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cc65/libsrc/c128/cgetc.s
cuz ea4d2f4e6f Fixed several problems with the new output routines
git-svn-id: svn://svn.cc65.org/cc65/trunk@1823 b7a2c559-68d2-44c3-8de9-860c34a00d81
2002-12-21 14:11:32 +00:00

72 lines
1.2 KiB
ArmAsm

;
; Ullrich von Bassewitz, 06.08.1998
;
; char cgetc (void);
;
.export _cgetc
.constructor initcgetc
.destructor donecgetc
.import cursor
.include "c128.inc"
;--------------------------------------------------------------------------
_cgetc: lda KEY_COUNT ; Get number of characters
bne L2 ; Jump if there are already chars waiting
; Switch on the cursor if needed
lda cursor
beq L1
jsr CURS_SET ; Set cursor to current position
jsr CURS_ON
jmp L2
L1: lda #$01
jsr CURS_OFF
L2: lda KEY_COUNT ; Check characters again
beq L2
jsr CURS_OFF ; Switch cursor off, if characters available
jsr KBDREAD ; Read char and return in A
ldx #0
rts
;--------------------------------------------------------------------------
; Module constructor/destructor
.bss
keyvec: .res 2
.code
initcgetc:
; Save the old vector
lda KeyStoreVec
sta keyvec
lda KeyStoreVec+1
sta keyvec+1
; Set the new vector. I can only hope that this works for other C128
; versions...
lda #<$C6B7
ldx #>$C6B7
SetVec: sei
sta KeyStoreVec
stx KeyStoreVec+1
cli
rts
donecgetc:
lda #$00
sta SCROLL
lda keyvec
ldx keyvec+1
bne SetVec