Pass print "color" in ZP variable instead of the stack.

This makes the code smaller.

Author: dmsc

src/interp/atari/print_tab.asm

@@ -28,7 +28,7 @@
 ; ---------------------------------------------
 
         .import         putc, stack_l, print_str_tmp1
-        .importzp       sptr, next_instruction, tmp1, tmp2
+        .importzp       sptr, next_instruction, tmp1, tmp2, PRINT_ARG
 
         .include "target.inc"
 
@@ -72,6 +72,7 @@ ok:
 
         inc     sptr
         ldy     #0              ; Print color = 0
+        sty     PRINT_ARG
         jmp     print_str_tmp1  ; Print string in tmp1
 .endproc
 

src/interp/print_str.asm

@@ -29,31 +29,27 @@
 
         .import         putc, stack_l
         .importzp       tmp1, tmp2, tmp3, next_instruction, sptr
+        .exportzp       PRINT_ARG
         .export         print_str_tmp1
 
+PRINT_ARG = tmp3
+
         .segment        "RUNTIME"
 
-.proc   EXE_PRINT_COLOR_STR   ; PRINT string in AX
-        pha
-        lda     stack_l, y
-        inc     sptr
-        tay
-        pla
-        .byte   $2C     ; Skip 2 bytes over next "LDY"
-.endproc
-.proc   EXE_PRINT_STR   ; PRINT string in AX
+.proc   EXE_PRINT_STR   ; PRINT string in AX, with color 0
         ldy     #0
+        sty     PRINT_ARG
+::EXE_PRINT_COLOR_STR:  ; PRINT string in AX with given color
         sta     tmp1
         stx     tmp1+1
 ptmp:                   ; Prints string in TMP1
-        sty     tmp3
         ldy     #0
         lda     (tmp1), y       ; LENGTH
         beq     nil
         sta     tmp2
 loop:   iny
         lda     (tmp1), y
-        eor     tmp3
+        eor     PRINT_ARG
         jsr     putc
         cpy     tmp2
         bne     loop

src/parse.asm

@@ -36,7 +36,7 @@
         ; From vars.asm
         .exportzp       var_count, label_count
         ; From runtime.asm
-        .importzp       IOCHN, COLOR, IOERROR
+        .importzp       IOCHN, COLOR, IOERROR, PRINT_ARG
         .import         putc
         ; From interpreter.asm
         .importzp       DEGFLAG, DEGFLAG_DEG, DEGFLAG_RAD, saved_cpu_stack

src/syntax/basic.syn

@@ -98,6 +98,7 @@ SYMBOLS {
 
  BASIC_TOP = importzp
  IOERROR = importzp
+ PRINT_ARG = importzp
  MEMTOP = import
  CLEAR_DATA = import
  ATEOL = 155
@@ -297,7 +298,7 @@ PRINT_SEP_EOL:
 
 # - One item to print, converted to string:
 PRINT_ONE_STR:
-        "Color" T_EXPR emit { TOK_PUSH } PRINT_ONE emit TOK_PRINT_COLOR_STR
+        "Color" T_EXPR emit { TOK_BYTE_POKE, PRINT_ARG } PRINT_ONE emit TOK_PRINT_COLOR_STR
         PRINT_ONE emit TOK_PRINT_STR
         pass