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cc65/libsrc/c128/cgetc.s
uz 2bd1f2f69f Fixed a problem with a disabled cursor: Switching off the cursor using the
kernal routine does not work, when the cursor is not at the same position
where it was switched on, because when switching it on, the kernal remembers
the character attribute and restores this when switching it off. So characters
may get the wrong attribute. The solution is to always switch the cursor on,
before switching it off.


git-svn-id: svn://svn.cc65.org/cc65/trunk@4592 b7a2c559-68d2-44c3-8de9-860c34a00d81
2010-02-18 20:31:50 +00:00

73 lines
1.5 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. We MUST always switch the cursor on,
; before switching it off, because switching it off will restore the
; character attribute remembered when it was switched on. So just switching
; it off will restore the wrong character attribute.
jsr CURS_SET ; Set cursor to current position
jsr CURS_ON
lda cursor
bne L1
lda #$01
jsr CURS_OFF
L1: lda KEY_COUNT ; Check characters again
beq L1
jsr CURS_OFF ; Switch cursor off, if characters available
L2: jsr KBDREAD ; Read char and return in A
ldx #0
rts
;--------------------------------------------------------------------------
; Module constructor/destructor
.bss
keyvec: .res 2
.segment "INIT"
initcgetc:
; Save the old vector
lda KeyStoreVec
sta keyvec
lda KeyStoreVec+1
sta keyvec+1
; Set the new vector. I can only hope that this works for other C128
; versions...
lda #<$C6B7
ldx #>$C6B7
jmp SetVec
.code
donecgetc:
lda keyvec
ldx keyvec+1
SetVec: sei
sta KeyStoreVec
stx KeyStoreVec+1
cli
rts