mirror of https://github.com/cc65/cc65.git
72 lines
1.8 KiB
ArmAsm
72 lines
1.8 KiB
ArmAsm
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; Ullrich von Bassewitz, 06.08.1998
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; char cgetc (void);
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;
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.export _cgetc
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.constructor initcgetc
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.destructor donecgetc
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.import cursor
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.include "cbm_kernal.inc"
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.include "c128.inc"
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;--------------------------------------------------------------------------
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_cgetc: lda KEY_COUNT ; Get number of characters
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bne L2 ; Jump if there are already chars waiting
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; Switch on the cursor if needed. We MUST always switch the cursor on,
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; before switching it off, because switching it off will restore the
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; character attribute remembered when it was switched on. So just switching
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; it off will restore the wrong character attribute.
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jsr CURS_SET ; Set cursor to current position
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jsr CURS_ON
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lda cursor
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bne L1
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lda #$01
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jsr CURS_OFF
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L1: lda KEY_COUNT ; Check characters again
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beq L1
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jsr CURS_OFF ; Switch cursor off, if characters available
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L2: jsr KBDREAD ; Read char and return in A
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ldx #0
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rts
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;--------------------------------------------------------------------------
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; Module constructor/destructor
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.segment "INIT"
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keyvec: .res 2
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.segment "ONCE"
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initcgetc:
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; Save the old vector
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lda KeyStoreVec
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ldx KeyStoreVec+1
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sta keyvec
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stx keyvec+1
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; Set the new vector. I can only hope that this works for other C128
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; versions...
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lda #<$C6B7
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ldx #>$C6B7
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jmp SetVec
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.code
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donecgetc:
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lda keyvec
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ldx keyvec+1
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SetVec: sei
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sta KeyStoreVec
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stx KeyStoreVec+1
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cli
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rts
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