Comments for page "Appvars" http://z80-heaven.wikidot.com/forum/t-98069/appvars Posts in the discussion thread "Appvars" Fri, 13 Mar 2026 07:22:30 +0000 http://z80-heaven.wikidot.com/forum/t-98069#post-1729656 Appvars http://z80-heaven.wikidot.com/forum/t-98069/appvars#post-1729656 Tue, 12 Mar 2013 19:36:30 +0000 Xeda Elnara 595803

In the last tutorial we pointed out that you can not create permanent self modifying code.

This is bugging me because you definitely can do this. The OS leaves the name of the executing program in OP1, so you can do something like:

 bcall(_ChkFindSym) ld hl,smc_num-9D95h+4 ;+4 because DE points tot he size bytes and 2 bytes are the header BB6Dh add hl,de ld e,(hl) inc hl ld d,(hl) inc de ld (hl),d dec hl ld (hl),e ex de,hl bcall(_DispHL) ret smc_num: .dw 0

Note that this won't work on the uncompressed hex codes, so you need to either make sure to use AsmComp() or have it compiled by some compiler. ]]>