Checkpoint of my Swing UI refactoring. Usable for output-only programs, but only barely.

samples/hello.asm

@@ -3,18 +3,30 @@
 ;;
 
 
-.alias cr  $0d
-.alias lf  $0a
-
-.alias out $c000
+.alias iobase   $c000
+.alias iostatus [iobase + 1]
+.alias iocmd    [iobase + 2]
+.alias ioctrl   [iobase + 3]
 
 .org $0300
 
-start:  ldx #$00
+start:  cli
+        lda #$09
+        sta iocmd      ; Set command status
+        lda #$16
+        sta ioctrl     ; 0 stop bits, 8 bit word, 300 baud
+        ldx #$00       ; Initialize index
+
 loop:   lda string,x
         beq start      ; If A is 0, loop back and start again
-        sta out        ; Otherwise, store into output
-        inx            ; Increment X
+
+write:  lda iostatus
+        and #$10       ; Load ACIA status. Is output buffer empty?
+        beq write      ; If not, loop back and try again,
+        lda string,x
+        sta iobase     ; Otherwise, write to output.
+
+        inx
         jmp loop       ; Repeat.
 
 string: .byte "Hello, 6502 world! ", 0