passport/src/slots.a

DiskIIArray
         !byte 00,00,00,00,00,00,00

;-------------------------------
; ScanForDiskII
; scan all slots for things that
; look like Disk II cards
;
; out: all registers clobbered
;      all flags clobbered
;      DiskIIArray filled with 00 or FF
;-------------------------------
!zone {
ScanForDiskII
         lda   #$00
         sta   cmp1
         ldx   #$07
.fingerprint
         txa
         ora   #$C0
         sta   cmp1+1
         ldy   #$01
         lda   (cmp1),y
         cmp   #$20
         bne   .next
         ldy   #$03
         lda   (cmp1),y
         bne   .next
         ldy   #$05
         lda   (cmp1),y
         cmp   #$03
         bne   .next
         ldy   #$FF
         lda   (cmp1),y
         bne   .next
         tya
         sta   DiskIIArray-1,x
.next
         dex
         bne   .fingerprint
         rts
}

;-------------------------------
; NextSlot
;-------------------------------
!zone {
NextSlot
         lda   DRIVE
         cmp   #$31
         bne   .incslot
         lda   #$32
         sta   DRIVE
         bne   .done      ; unconditional branch
.incslot
         lda   #$31
         sta   DRIVE
         inc   SLOT
         lda   SLOT
         cmp   #$38
         bne   .nowrap
         lda   #$31
         sta   SLOT
.nowrap
         sec
         sbc   #$30
         tax
         lda   DiskIIArray-1,x
         beq   .incslot
.done
         lda   SLOT
         cmp   #$36
         bne   .reallydone
         lda   #$32
         sta   DRIVE
.reallydone
         rts
}

!zone {
ScanForRAMDisk
         lda   #$00
         sta   iunit
-        lda   iunit
         clc
         adc   #$10
         sta   iunit
         beq   .done
         cmp   #$80
         beq   -
         pha
         and   #$70
         lsr
         lsr
         lsr
         lsr
         tay
         pla
         ldx   DiskIIArray-1,y
         bne   -
         jsr   GetVolumeName
         bcs   -
         lda   OnlineReturn
         beq   -
         jsr   GetVolumeInfo

         ;watch for RAM disk type

         lda   filetype
         and   #$0F
         cmp   #$0F
         bne   -

         ;check for RAM[x] by name

         ldy   OnlineReturn
         cpy   #4
         beq   +
         cpy   #6
         bcs   -
         dey
+
--       lda   SlashRAM-1,y
         cmp   VolumeName-1,y
         bne   -
         dey
         bne   --

         ;check free space
         ;need at least $118 blocks

         sec
         lda   auxtype
         sbc   blocks
         tax
         lda   auxtype+1
         sbc   blocks+1
         cmp   #1
         bcc   -
         bne   +
         cpx   #$18
         bcc   -
+        lda   #TRUE
         sta   gUsingRAMDisk
.done
         rts

SlashRAM !byte $2F, $52, $41, $4D
}