Serial: Optimize TryToSend

We don't need to reload SendFreeCnt each time we loop to wait for the ACIA to be ready.
2023-08-30 21:28:09 +02:00
parent c674b7ced4
commit 3f3b6123b9
7 changed files with 43 additions and 41 deletions
--- a/libsrc/apple2/ser/a2.ssc.s
+++ b/libsrc/apple2/ser/a2.ssc.s
@@ -427,12 +427,13 @@ Done:   rts

 TryToSend:
        sta     tmp1            ; Remember tryHard flag
-Again:  lda     SendFreeCnt
+NextByte:
+        lda     SendFreeCnt
        cmp     #$FF
        beq     Quit            ; Bail out

        ; Check for flow stopped
-        lda     Stopped
+Again:  lda     Stopped
        bne     Quit            ; Bail out

        ; Check that ACIA is ready to send
@@ -449,4 +450,4 @@ Send:   ldy     SendHead
        sta     ACIA_DATA,x
        inc     SendHead
        inc     SendFreeCnt
-        jmp     Again
+        jmp     NextByte