Updated the cx16 library to the upstream project's prerelease 38.

libsrc/cx16/cputc.s

@@ -1,5 +1,5 @@
 ;
-; 2019-09-23, Greg King
+; 2020-10-13, Greg King
 ;
 ; void __fastcall__ cputcxy (unsigned char x, unsigned char y, char c);
 ; void __fastcall__ cputc (char c);
@@ -11,52 +11,47 @@
         .import         gotoxy, PLOT
 
         .include        "cx16.inc"
-        .macpack        generic
 
 
-; First, move to a new position.
+; Move to a cursor position, then print a character.
 
 _cputcxy:
         pha                     ; Save C
         jsr     gotoxy          ; Set cursor, drop x and y
-        pla                     ; Restore C
+        pla
 
-; Print a character.
+; Print a character -- also used as an internal function.
 
-_cputc: cmp     #$0D            ; LF?
+_cputc: cmp     #$0D            ; X16 '\n'?
         beq     newline
-        cmp     #$0A            ; CR?
-        beq     plotx0
+        cmp     #$0A            ; X16 '\r'?
+        beq     cr
 
-; Printable char of some sort
+; Printable char. of some sort.
+; Convert it from PetSCII into a screen-code.
 
-        cmp     #' '
-        blt     cputdirect      ; Other control char
+convert:
         tay
-        bmi     L10
-        cmp     #$60
-        blt     L2
-        and     #<~%00100000
-        bra     cputdirect
-
-; Handle character if high bit set
-
-L10:    and     #<~%10000000    ; Remove high bit
-        ora     #%01000000
-        bra     cputdirect
-
-L2:     and     #<~%01000000
+        lsr     a               ; Divide by 256/8
+        lsr     a
+        lsr     a
+        lsr     a
+        lsr     a
+        tax                     ; .X = %00000xxx
+        tya
+        eor     pet_to_screen,x
 
 cputdirect:
         jsr     putchar         ; Write character to screen, return .Y
 
-; Advance cursor position.
+; Advance the cursor position.
 
         iny
         cpy     LLEN            ; Reached end of line?
         bne     L3
-        jsr     newline         ; Next line
-        ldy     #$00            ; + CR
+        jsr     newline         ; Wrap around
+
+cr:     ldy     #$00
 L3:     sty     CURS_X
         rts
 
@@ -70,7 +65,6 @@ newline:
 
 ; Set the cursor's position, calculate RAM pointer.
 
-plotx0: stz     CURS_X
 plot:   ldy     CURS_X
         ldx     CURS_Y
         clc
@@ -96,3 +90,9 @@ putchar:
         lda     CHARCOLOR
         sta     VERA::DATA0
         rts
+
+
+        .rodata
+pet_to_screen:
+        .byte %10000000,%00000000,%01000000,%00100000  ; PetSCII -> screen-code
+        .byte %01000000,%11000000,%10000000,%10000000