Start on FILE i/O

rom/extra.s

@@ -1,34 +1,126 @@
 .segment "EXTRA"
 
-LOAD:
+; IO
+
+CHKIN:
+        stx CURDVC
+        stx IO_FILE_DESCRIPTOR
+        lda IO_COMMAND_SELECT_IN
+        sta IO_FILE_COMMAND
         rts
 
-SAVE:
+CHKOUT:
+        stx CURDVC
+        stx IO_FILE_DESCRIPTOR
+        lda IO_COMMAND_SELECT_OUT
+        sta IO_FILE_COMMAND
         rts
 
+CLRCH:
+        lda #0
+        sta CURDVC
+        lda IO_COMMAND_RESET
+        sta IO_FILE_COMMAND
+        rts
+
+CHRIN:
+        lda CURDVC
+        bne @file
+        lda IO_KBD
+        bmi @end
+        jsr CHROUT ; echo
+@file:
+        lda IO_COMMAND_READ
+        sta IO_FILE_COMMAND
+@wait:
+        lda IO_FILE_STATUS
+        and #FILE_STATUS_READY
+        beq @wait
+        lda IO_FILE_DATA
+@end:
+        rts
+
+CHROUT:
+        lda CURDVC
+        bne @file
+        sta IO_SCREEN
+        rts
+@file:
+        sta IO_FILE_DATA
+        lda IO_COMMAND_WRITE
+        sta IO_FILE_COMMAND
+@wait:
+        lda IO_FILE_STATUS
+        and #$4
+        beq @wait
+        rts
+
+OPEN:
+        jsr GETBYT
+        stx IO_FILE_DESCRIPTOR
+        jsr CHKCOM
+        jsr FRMEVL
+        jsr CHKSTR
+        jsr FREFAC
+        sta STRNG2
+        ldy #0
+@copy:
+        cpy STRNG2
+        beq @done_copy
+        lda (INDEX),y
+        sta FILE_NAME_BUFFER,y
+        iny
+        bne @copy
+@done_copy:
+        lda #0
+        sta FILE_NAME_BUFFER,y
+        lda #<FILE_NAME_BUFFER
+        sta IO_FILE_DATA
+        lda #>FILE_NAME_BUFFER
+        sta IO_FILE_DATA+1
+        lda #IO_COMMAND_OPEN
+        sta IO_FILE_COMMAND
+@wait:
+        lda IO_FILE_STATUS
+        and #FILE_STATUS_READY
+        beq @wait
+        lda #FILE_STATUS_READY
+        and #$01
+        bne @error
+        rts
+@error:
+        jmp     IQERR
+
+CLOSE:
+        rts
+
+; Default
+
 ISCNTC:
-        lda $BC01
+        lda IO_KBD
         cmp #$03
         beq :+
         rts
 :
         jmp STOP
 
-MONRDKEY:
-        lda $BC01
-        bmi :+
-        sta $BC00       ; echo
-:
+SYS:
+        jsr GTNUM
+        lda LINNUM
+        sta SYSJMP+1
+        lda LINNUM+1
+        sta SYSJMP+2
+SYSJMP:
+        jsr $FFFF
         rts
 
-MONCOUT:
-        sta $BC00
-        rts
+MONRDKEY := CHRIN
+MONCOUT  := CHROUT
 
 .segment "WOZMON"
 .include "wozmon.s"
 
 .segment "RESETVEC"
-        .word   $0000           ; NMI vector
-        .word   COLD_START      ; RESET vector
-        .word   $0000           ; IRQ vector
+.word   $0000           ; NMI vector
+.word   COLD_START      ; RESET vector
+.word   $0000           ; IRQ vector