84PCE:OS:VAT
From WikiTI
Revision as of 11:09, 26 May 2015 by MateoConLechuga (Talk | contribs)
The VAT has remained pretty much the same, as has the structure of archived variables.
One important thing to note is that the ROM page offset is now a part of the whole address, which is nice in order to maintain backwards compatibility.
Traversing the VAT Example:
;-------------------------------------------- ; fdetect ; detects appvars, prot progs, and ; progs given a 0-terminated string ; pointed to by ix. ;-------------------------------------------- ; INPUTS: ; hl->place to start searching ; ix->string to find ; ; OUTPUTS: ; hl->place stopped searching ; de->file data after string ; bc=file size after string ; z flag set if found, nz if not found ;-------------------------------------------- fdetect: ld de,(ptemp) or a,a sbc hl,de add hl,de ld a,(hl) jr nz,fcontinue inc a ret fcontinue: push hl cp appvarobj jr z,fgoodtype cp protprogobj jr z,fgoodtype cp progobj jr nz,fskip fgoodtype: dec hl dec hl dec hl ld e, (hl) dec hl ld d,(hl) dec hl ld a,(hl) call _SetDEUtoA push de pop hl cp 0D0h jr nc,finRAM push ix push de push hl pop ix ld a,10 add a,(ix+9) ld de,0 ld e,a add hl,de ex (sp),hl add hl,de pop de ex de,hl pop ix finRAM: inc de inc de ld bc,0 ld c,(hl) inc hl ld b,(hl) inc hl ; hl -> data push bc ; bc = size push ix pop bc fchkstr: ld a,(bc) or a jr z,ffound cp (hl) inc bc inc de inc hl jr z,fchkstr pop bc fskip: pop hl call fbypassname jr fdetect ffound: push bc pop hl push ix pop bc or a sbc hl,bc push hl pop bc pop hl ; size or a sbc hl,bc push hl pop bc pop hl ; current search location push bc call fbypassname pop bc xor a ret fbypassname: ld bc,-6 add hl,bc ld b,(hl) dec hl fbypassnameloop: dec hl djnz fbypassnameloop ret