Re: Embed binary code in Applesoft program lines

Newsgroups	comp.sys.apple2
Date	2021-07-16 07:55 -0700
References	<mmphosis-1626308395@macgui.com> <451fbd19-b67a-4ed2-872c-0832a4ec3e50n@googlegroups.com> <4cb552cb-b774-49c6-9b44-01dde71ca571n@googlegroups.com> <a057df6b-989a-4e41-ab38-ebb0e288a4aan@googlegroups.com> <alpine.DEB.2.21.2107160908180.9612@sd-119843.dedibox.fr>
Message-ID	<e1c3dc29-6dea-4e48-9cab-3a4aa062ff71n@googlegroups.com> (permalink)
Subject	Re: Embed binary code in Applesoft program lines
From	fadden <thefadden@gmail.com>

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Take a look at RENUMBER from the DOS 3.3 System Master disk.

[...]
 1200  HOME : PRINT  TAB( 4)"RENUMBER IS INSTALLED AND READY"
 1210  VTAB 8: PRINT "IF YOU USE 'FP', 'HIMEM', OR 'MAXFILES'"
 1220  PRINT : PRINT "  YOU WILL HAVE TO RE-RUN RENUMBER"
 10000  REM  DO NOT CHANGE 10010
 10010  CALL  PEEK (121) +  PEEK (122) * 256 + 31

It's looking at $79-7a (OLDTEXT), which holds a pointer to the end of the previous line.  The machine-language code follows the last line, so really the comment should be, "do not change 10010, or add anything after this line".  So long as you follow that rule, you can add or remove lines, and everything just gets moved around.

The code it calls relocates itself below DOS and sets up the ampersand vector.

One reason to use this sort of approach is for programs on cassette tape.  Binary programs must be loaded with an explicit start and length, but BASIC programs can just use LOAD/SAVE.

(For Integer BASIC, see https://retrocomputing.stackexchange.com/q/494/56 .)

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Thread

Embed binary code in Applesoft program lines mmphosis <mmphosis@macgui.com> - 2021-07-15 00:19 +0000
  Re: Embed binary code in Applesoft program lines I am Rob <gids.rs@sasktel.net> - 2021-07-14 23:40 -0700
    Re: Embed binary code in Applesoft program lines Mike Spangler <mspangler@ifiber.tv> - 2021-07-15 13:05 -0700
      Re: Embed binary code in Applesoft program lines Erik Struiksma <eriknoc@gmail.com> - 2021-07-16 03:24 -0700
      Re: Embed binary code in Applesoft program lines Erik Struiksma <eriknoc@gmail.com> - 2021-07-16 03:25 -0700
        Re: Embed binary code in Applesoft program lines Steve Nickolas <usotsuki@buric.co> - 2021-07-16 09:09 -0400
          Re: Embed binary code in Applesoft program lines fadden <thefadden@gmail.com> - 2021-07-16 07:55 -0700
            Re: Embed binary code in Applesoft program lines Erik Struiksma <eriknoc@gmail.com> - 2021-07-16 19:05 -0700
  Re: Embed binary code in Applesoft program lines mmphosis <mmphosis@macgui.com> - 2021-07-28 21:09 +0000

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