Merge pull request #175 from davidgiven/ccp

Fix some user number handling.

lib/xfcb.S

@@ -3,6 +3,7 @@
 
 ZEROPAGE
 __fcb: .fill 2
+__olduser: .fill 1
 
 ; Preserves XA.
 zproc xfcb_clear
@@ -26,45 +27,67 @@ zendproc
 zproc xfcb_prepare
     sta __fcb+0
     stx __fcb+1
+    lda #0xff
+    jsr xfcb_getsetuser
+    sta __olduser
     ldy #XFCB_US
     lda (__fcb), y
-    ldy #BDOS_GET_SET_USER_NUMBER
-    jsr BDOS
+    jsr xfcb_getsetuser
     lda __fcb+0
     ldx __fcb+1
     rts
 zendproc
 
+zproc xfcb_execute
+    jsr BDOS
+    php
+    pha
+    txa
+    pha
+    lda __olduser
+    jsr xfcb_getsetuser
+    pla
+    tax
+    pla
+    plp
+    rts
+zendproc
+
+zproc xfcb_getsetuser
+    ldy #BDOS_GET_SET_USER_NUMBER
+    jmp BDOS
+zendproc
+
 zproc xfcb_open
     jsr xfcb_prepare
     jsr xfcb_clear
     ldy #BDOS_OPEN_FILE
-    jmp BDOS
+    jmp xfcb_execute
 zendproc
 
 zproc xfcb_close
     jsr xfcb_prepare
     ldy #BDOS_CLOSE_FILE
-    jmp BDOS
+    jmp xfcb_execute
 zendproc
 
 zproc xfcb_erase
     jsr xfcb_prepare
     jsr xfcb_clear
     ldy #BDOS_DELETE_FILE
-    jmp BDOS
+    jmp xfcb_execute
 zendproc
 
 zproc xfcb_readsequential
     jsr xfcb_prepare
     ldy #BDOS_READ_SEQUENTIAL
-    jmp BDOS
+    jmp xfcb_execute
 zendproc
 
 zproc xfcb_writesequential
     jsr xfcb_prepare
     ldy #BDOS_WRITE_SEQUENTIAL
-    jmp BDOS
+    jmp xfcb_execute
 zendproc
 
 ; vim: sw=4 ts=4 et ft=asm

src/bdos/exit.S

@@ -20,6 +20,13 @@ zproc bdos_EXIT
     jsr bios_NEWLINE
     jsr bdos_RESET
 
+    ; The CCP.SYS is always loaded from user 0; switch users (but save the old one).
+
+    lda current_user
+    pha
+    lda #0
+    sta current_user
+
     ; Open the CCP.SYS file.
 
     lda #0
@@ -125,7 +132,12 @@ zproc bdos_EXIT
     lda temp+1              ; start of TPA, in pages
     jsr bios_RELOCATE
 
-    ; Execute it.
+    ; Restore the old user.
+
+    pla
+    sta current_user
+
+    ; Execute the CCP.
 
     lda #BANK_MAIN
     jsr bios_SETBANK