Apple-2-SW/apple2_hgrbyte
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Add note about zpage E0,E1,E2 HPOSN

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Michaelangel007 2017-10-30 08:14:48 -07:00
parent 85f890a30e
commit 335fbc1a68
1 changed files with 5 additions and 3 deletions
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8
src/dhgr.byte.s
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@ -720,7 +720,7 @@ OnLoadSprite
LoadRows
; Y -> Source Address
LDA gSpriteY
JSR GetHgrBaseAddr
JSR GetHgrBaseAddr ; cursor_row is updated -> HPOSN
LDA cursor_col
STA gSpriteX
@ -1129,6 +1129,8 @@ FlipBit
; IN:
; A=Y
; OUT:
; $E0,E1 = 0..279 x (column)
; $E2 = y (row)
; $26,27 = HGR1 addr
; $F7,F8 = HGR2 addr
GetHgrBaseAddr
@ -1141,8 +1143,8 @@ GetHgrBaseAddr
LDA GBASL
STA aux_ptr+0
LDA GBASH
AND #$1F
ORA #$40
AND #$1F ; stripe page 1
ORA #$40 ; set to page 2
STA aux_ptr+1
FIN
RTS