.z80
; PRL/RSP to display DRVTBLE and SWAP DPH's - COM file

bdos	equ	0005h
dfcb1	equ	005ch
dfcb2	equ	006ch
dbuff	equ	0080h

	dseg

rsxpb:	db	127	; Function number
	db	0	; Set to 1 parameter for SWAP
	dw	0

notplus:	db	'SWAP: ? Requires CP/M 3.1$'
query:	db	'SWAP: ? Bad drives$'

	cseg

	ld	c,12	; version
	call	bdos
	cp	31H
	ld	de,notplus
	ld	c,9
	jp	nz,bdos

	ld	a,(dbuff)	; test command taile
	or	a
	jr	z,gorsx		; -empty-

	ld	hl,rsxpb+1
	ld	(hl),1

	ld	a,(dfcb1)
	dec	a
	jp	m,error
	inc	hl
	ld	(hl),a

	ld	a,(dfcb2)
	dec	a
	jp	m,error
	inc	hl
	ld	(hl),a

gorsx:
	ld	de,rsxpb
	ld	c,60
	jp	bdos		; Call RSX

error:	ld	de,query
	ld	c,9
	jp	bdos

	end