; 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	33

; There was still a problem with the way directories were logged in under
; BGii, because BGii, unlike Z33, will not accept the command DIR: to log
; in a password-protected directory that is within the allowed DU range and
; can be logged in using DU:.  Now I use the DU: form in this case.

;VERSION EQU	32

; Unfortunately, Bruce's code fails in an annoying way if the selected
; directory cannot be logged in using the forms DU: or DIR: (this is often
; the reason for using CD in the first place).  In such cases, the user will
; be asked to repeat a password that has already been entered correctly.
; I have modified the code to check for this situation.  If ZCPR33 is running,
; then its method of changing the default drive/user is used instead.  If not,
; then the code checks to see if DU: or DIR: will be accepted.  If so, that
; command line is prefixed to the multiple command line buffer.  Otherwise,
; the old login method using a warm boot is used.  The code now also checks
; for a completely illegal directory (e.g., a named directory with a nonloggable
; user number above 15).  In that case, the multiple command line is flushed.
;						Jay Sage, August 30, 1987

				; For ZCPR 3.3 & BGii compatilbility,
				; Also deleted vestigial (this ain't
				; CP/M 2 anymore...) messing with the
				; CPR user/drive byte and annoying
				; Warm Boots.
				; @20:56:07 April 10, 1987
				; Bruce Morgen

;VERSION EQU	31		; Responds to quiet flag.
				; ??/??/8? Joe Wright
Z3ENV	DEFL	0FE00H


;	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 and ASCII Equates

FCB	EQU	5CH
CR	EQU	0DH
LF	EQU	0AH


; Library Functions: SYSLIB, Z3LIB, Z33LIB

	EXTRN Z3INIT,Z3LOG,GETQUIET,PUTCL,DUTDIR,GETCL2,GETMDISK,GETMUSER
	EXTRN RETUD,EPRINT,EPSTR,COUT
	EXTRN MAFDC,PAFDC,INITFCB,F$EXIST
	EXTRN HIGHUSER,PDEFDU,Z33CHK,FCB1CHK


; Environment Definition

	 IF	Z3ENV NE 0

; External ZCPR3 Environment Descriptor

	JP	START
	DB	'Z3ENV'		; This is a ZCPR3 Utility
	DB	1		; External Environment Descriptor
Z3EADR:
	DW	Z3ENV
START:
	LD	HL,(Z3EADR)	; Pt to ZCPR3 environment

	 ELSE

; Internal ZCPR3 Environment Descriptor

	MACLIB Z3BASE.LIB
	MACLIB SYSENV.LIB
Z3EADR:
	JP	START
	SYSENV
START:
	LD	HL,Z3EADR	; Pt to ZCPR3 environment
	 ENDIF


; Start of Program -- Initialize ZCPR3 Environment

	CALL	Z3INIT		; Initialize the ZCPR3 Env
	LD	A,(FCB+1)	; Check for help
	CP	'/'		; Help?
	JP	NZ,CD		; Skip ahead if not

	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:
	CALL	Z33CHK		; See if we have ZCPR33
	JP	NZ,CD0		; If not, skip directory validity test
	CALL	FCB1CHK		; See if value directory given
	JP	Z,CD0		; If OK, skip message
	CALL	EPRINT
	DEFB	' Illegal directory specification.',0
	RET

CD0:
	LD	DE,FCB		; Point to FCB
	CALL	Z3LOG		; Login to DU

; Validate the directory if above user 15

	LD	A,(FCB+13)	; Get user number
	CP	10H
	JP	C,CD1		; If in range 0..15, skip ahead

	CALL	HIGHUSER	; See if Z33 and high users allowed
	JP	NZ,CD1		; If allowed, skip ahead

	CALL	EPRINT		; Display error message
	DEFB	' Illegal user area ',0
	LD	A,(FCB+13)
	CALL	PAFDC
	CALL	EPRINT
	DEFB	CR,LF,' All commands aborted.',0
	CALL	GETCL2		; Terminate pending commands
	LD	(HL),0
	RET
CD1:

; Add the ":ST" command to the command line if ST.COM exists in target
; directory

	LD	DE,STFCB	; Point to FCB for ST.COM
	CALL	INITFCB
	CALL	F$EXIST		; Does ST.COM exist?
	JP	Z,CD2		; If not, proceed with login of directory

	LD	HL,STCL		; Point to ":ST" command line
	CALL	PUTCL		; Add it to multiple command line
	JP	Z,CLERR		; Branch if overflow
CD2:

; Log into the new directory

	CALL	WRITEDU		; Form command of form DU:<0>
	CALL	GETQUIET	; Display messages only if not quiet flag
	JP	NZ,QUIET1
	CALL	EPRINT
	DB	' Logging Into ',0
	LD	HL,LOGCL	; Point to "DU:" string
	CALL	EPSTR
QUIET1:	

	CALL	RETUD		; Get user/drive
	CALL	DUTDIR		; Convert DU to DIR
	JP	Z,LOG		; Branch if directory has no name

	LD	DE,LOGCL	; Copy directory name into LOGCL
	LD	B,8		; Maximum of 8 characters in name
PRTNAME:
	LD	A,(HL)		; Get character from NDR
	CP	' '		; Done?
	JP	Z,LOG
	LD	(DE),A
	CALL	GETQUIET
	LD	A,(DE)		; Restore character
	CALL	Z,COUT
	INC	HL		; Point to next
	INC	DE
	DEC	B		; Count down
	JP	NZ,PRTNAME

LOG:
	EX	DE,HL		; Switch LOGCL pointer to HL
	LD	(HL),':'	; Add colon to command line
	INC	HL
	LD	(HL),0		; Terminate LOGCL

; Log in directory:  This is done either by putting drive/user into the
; message buffer (if Z33) or by putting DU: or DIR: in the command line (if
; allowed) or by putting drive/user into page 0 and warm booting (if nothing
; else will do the job).

	CALL	RETUD

		; Check for ZCPR33

	CALL	Z33CHK
	JP	NZ,NOTZ33
	CALL	PDEFDU		; Make current DU the default
	RET			; That's all!

		; Check whether directory can be logged into
		; ..using DU: or DIR: forms.

NOTZ33:
	CALL	DUTDIR
	JP	Z,CHKDU		; If no name, check the DU value
	LD	DE,8		; Offset to password
	ADD	HL,DE
	LD	A,(HL)		; See if there is a password
	CP	' '
	JP	Z,USECL		; If not, we can use the DIR: command line

CHKDU:
	CALL	WRITEDU		; Get "DU:<0>" back into LOGCL
	CALL	GETMDISK	; See if drive in range
	DEC	A		; Shift to range 0..15
	CP	B
	JP	C,BOOTLOG	; If out of range, no choice but to warm boot
	CALL	GETMUSER	; See if user in range
	CP	C
	JP	C,BOOTLOG		; If not, no choice but to warm boot

USECL:
	LD	HL,LOGCL	; Point to command line of form DU: or DIR:
	CALL	PUTCL		; Store it in ZCPR3 CL Buffer
	RET	NZ		; If no overflow, we are done

CLERR:
	CALL	GETQUIET
	RET	NZ
	CALL	EPRINT		; Print error message
	DB	' Command Line Overflow',0
	RET

BOOTLOG:
	LD	A,C		; Shift user into high nibble
	RLCA
	RLCA
	RLCA
	RLCA
	OR	B		; Join with drive in low nibble
	LD	(4),A		; Store in user/drive byte in page 0
	JP	0		; Warm boot to log it in

; Subroutine to write "DU:<0>" into the LOGCL buffer

WRITEDU:
	CALL	RETUD		; Get DU into BC
	LD	DE,LOGCL	; Point to destination
	LD	A,B		; Get drive
	ADD	A,'A'		; Convert to letter
	LD	(DE),A
	INC	DE
	LD	A,C		; Get user number
	CALL	MAFDC
	EX	DE,HL
	LD	(HL),':'	; Put in the colon
	INC	HL
	LD	(HL),0		; And the null
	RET

	DSEG

; Buffers

LOGCL:
	DS	10		; Enough for any DU: or DIR: and null
STCL:
	DB	':ST',0

STFCB:
	DB	0,'ST      COM'	; Default command FCB
	DS	24
	END