Synertek Systems Sym-1 machine-specific files

2021-05-09 16:34:53 -05:00
parent 07bd5089ec
commit 6e79379405
23 changed files with 2088 additions and 0 deletions
--- a/libsrc/sym1/read.s
+++ b/libsrc/sym1/read.s
@@ -0,0 +1,54 @@
+; ---------------------------------------------------------------------------
+; read.s
+;
+; for Sym-1
+;
+; Wayne Parham
+;
+; wayne@parhamdata.com
+; ---------------------------------------------------------------------------
+
+.include        "sym1.inc"
+
+.import         popax, popptr1
+.importzp       ptr1, ptr2, ptr3
+
+.export         _read
+
+.proc           _read
+; ---------------------------------------------------------------------------
+        sta     ptr3
+        stx     ptr3+1           ; Count in ptr3
+        inx
+        stx     ptr2+1           ; Increment and store in ptr2
+        tax
+        inx
+        stx     ptr2
+        jsr     popptr1          ; Buffer address in ptr1
+        jsr     popax
+
+begin:  dec     ptr2
+        bne     getch
+        dec     ptr2+1
+        beq     done             ; If buffer full, return
+
+getch:  jsr     INTCHR           ; Get character using Monitor ROM call
+        jsr     OUTCHR           ; Echo it
+        and     #$7F             ; Clear hi bit and check for '\r'
+        cmp     #$0D
+        bne     putch
+        lda     #$0A             ; Replace with '\n' and set count to zero
+
+putch:  ldy     #$00             ; Put char into return buffer
+        sta     (ptr1),y
+        inc     ptr1             ; Increment pointer
+        bne     begin
+        inc     ptr1+1
+        bne     begin
+
+done:   lda     ptr3
+        ldx     ptr3+1
+        rts                      ; Return count                       
+; ---------------------------------------------------------------------------
+.endproc
+