viljanen@cs.Helsinki.FI (Lea Viljanen) (10/18/89)
Is there a trick to installing TOS 1.4 into Mega 2's? I know a guy who has installed several ROM sets into all kinds of ST's (520 ST - Mega 4). But only with Mega 2's he has problems; only 1 machine worked from the 6 he has done. Other types (even Mega 4's!) have worked OK. So, who knows what's the crucial difference between Mega 2 and Mega 4 so the same installing procedure doesn't work with Mega 2 but works with Mega 4? Any help appreciated. -- """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" Lea 'LadyBug' Viljanen ____ University of Helsinki, Finland viljanen@finuha.bitnet \ / . ' Dept. of Computer Science viljanen@cs.helsinki.fi \/ |_ 'I hate Sun & dbx'
larserio@IFI.UIO.NO (LarsErikOsterud) (10/19/89)
There are som MEGA ST 2's with the ROM's at another adress than $FC0000. The univeristy in Oslo has 50/50 of these and the "normal" MEGA ST 2's, and on the "strange" type many programs won't work because they THINK the ROM's is at $FC0000 (of course the ROM MAY be located anywhere but not all follows Atari's standards..) Maybe TOS 1.4 has the same trouble ? Lars-Erik / ABK-BBS +47 2132659 / ____ ______ ________________________ Osterud / larserio@ifi.uio.no / /___ / The norwegian ST __________/ ______________________/ ____/ / Klubben, user association
covertr@force.UUCP (Richard E. Covert) (10/19/89)
In article <2706@hydra.Helsinki.FI>, viljanen@cs.Helsinki.FI (Lea Viljanen) writes: > Is there a trick to installing TOS 1.4 into Mega 2's? > I know a guy who has installed several ROM sets into all kinds of > ST's (520 ST - Mega 4). But only with Mega 2's he has problems; > only 1 machine worked from the 6 he has done. Other types (even Mega > 4's!) have worked OK. > > So, who knows what's the crucial difference between Mega 2 and Mega 4 > so the same installing procedure doesn't work with Mega 2 but works > with Mega 4? > > Any help appreciated. > Lea 'LadyBug' Viljanen ____ University of Helsinki, Finland Lea, there is a problem with replacing the 2 chip TOS 1.2 with a 6 chip TOS 1.4. In some, not all but enough, Mega STs you need to replace the 74LS373 ics with 74 AS 373. repeat place the LS with AS. AS have a higher fan out and can drive the additional load presented by the additional 4 EPROMS. This is a kludge and is known by Atari, but it has to been done when you install the new TOS if they fail. Good luck.. Richard (Thw Whiner (tm) ) Covert