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  • list running prog c64 basic v2

    From Grant Weasner@1:138/397 to All on Monday, February 09, 2026 15:16:51
    Hello all,

    I've been trying to construct a cool program as a visual like a screen saver in basic. I'm not very good at basic, but I'm having fun with it.

    I was going for something that kinda looks like a display in movies like bladerunner, or outland. Those older late 80's sci-fi films.

    I thought a listing of a running basic program would be a cool part to GOTO with a maze type program.

    I wanted to get your thoughts on the way I listed a running program. My code snip doesn't include my entire program but I attached this snip to the end of my maze program to try and create a need look.


    5 print "initializing...": dim k$(255): rp=41111
    6 for t=124 to 255: w$="": rem --- fill the cache ---
    7 b=peek(rp): w$=w$+chr$(b and 127): rp=rp+1
    8 if b<128 goto 7
    9 k$(t)=w$+" ": if rp < 41581 then next t
    10 ad = 2049: print chr$(147)
    20 nx = peek(ad) + 256 * peek(ad+1)
    30 if nx = 0 then end
    40 ln = peek(ad+2) + 256 * peek(ad+3)
    50 print ln; " ";
    60 for i = ad + 4 to nx - 2
    70 c = peek(i): if c < 128 then print chr$(c);: goto 100
    80 print k$(c);
    100 next i: print: ad = nx: goto 20



    The array is initialized with the rom key words to list the program running program.
    If I had just put:

    10 list
    20 goto 10

    it wouldn't work because list executes something like a run-stop first.

    try it out.
    --- SBBSecho 3.20-Linux
    * Origin: Lunar Outpost - lunarout.synchro.net (1:138/397)
  • From Tilmann Hentze@3:633/10 to All on Tuesday, February 10, 2026 21:00:02
    Grant Weasner <usenet@vk3heg.net> schrieb:
    If I had just put:
    10 list
    20 goto 10
    it wouldn't work because list executes something like a run-stop first.

    This works silmilarily as your program for me: The programm lists itself and
    then stops. I wonder why.
    I tested this with vice and yapesdl.

    I'll try to comment your program:

    Lines 5 to 9 copies the BASIC keywords to k$() array.
    5 print "initializing...": dim k$(255): rp=41111
    6 for t=124 to 255: w$="": rem --- fill the cache ---
    7 b=peek(rp): w$=w$+chr$(b and 127): rp=rp+1
    8 if b<128 goto 7
    9 k$(t)=w$+" ": if rp < 41581 then next t

    The BASIC program starts at 2049, this is the addres of the first line;
    clear the screen
    10 ad = 2049: print chr$(147)

    The next BASIC line number is at this address
    20 nx = peek(ad) + 256 * peek(ad+1)

    This is the end of the program
    30 if nx = 0 then end

    Get the BASIC program line number and print it
    40 ln = peek(ad+2) + 256 * peek(ad+3)
    50 print ln; " ";

    Loop from line's start of text to end of line
    60 for i = ad + 4 to nx - 2

    Get a byte. If its value less than 128 then it is a character, print it
    70 c = peek(i): if c < 128 then print chr$(c);: goto 100

    It is a BASIC token, lookup in keywords table and print it.
    80 print k$(c);

    Loop end; print an empty line; next BASIC line address; restart loop
    100 next i: print: ad = nx: goto 20

    Best regards,
    Tilmann.
    --
    Wo sich noch Bit und Byte gute Nacht sagen.

    --- PyGate Linux v1.5.11
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)