Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!pasteur!ucbvax!UIAMVS.BITNET!AWCTTYPA
From: AWCTTYPA@UIAMVS.BITNET ("David A. Lyons")
Newsgroups: comp.sys.apple
Subject: RESET on different Apple IIs
Message-ID: <8804221246.aa00788@SMOKE.BRL.ARPA>
Date: 23 Apr 88 05:31:31 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 32
X-Unparsable-Date: Friday 22 Apr 88 11:38 AM CT


>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