Programming:Storing and Retrieving Screens from the extra 64kb
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Revision as of 03:32, 11 August 2018 by CPM User (Talk | contribs) (Created page with "== Overview == This routine comes from the Push-Pop program which was published in Issue 57 of Amstrad Action, however while that progra...")
Overview
This routine comes from the Push-Pop program which was published in Issue 57 of Amstrad Action, however while that program is useful for Storing and Retrieving Screens in the 6128s extra 64k, it's only going to work on the 6128, so other computers with memory expansions won't be able to use it, this updated routine will work on all systems (as long as they have 128kb minimum).
The Program
org &a500 ld bc,table ld hl,workspace call &bcd1 ret .workspace defb 0,0,0,0 .table defw table2 jp push jp pop .table2 defb "PUS" defb "H"+&80 defb "PO" defb "P"+&80 defb 0 .push cp &01 ret nz ld a,(ix+&00) cp &05 ret nc add &c3 ld c,a ld b,&7f out (c),c ld de,&4000 ld hl,&c000 ld bc,&3fff ldir ld bc,&7fc0 out (c),c ret .pop cp &01 ret nz ld a,(ix+&00) cp &05 ret nc add &c3 ld c,a ld b,&7f out (c),c ld de,&c000 ld hl,&4000 ld bc,&3fff ldir ld bc,&7fc0 out (c),c ret defb 0
