Path: ns-mx!hobbes.physics.uiowa.edu!moe.ksu.ksu.edu!zaphod.mps.ohio-state.edu!wupost!waikato.ac.nz!comp.vuw.ac.nz!actrix!David.Empson
From: David.Empson@actrix.gen.nz (David Empson)
Newsgroups: comp.sys.apple2
Subject: Re: Speaking of the Zip...
Message-ID: <1991Nov13.121010.18813@actrix.gen.nz>
Date: 13 Nov 91 12:10:10 GMT
References: <1991Nov11.185126.28247@usenet.ins.cwru.edu> <1991Nov12.135052.365@actrix.gen.nz>
Organization: Actrix Information Exchange, Wellington, New Zealand
Lines: 42
Comment-To: David.Empson@actrix.gen.nz

Sorry, slight error in my previous posting on this subject: the
ProDOS-8 QUIT call parameter block has too few zeros in it.  The
correct program should read:

2000: A9 50	LDA	#$50
2002: 8D 5A C0	STA	$C05A	; write $50 to $C05A four times to
2005: 8D 5A C0	STA	$C05A	; enable access to the ZIP registers
2008: 8D 5A C0	STA	$C05A
200B: 8D 5A C0	STA	$C05A
200E: 8E 5A C0	STZ	$C05A	; write $00 to $C05A to disable the ZIP
2011: 0A	ASL
2012: 8D 5A C0	STA	$C05A	; write $A0 to stop accessing the ZIP
2015: 20 00 BF	JSR	$BF00	; Do a ProDOS QUIT call
2018: 65		$65
2019: 1D 20		$201D
201B: 00 00	BRK	$00
201D: 04 00 00 00 00 00 00

Just type in the hex codes on the left, and use the following commands
to save it:

CREATE SLOW,TSYS
BSAVE SLOW,TSYS,A$2000,L$24


To write FAST, simply change one byte:

200F:5B

(this changes the STZ $C05A to STZ $C05B)

CREATE FAST,TSYS
BSAVE FAST,TSYS,A$2000,L$24


Sorry about that.  It wouldn't affect the program at all, but might
cause compatibility problems with future versions of ProDOS.
-- 
David Empson

EMPSON_D@kosmos.wcc.govt.nz
David.Empson@bbs.actrix.gen.nz