the damn chips! <grin>) there are located right next to the RAM in the middle of the board. I've also been told that some MMU chips also suffer from the same problem, I *think* they are the ones marked 'inf' Peter Szymonik Xorg@cup.portal.com
andyc@hplsla.HP.COM (Andy Cassino) (11/16/89)
|There are two LS373's that have to be replaced (and good luck trying |to find the damn chips! <grin>) there are located right next to the |RAM in the middle of the board. I've also been told that some MMU |chips also suffer from the same problem, I *think* they are the ones |marked 'inf' | |Peter Szymonik |Xorg@cup.portal.com |---------- Thanks everyone for the info. It seems like the best approach is to replace the LS373's with 74AS373's to insure there will always be plenty of drive. The latter have *plenty* of poop. I'm trying to locate some now and will report back. Disclaimer: The opinions expressed herein are those solely of the author, who has no pecuniary interest in the companies mentioned. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Andy Cassino % % uucp: hplabs!hplsla!andyc domain: andyc%hplsla@hplabs.hp.com % % Hewlett-Packard Lake Stevens Instrument Division % % 8600 Soper Hill Road Everett, WA 98205-1298 % % (206) 335-2211 % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Xorg@cup.portal.com (Peter Ted Szymonik) (11/18/89)
Hi guys, I just got my newly upgarded Mega 2 (now with 4 megs of RAM and the new AS chips - I'll do extensive tests and report back!) Peter Szymonik Xorg@cup.portal.com
andyc@hplsla.HP.COM (Andy Cassino) (11/30/89)
Well, I got my Mega ST2 back from the dealer yesterday with newly installed
74AS373 drivers and the bus/address error problem seems to be fixed. The
dealer ran my computer two days on the showroom floor with no problem,
and I was unable to create any problems at home.
It looks like I'm a happy camper once again!
Disclaimer: The opinions expressed herein are those solely of the author,
who has no pecuniary interest in the companies, products,
or publications mentioned above.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Andy Cassino %
% uucp: hplabs!hplsla!andyc domain: andyc%hplsla@hplabs.hp.com %
% Hewlett-Packard Lake Stevens Instrument Division %
% 8600 Soper Hill Road Everett, WA 98205-1298 %
% (206) 335-2211 %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%