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03.011 Is it possible to set up a simple ProDOS-8 application (SYS) file which turns the ZipGS OFF or ON?




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This article is from the Apple II Csa2 FAQ, by Jeff Hurlburt with numerous contributions by others.

03.011 Is it possible to set up a simple ProDOS-8 application (SYS) file which turns the ZipGS OFF or ON?

    From the usual BASIC prompt, get into the Monitor (e.g. CALL -151) and type in
the following code to turn OFF the ZipGS ...

2000:A9 50 8D 5A C0 8D 5A C0 8D 5A C0 8D 5A C0 8E 5A
2010:C0 0A 8D 5A C0 20 00 BF 65 1D 20 00 00 04 00 00
2020:00 00 00 00

A 2000L should look something like this ...

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 ZIP
2011: 0A       ASL                = SLOW mode
2012: 8D 5A C0 STA  $C05A     ; write $A0 to stop accessing 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

Use the following commands to save it:

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

To enable the ZipGS (= FAST mode), simply change one byte:

200F:5B

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

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

By:  William Baguhn

Reference: FAQs resource file R005SPLITC.GIF (pic file)
    

 

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