AWCTTYPA@UIAMVS.BITNET ("David A. Lyons") (04/23/88)
>Date: Wed, 20 Apr 88 18:09:00 EST >Reply-To: Info-Apple@BRL.ARPA >From: PGOETZ%LOYVAX.BITNET@CUNYVM.CUNY.EDU >Subject: Reset in different IIs > > I'm disappointed to hear that you can't change the ROM reset vector in >the IIc. >... > So: Can people with manuals or who actually try this tell us on which >IIs reset pulls in the old ROMs? (Actually, this is hard to believe - I >think in the II+, the 6502 Reset line is hard-wired to put the contents >of FFFE and FFFF in the program counter.) > >Phil Goetz >PGOETZ@LOYVAX.bitnet I think every Apple II after the II+ automatically switches to reading ROM before letting the processor do the RESET sequence. Pressing RESET on the II+, //e, and //c does indeed directly pull the 65[c]02's RESET line low, and the effect is the same on the IIgs (it's just less direct: the ADB Microcontroller realizes you're pressing RESET and passes a signal on to the processor [fun experiment: hook up 2 keyboards to your GS; press CTRL on one and RESET on the other--it works!]). By the way, it's $FFFC/D for RESET ($FFFE/F is for IRQ/BRK, and $FFFA/B is NMI). --David A. Lyons a.k.a. DAL Systems PO Box 287 | North Liberty, IA 52317 BITNET: AWCTTYPA@UIAMVS CompuServe: 72177,3233 GEnie mail: D.LYONS2