cc65/libsrc/c64/soft80_cgetc.s

;
; Groepaz/Hitmen, 11.10.2015
;
; high level implementation for the soft80 implementation
;
; char cgetc (void);
;

        .export         soft80_cgetc
        .import         soft80_internal_cellcolor, soft80_internal_cursorxlsb
        .import         cursor
        .importzp       tmp1

        .include        "cbm_kernal.inc"
        .include        "c64.inc"
        .include        "soft80.inc"

soft80_cgetc:
        lda     KEY_COUNT       ; Get number of characters
        bne     @L3             ; Jump if there are already chars waiting

        sec
        jsr     invertcursor    ; set cursor on or off accordingly

@L1:    lda     KEY_COUNT       ; wait for key
        beq     @L1

        clc
        jsr     invertcursor    ; set cursor on or off accordingly

@L3:    jsr     KBDREAD         ; Read char and return in A
        ldx     #0
        rts

; Switch the cursor on or off (invert)

invertcursor:
        lda     cursor
        bne     @invert
        rts
@invert:

        sei
        lda     $01             ; enable RAM under I/O
        pha
        lda     #$34
        sta     $01

        ; do not use soft80_putcolor here to make sure the cursor is always
        ; shown using the current textcolor without disturbing the "color voodoo"
        ; in soft80_cputc
        ldy     #0
        bcs     @set
        ; restore old value
        lda     tmp1
        bcc     @lp0
@set:
        ; save old value
        lda     (CRAM_PTR),y    ; vram
        sta     tmp1
        lda     soft80_internal_cellcolor
@lp0:
        sta     (CRAM_PTR),y    ; vram
        ldx     soft80_internal_cursorxlsb
        ldy     #7
@lp1:
        lda     (SCREEN_PTR),y
        eor     nibble,x
        sta     (SCREEN_PTR),y
        dey
        bpl     @lp1

        pla
        sta     $01             ; enable I/O
        cli
        rts

        .rodata
nibble: .byte $f0, $0f

;-------------------------------------------------------------------------------
; force the init constructor to be imported

        .import soft80_init
conio_init      = soft80_init
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00			`;`
move charset to seperate file again, added comments on charset layout 2015-10-11 15:13:28 +00:00			`; Groepaz/Hitmen, 11.10.2015`
			`;`
updated comments 2015-10-19 00:47:40 +00:00			`; high level implementation for the soft80 implementation`
			`;`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00			`; char cgetc (void);`
			`;`

			`.export soft80_cgetc`
use 'soft80_internal_cellcolor' for the current cell color, and CHARCOLOR for the actual textcolor 2015-10-14 15:24:16 +00:00			`.import soft80_internal_cellcolor, soft80_internal_cursorxlsb`
some cleanup, checked usage of __bgcolor and __textcolor 2015-09-28 14:10:11 +00:00			`.import cursor`
rewrote color voodoo 2015-10-09 21:39:37 +00:00			`.importzp tmp1`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00
Updated to use cbm_kernal.inc. Whitespace cleanups 2018-11-25 08:46:05 +00:00			`.include "cbm_kernal.inc"`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00			`.include "c64.inc"`
			`.include "soft80.inc"`

			`soft80_cgetc:`
			`lda KEY_COUNT ; Get number of characters`
style issues 2015-10-12 18:38:06 +00:00			`bne @L3 ; Jump if there are already chars waiting`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00
size optimization 2015-10-12 15:12:44 +00:00			`sec`
some more rework, second attempt on fixing the color issues. added ifdefs to disable the color voodoo alltogether for debugging purposes. 2015-10-08 18:43:25 +00:00			`jsr invertcursor ; set cursor on or off accordingly`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00
style issues 2015-10-12 18:38:06 +00:00			`@L1: lda KEY_COUNT ; wait for key`
			`beq @L1`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00
size optimization 2015-10-12 15:12:44 +00:00			`clc`
some more rework, second attempt on fixing the color issues. added ifdefs to disable the color voodoo alltogether for debugging purposes. 2015-10-08 18:43:25 +00:00			`jsr invertcursor ; set cursor on or off accordingly`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00
style issues 2015-10-12 18:38:06 +00:00			`@L3: jsr KBDREAD ; Read char and return in A`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00			`ldx #0`
			`rts`

some more rework, second attempt on fixing the color issues. added ifdefs to disable the color voodoo alltogether for debugging purposes. 2015-10-08 18:43:25 +00:00			`; Switch the cursor on or off (invert)`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00
some more rework, second attempt on fixing the color issues. added ifdefs to disable the color voodoo alltogether for debugging purposes. 2015-10-08 18:43:25 +00:00			`invertcursor:`
			`lda cursor`
			`bne @invert`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00			`rts`
some more rework, second attempt on fixing the color issues. added ifdefs to disable the color voodoo alltogether for debugging purposes. 2015-10-08 18:43:25 +00:00			`@invert:`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00
			`sei`
rewrote color voodoo 2015-10-09 21:39:37 +00:00			`lda $01 ; enable RAM under I/O`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00			`pha`
rewrote color voodoo 2015-10-09 21:39:37 +00:00			`lda #$34`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00			`sta $01`

Move comment block as requested 2020-07-15 20:44:34 +00:00			`; do not use soft80_putcolor here to make sure the cursor is always`
			`; shown using the current textcolor without disturbing the "color voodoo"`
			`; in soft80_cputc`
C64 soft80 conio: shave off a few bytes and cycles 2020-07-15 19:39:29 +00:00			`ldy #0`
			`bcs @set`
			`; restore old value`
			`lda tmp1`
			`bcc @lp0`
			`@set:`
			`; save old value`
			`lda (CRAM_PTR),y ; vram`
			`sta tmp1`
			`lda soft80_internal_cellcolor`
			`@lp0:`
			`sta (CRAM_PTR),y ; vram`
maintain lsb of cursor x position internally, saves some bytes and some cycles too :) 2015-10-12 13:44:41 +00:00			`ldx soft80_internal_cursorxlsb`
C64 soft80-conio cgetc: save 14 cycles in `invertcursor` By 'inverting' the loop, we can save 16 cycles by removing the `cpy #8`, saving 16 cycles. But we need an extra `ldy #7` at the start of the loop, so the total cycles saved is 14. Code size doesn't increase due to the addition of the `ldy #7` negating the removal of the `cpy #xx`. 2020-07-11 11:18:14 +00:00			`ldy #7`
some more rework, second attempt on fixing the color issues. added ifdefs to disable the color voodoo alltogether for debugging purposes. 2015-10-08 18:43:25 +00:00			`@lp1:`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00			`lda (SCREEN_PTR),y`
some more rework, second attempt on fixing the color issues. added ifdefs to disable the color voodoo alltogether for debugging purposes. 2015-10-08 18:43:25 +00:00			`eor nibble,x`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00			`sta (SCREEN_PTR),y`
C64 soft80-conio cgetc: save 14 cycles in `invertcursor` By 'inverting' the loop, we can save 16 cycles by removing the `cpy #8`, saving 16 cycles. But we need an extra `ldy #7` at the start of the loop, so the total cycles saved is 14. Code size doesn't increase due to the addition of the `ldy #7` negating the removal of the `cpy #xx`. 2020-07-11 11:18:14 +00:00			`dey`
			`bpl @lp1`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00
			`pla`
size optimization 2015-10-12 15:12:44 +00:00			`sta $01 ; enable I/O`
initial commit of soft80 implementation 2015-09-27 16:12:25 +00:00			`cli`
			`rts`

some more rework, second attempt on fixing the color issues. added ifdefs to disable the color voodoo alltogether for debugging purposes. 2015-10-08 18:43:25 +00:00			`.rodata`
			`nibble: .byte $f0, $0f`
some cleanup/rework 2015-10-09 11:34:23 +00:00
			`;-------------------------------------------------------------------------------`
			`; force the init constructor to be imported`

			`.import soft80_init`
			`conio_init = soft80_init`