;
; Program:  CD
; Version:  3.0
; Author:  Richard Conn
; Date: 12 Apr 84
; Previous Versions: None
; Derivation: In Concept from CD 2.4 for ZCPR2
;
version	equ	30
z3env	set	0f400h

;
;	CD is used to log into a new directory by name or DU (DIR or DU forms)
; and to automatically run ST once there if it is available.
;
;	Syntax:
;		CD or CD //	<-- Print Help
;		CD dir:		<-- Log In and Run ST.COM
;

;
; OS Equates et al
;
cpm	equ	0
udbyte	equ	4
bdos	equ	5
fcb	equ	5ch
tbuff	equ	80h
tpa	equ	100h
cr	equ	0dh
lf	equ	0ah

;
; SYSLIB and Z3LIB Functions
;
	ext	z3init,z3log
	ext	retud,moveb,initfcb,putcl,eprint,pafdc,cout,dutdir

;
; Environment Definition
;
	if	z3env ne 0
;
; External ZCPR3 Environment Descriptor
;
	jmp	start
	db	'Z3ENV'	;This is a ZCPR3 Utility
	db	1	;External Environment Descriptor
z3eadr:
	dw	z3env
start:
	lhld	z3eadr	;pt to ZCPR3 environment
;
	else
;
; Internal ZCPR3 Environment Descriptor
;
	MACLIB	Z3BASE.LIB
	MACLIB	SYSENV.LIB
z3eadr:
	jmp	start
	SYSENV
start:
	lxi	h,z3eadr	;pt to ZCPR3 environment
	endif

;
; Start of Program -- Initialize ZCPR3 Environment
;
	call	z3init	;initialize the ZCPR3 Env and the VLIB Env
	lda	fcb+1	;check for help
	cpi	'/'	;help?
	jnz	cd
	call	eprint
	db	'CD, Version '
	db	(version/10)+'0','.',(version mod 10)+'0'
	db	cr,lf,'Syntax:'
	db	cr,lf,'  CD dir:  or  CD du:  <-- Change Directory'
	db	0
	ret
;
; Log into DU converted by ZCPR3
;
cd:
	lxi	d,fcb	;pt to FCB
	call	z3log	;login to DU
	call	retud	;set DU in the UD byte
	mov	a,c	;set user
	rlc		;rotate right 4 bits
	rlc
	rlc
	rlc
	ani	0f0h	;mask
	mov	c,a	;save for now
	mov	a,b	;get disk
	ani	0fh	;mask
	ora	c	;mask in user
	sta	udbyte	;save value in UD byte
;
; Print New Directory
;
	call	eprint
	db	' Logging Into ',0
	call	retud	;get DU in BC
	mov	a,b	;get disk
	adi	'A'
	call	cout
	mov	a,c	;get user
	call	pafdc	;print number
	mvi	a,':'	;print colon
	call	cout
	call	dutdir	;convert to name
	jz	runfile	;run file if no name
	mvi	b,8	;8 chars max to name (pted to by HL)
prtname:
	mov	a,m	;get name char
	cpi	' '	;done?
	jz	runfile
	inx	h	;pt to next
	call	cout
	dcr	b	;count down
	jnz	prtname
;
; Look for File
;
runfile:
	lxi	h,stfile	;pt to FCB
	lxi	d,fcb		;copy into FCB
	mvi	b,12		;12 bytes
	call	moveb
	call	initfcb		;init FCB
	mvi	c,15		;try to open file
	call	bdos		;use BDOS
	cpi	0ffh		;not found?
	jz	cpm		;done - no ST.COM
	lxi	h,stcl		;pt to default command line
	call	putcl		;store it in ZCPR3 CL Buffer
	jnz	cpm		;abort to OS if done
	call	eprint		;print error message
	db	' Command Line Overflow',0
	jmp	cpm

;
; Buffers
;
stfile:
	db	0,'ST      COM'	;default command
stcl:
	db	'ST',0		;default command line

	end