remove superfluous ".code" line

[cc65] / libsrc / cbm510 / cgetc.s

diff --git a/libsrc/cbm510/cgetc.s b/libsrc/cbm510/cgetc.s
index 971d66db2a5dbaabdcc24f5278cf85eaf6d45626..5fed54e0a52592d82f29350ca4680803d96287e4 100644 (file)
--- a/libsrc/cbm510/cgetc.s
+++ b/libsrc/cbm510/cgetc.s
@@ -1,38 +1,152 @@
 ;
-; Ullrich von Bassewitz, 06.08.1998
+; Ullrich von Bassewitz, 16.09.2001
 ;
 ; char cgetc (void);
 ;
 
        .export         _cgetc
-       .import         plot, write_crtc
+       .condes         k_blncur, 2
        .import         cursor
 
-       .include        "zeropage.inc"
-       .include        "page3.inc"
+       .include        "cbm510.inc"
+        .include        "extzp.inc"
 
 
 ; ------------------------------------------------------------------------
 
 .proc  _cgetc
 
-L1:            lda     KeyIndex
-               beq     L1
+       lda     keyidx                  ; Characters waiting?
+               bne     L3                      ; Jump if so
 
-L2:            ldx     #$00            ; Get index
-               ldy     KeyBuf          ; Get first character in the buffer
+; Switch on the cursor if needed
+
+       lda     CURS_FLAG
+       pha
+       lda     cursor
+       jsr     setcursor
+L1:    lda     keyidx
+       beq     L1
+       ldx     #0
+       pla
+       bne     L2
+               inx
+L2:            txa
+               jsr     setcursor
+
+; Read the character from the keyboard buffer
+
+L3:            ldx     #$00            ; Get index
+               ldy     keybuf          ; Get first character in the buffer
                sei
-L3:            lda     KeyBuf+1,x      ; Move up the remaining chars
-               sta     KeyBuf,x
+L4:            lda     keybuf+1,x      ; Move up the remaining chars
+               sta     keybuf,x
                inx
-               cpx     KeyIndex
-               bne     L3
-               dec     KeyIndex
+               cpx     keyidx
+               bne     L4
+               dec     keyidx
                cli
 
-               ldx     #$00            ; High byte
-               tya                     ; First char from buffer
+               ldx     #$00            ; High byte
+               tya                     ; First char from buffer
                rts
 
 .endproc
 
+; ------------------------------------------------------------------------
+;
+
+.proc  setcursor
+
+       ldy     #$00                    ;
+               tax                             ; On or off?
+               bne     @L9                     ; Go set it on
+       lda     CURS_FLAG               ; Is the cursor currently off?
+               bne     @L8                     ; Jump if yes
+       lda     #1
+       sta     CURS_FLAG               ; Mark it as off
+       lda     CURS_STATE              ; Cursor currently displayed?
+       sty     CURS_STATE              ; Cursor will be cleared later
+               beq     @L8                     ; Jump if no
+
+; Switch to the system bank, load Y with the cursor X coordinate
+
+       lda     #$0F
+       sta     IndReg                  ; Access system bank
+       ldy     CURS_X
+
+; Reset the current cursor
+
+       lda     CURS_COLOR
+       sta     (CRAM_PTR),y            ; Store cursor color
+       lda     ExecReg
+       sta     IndReg                  ; Switch to our segment
+       lda     (SCREEN_PTR),y
+       eor     #$80                    ; Toggle reverse flag
+       sta     (SCREEN_PTR),y
+
+; Done
+
+@L8:   rts
+
+@L9:   sty     CURS_FLAG               ; Cursor on (Y = 0)
+       rts
+
+.endproc
+
+
+; ------------------------------------------------------------------------
+; Blink the cursor in the interrupt. A blinking cursor is only available if
+; we use the cgetc() function, so we will export this IRQ handler only in
+; case the module is included into a program.
+
+
+.proc   k_blncur
+
+        lda     CURS_FLAG              ; Is the cursor on?
+        bne     curend                 ; Jump if not
+        dec     CURS_BLINK
+        bne     curend
+
+; Re-initialize the blink counter
+
+        lda     #20                    ; Initial value
+        sta     CURS_BLINK
+
+; Load Y with the cursor X coordinate
+
+       ldy     CURS_X
+
+; Check if the cursor state was on or off before
+
+       lda     CURS_COLOR              ; Load color behind cursor
+       lsr     CURS_STATE              ; Cursor currently displayed?
+       bcs     curset                  ; Jump if yes
+
+; Cursor was off before, switch it on
+
+       inc     CURS_STATE              ; Mark as displayed
+       lda     (CRAM_PTR),y            ; Get color behind cursor...
+       sta     CURS_COLOR              ; ...and remember it
+       lda     CHARCOLOR               ; Use character color
+
+; Set the cursor with color in A
+
+curset:        sta     (CRAM_PTR),y            ; Store cursor color
+       lda     ExecReg
+       sta     IndReg                  ; Switch to our segment
+       lda     (SCREEN_PTR),y
+       eor     #$80                    ; Toggle reverse flag
+       sta     (SCREEN_PTR),y
+
+; Switch back to the system bank
+
+       lda     #$0F
+       sta     IndReg
+
+curend:        rts
+
+.endproc
+
+
+