Optimized the code a bit as suggested by Greg.

[cc65] / libsrc / c128 / cputc.s

diff --git a/libsrc/c128/cputc.s b/libsrc/c128/cputc.s
index c3b835e13a19b04869a7a69cdf77eac196f30f40..9d269a47e1169d16cecb800aa8f32741ae55ad33 100644 (file)
--- a/libsrc/c128/cputc.s
+++ b/libsrc/c128/cputc.s
@@ -1,43 +1,88 @@
 ;
-; Ullrich von Bassewitz, 06.08.1998
+; Ullrich von Bassewitz, 2000-08-06, 2002-12-21
+; Using lots of code from MagerValp, MagerValp@cling.gu.se
 ;
 ; void cputcxy (unsigned char x, unsigned char y, char c);
 ; void cputc (char c);
 ;
 
-       .export         _cputcxy, _cputc, cputdirect, putchar
-       .export         newline, plot
-       .import         popa, _gotoxy
+        .export         _cputcxy, _cputc, cputdirect, putchar
+        .export         newline, plot
+        .import         gotoxy
         .import         PLOT
 
-       .include        "c128.inc"
+        .include        "c128.inc"
 
+newline         = NEWLINE
+
+;--------------------------------------------------------------------------
+
+.code
 
 _cputcxy:
-       pha                     ; Save C
-       jsr     popa            ; Get Y
-       jsr     _gotoxy         ; Set cursor, drop x
-       pla                     ; Restore C
-       jmp     PRINT
+        pha                     ; Save C
+        jsr      gotoxy         ; Set cursor, drop x and y
+        pla                     ; Restore C
 
 ; Plot a character - also used as internal function
 
-_cputc         = PRINT         ; let the kernal handle it
+_cputc: cmp     #$0A            ; CR?
+        beq     cr              ; Output a cr
+
+        cmp     #$0D            ; LF?
+        bne     L2
+        jmp     NEWLINE         ; Update cursor position
+
+; Printable char of some sort
+
+L2:     cmp     #' '
+        bcc     cputdirect      ; Other control char
+        tay
+        bmi     L5
+        cmp     #$60
+        bcc     L3
+        and     #$DF
+        bne     cputdirect      ; Branch always
+L3:     and     #$3F
 
-cputdirect     = $c33b
+; Output one character to the screen. We will disable scrolling while doing so
 
-newline:
-       lda     #17
-       jmp     PRINT
+cputdirect:
+        tax                     ; Save output char
+        lda     SCROLL
+        pha                     ; Save scroll flag
+        lda     #$C0
+        sta     SCROLL          ; Disable scrolling
+        txa                     ; Restore output char
+        jsr     PRINT
+        pla
+        sta     SCROLL          ; Restore old scroll flag
+        rts
+
+; Handle character if high bit set
+
+L5:     and     #$7F
+        cmp     #$7E            ; PI?
+        bne     L6
+        lda     #$5E            ; Load screen code for PI
+        bne     cputdirect
+L6:     ora     #$40
+        bne     cputdirect      ; Branch always
+
+; Carriage return
+
+cr:     lda     #0
+        sta     CURS_X
 
 ; Set cursor position, calculate RAM pointers
 
-plot:  ldy     CURS_X
-       ldx     CURS_Y
-       clc
-       jmp     PLOT            ; Set the new cursor
+plot:   ldy     CURS_X
+        ldx     CURS_Y
+        clc
+        jmp     PLOT            ; Set the new cursor
 
 ; Write one character to the screen without doing anything else, return X
 ; position in Y
 
-putchar        = $CC2F
+putchar = $CC2F
+