; UNARCZOV.ASM
;
; Overlay File for UNARCZ -- ZCPR3 Archive File Extractor -- Version 1.0
;
; The file was modified from the overlay file for UNARC version 1.6, which
; is copyright (C) 1987 by Robert A. Freed.  All rights reserved.
;
; This file may be used to customize the UNARCZ for specific non-universal
; requirements.  It is intended primarily for RCP/M system operators or
; technically-oriented users with specialized system requirements.  Use
; only with the UNARCZ version indicated above.
;
; The distributed program files are suitable for the majority of users
; with standard ZCPR3 or Z3PLUS operating environments.
;
;=======================================================================
;
; To use, simply follow these three steps:
;
; 1) Edit this UNARCZOV.ASM file for desired options.
; 2) Assemble to create an UNARCZOV.HEX file.
; 3) Merge with the distributed UNARCZ.COM program file.
;
; ASM, the assembler supplied with CP/M 2.2, or MAC, the assembler supplied
; with CP/M Plus, may be used for assembly.  Likewise, DDT or SID may be
; used for the final step (if you save the correct number of memory pages),
; but the publicly-distributed program MLOAD.COM (by Ron Fowler, Nightowl
; Software, Inc.) is recommended:
;
;	A>MLOAD UNARCZ.COM,UNARCZOV
;
;=======================================================================
;
NO	EQU	0
YES	EQU	NOT NO
;
; Most UNARCZ program options are specified by equate statements below.
; Each option is followed by a detailed description of its function.
; Most of these options are provided for RCP/M systems, and those most
; commonly changed are marked with an asterisk "*" in the comment field.
; (The other option defaults are suitable for the majority of systems.)
;
RCPM	EQU	NO		; *YES if remote CP/M system
;
; RCPM -- Define RCPM = YES to generate a restricted version of UNARCZ for
; secure use by callers of an RCP/M remote access system.  "Restricted"
; implies that no disk file extraction can be performed.  Also, the P
; (print) and C (check archive) command line options are ignored.  In
; addition, file typeout may be disallowed (see TYFLG) or limited to a
; maximum number of lines (see TYLIM), and the default interpretation of
; certain other parameters is modified (see TYPGS and BLKSZ).
;
; WHEEL -- As of UNARCZ 1.7, the WHEEL byte is always checked.  The address
; of the wheel byte is obtained from the Environment Descriptor.  It is no
; longer necessary to configure UNARCZ to check the wheel byte or to patch in
; the address.
;
; USEWHL	EQU	YES		; YES to use wheel byte
; WHEEL		EQU	003EH		; Wheel byte address
;
; If the wheel byte is reset (0) the same version of UNARCZ may be utilized
; for restricted use by remote callers as is used by the sysop when the
; wheel byte is set.  Subsequent references to the "restricted" version of
; UNARCZ below apply only when the wheel byte is zero; when the wheel byte
; is set, operation of UNARCZ is identical to that obtained by defining
; defining RCPM = NO above.
;
; The following two definitions apply only in restricted versions:
;
TYFLG	EQU	YES		; NO to disallow RCP/M file typeout
;
TYLIM	EQU	0		; *Non-zero typeout line limit (1-255)
;
; TYFLG and TYLIM -- Define TYFLG = NO to disallow file typeout operations on
; RCP/M systems.  In this case, UNARCZ may be used only to obtain directory
; listings of archive files; in which case, it may be more appropriate to
; rename the program "ADIR" (see program name patch at end of this file).  If
; TYFLG = YES (the normal case), TYLIM may be defined as the non-zero limit
; (255 maximum) of the number of file lines which may be displayed.  This
; may be desired by some RCP/M sysops to discourage excess on-line "browsing"
; in favor of downloading of long files by callers.  If TYLIM = 0, unlimited
; file typeout is permitted as in unrestricted versions.
;
CCPSV	EQU	8		; No. high memory pages to save (8 = 2K)
;
; CCPSV -- UNARCZ uses all available TPA space for buffering output files,
; which provides better performance in systems with larger memories.  However,
; by default the program preserves the CPR area at the top of the TPA, and
; it returns directly to the CPR instead of forcing a warm boot after
; execution.  CCPSV specifies the amount of memory (256-byte pages) to
; reserve for this purpose.  The default value (CCPSV = 8) is appropriate for
; the CPR size in standard ZCPR3 systems.  Setting CCPSV = 0 will yield an
; additional 2K bytes of buffer space, but it forces a warm boot return after
; each program execution.  This need be used only on systems with very small
; TPA's, but it may be desirable with CP/M 3.0, XBIOS on the SB180, or with
; any system with a permanently-resident CPR.  Some non-standard systems
; may require may require the CCPSV = 9, etc.
;
TYPGS	EQU	0		; No. buffer pages for typeout (0=max)
;
; TYPGS -- This value specifies the number of (256-byte) pages to buffer an
; extracted file during typeout operations.  The default definition
; (TYPGS = 0) provides the maximum possible buffering (the entire TPA space),
; but may cause a long delay at the start (and in the middle) of typeout of
; large files.  Defining TYPGS = 1 will minimize viewing waits, but may cause
; excessive start/stop of floppy disk drive motors on some systems (e.g.,
; 1983 Kaypro models).  Since this is not a consideration for systems with
; hard disks, users of such systems may prefer TYPGS = 1.  For restricted
; RCP/M versions, TYPGS = 1 is assumed if the default (TYPGS = 0) is not
; changed (to minimize delays for remote users).  The TYPGS definition may
; be overridden by the USELUX equate following:
;
USELUX	EQU	NO		; *YES if UNARCZ will be used by LUX
;
; USELUX -- Some versions of the LUX library/archive utility program fail to
; properly protect the resident code which LUX relocates to high memory before
; calling UNARCZ.  This may be due to a problem of interaction between LUX and
; the BYE5 RCP/M monitor program.  The result can be a system crash during
; typeout of an archive member file with the LUX TYPE command.  Define
; USELUX = YES to avoid this problem.  This forces the minimum TPA buffering
; during file typeout (equivalent to defining TYPGS = 1), in both restricted
; and unrestricted versions.  Versions of UNARCZ which have been modified by
; this definition may be distributed with LUX, providing notice is given
; explaining that this modification may not be suitable for non-LUX environ-
; ments and encouraging LUX users to upgrade to newer releases of UNARCZ as
; they become available.
;
BLKSZ	EQU	0		; Default disk allocation block size (in K)
;
; BLKSZ -- This value provides the default disk allocation block size (as a
; multiple of 1K bytes) to use in calculating disk space requirements for
; the "Disk" column of archive directory listings (except during file
; extraction to disk, in which case the output drive's block size applies.)
; The default definition (BLKSZ = 0) indicates that the block size of the
; default drive is to be used for this purpose.  However, for restricted
; RCP/M versions, BLKSZ = 1 is assumed if the default is not changed.  Since
; 1K is the minimum disk block size in any CP/M-compatible system, this
; provides the widest applicability for all remote callers, independent of
; the RCP/M system's actual disk block size.
;
CPM68K	EQU	NO		; YES if BDOS function 31 not supported
;
; CPM68K -- UNARCZ uses BDOS function 31 (Get Address of Disk Parameter Block)
; to determine disk allocation block size (i.e., of the output drive when
; extracting files to disk, or of the default drive at other times, if
; BLKSZ = 0).  However, this function is rarely used by application programs
; and is not supported by some non-standard implementations of CP/M (in
; particular, the 8080 CP/M 2.2 emulator for CP/M-68K).  For such systems,
; define CPM68K = YES to inhibit use of BDOS function 31.  In this case,
; the BLKSZ value will be assumed (1K, if BLKSZ = 0).  (This option probably
; had no application on ZCPR3 systems.)
;
HIDRV	EQU	'P'-'@'		; Highest input file drive (A=1, B=2, ...)
;
; HIDRV -- Specifies the highest accessible drive for archive file input,
; where drive A is 1, drive B is 2, etc.  The default definition of 16
; ('P'-'@') is the maximum supported by CP/M-compatible systems.  Most RCP/M
; systems need not alter this definition, this definition, since invalid
; drive accesses are normally intercepted elsewhere.  If this is not the
; case, this value should be set to the number of available drives (assuming
; all drives are available in sequence from drive A).  Setting HIDRV = 0
; restricts input to the default drive (i.e., disallows specification of a
; drive for the archive file).
;
HIUSR	EQU	15		; Highest input user area (1..31  or 0)
;
; HIUSR -- Specifies the highest accessible user area for archive file input.
; The default is 15, but it may be set as high as 31.  HIUSR = 0 does not
; make users 1-31 inaccessible, it merely restricts the archive file to the
; currently logged user area.  This feature is primarily for RCP/M's, which
; will restrict access to specific user areas by other methods.
;
HODRV	EQU	'P'-'@'		; Highest file output drive
;
; HODRV -- Specifies the highest allowable output drive no. for file extrac-
; tion (similar to HIDRV above).  Setting HODRV = 0 will disallow any file
; extraction to disk, which is the obvious setting of importance for RCP/M
; systems.  Restricted versions restrict file output anyway, when the WHEEL
; byte is zero, so this value need not be modified, except for local use,
; if RCPM = YES above.
;
HOUSR	EQU	15		; Highest file output user
;
; HOUSR -- Specifies the highest accessible user area for archive member file
; extraction and works just like HIUSR.  The default is 15, but it may be set
; as high as 31.  HOUSR = 0 does not make users 1-31 inaccessible, it merely
; restricts the archive file to the currently logged user area.  This feature
; is primarily for RCP/M's, which will restrict access to specific user areas
; by other methods.
;
TYLPS	EQU	23		; Number of screen lines before pause (1-255)
;
; TYLPS -- Specifies the number of lines between automatic pauses during
; console typeout.  Should be set to one less than the number of display
; screen lines, to allow for the "[more]" message line.  Setting TYLPS = 0
; will inhibit all pauses (e.g., for hard-copy terminals), although this can
; also be specified by a trailing "N" option on the UNARCZ command line.
;
BELLS	EQU	YES		; NO to inhibit bell on error
;
; BELLS -- By default (BELLS = YES), the terminal "bell" (i.e., beeper) is
; sounded as warning and fatal error messages are printer, to bring operator
; attention to unusual conditions.  Define BELLS = NO if you prefer solitude.
;
;                    (End of user-definable equates)
;=======================================================================
;                      (Start of program patches)
;
; Do not make any changes to this section.  Additional user-definable options
; continue below the next double separator line.
;
	ORG	108H
;
	DB	CCPSV		; 10BH
	DB	BLKSZ		; 10CH
	DB	HIDRV		; 10DH
	DB	HIUSR		; 10EH
	DB	HODRV		; 10FH
	DB	HOUSR		; 110H
;
	DB	TYFLG AND 0FFH	; 111H
;
	 IF NOT USELUX
	DB	TYPGS		; 112H
	 ENDIF
	 IF USELUX
	DB	1		; 112H
	 ENDIF
;
	DB	TYLIM		; 113H
;
	DB	TYLPS		; 114H
;
	 IF NOT CPM68K
	DB	0		; 115H
	 ENDIF
	 IF CPM68K AND BLKSZ
	DB	BLKSZ		; 115H
	 ENDIF
	 IF CPM68K AND NOT BLKSZ
	DB	1		; 115H
	 ENDIF
;
	DB	BELLS AND 0FFH	; 116H
;
;=======================================================================
;          (Additional user-definable patches continue here)
;
; The following is a table of filetypes (3-byte ASCII strings) which are
; assumed to contain binary data and are not allowed for file typeout.
; Question marks may be used as wildcards (will match any character).
; The table must terminate with a zero byte (room for 20 entries total).
;
	DB	'COM'		; CP/M-80 or MS-DOS binary object	117H
	DB	'CM','D'+80H	; CP/M-86 binary object (or dBASE file)
	DB	'EXE'		; MS-DOS executable
	DB	'OBJ'		; Renamed COM
	DB	'OV?'		; Binary overlay
	DB	'REL'		; Relocatable object
	DB	'?RL'		; Other relocatables (PRL, CRL, etc.)
	DB	'INT'		; Intermediate compiler code
	DB	'SYS'		; System file
	DB	'BAD'		; Bad disk block
	DB	'LBR'		; Library
	DB	'ARC'		; Archive (unlikely in an ARC)
	DB	'ARK'		; Alternate archive (ditto)
	DB	'?Q?'		; Any SQueezed file (ditto)
	DB	'?Z?'		; Any CRUNCHed (or ZOO'd) file (ditto)
;
; Additional filetypes may be added below.  To remove one of the above file
; types without replacing it, simply set the MSB in any byte (as above for
; CMD, since that can be a readable ALIAS script file or dBASE command file).
;
	DB	0,0,0							144H
	DB	0,0,0
	DB	0,0,0
	DB	0,0,0
	DB	0,0,0
	DB	0		; End of table (do not change)		153H
;
; The following 6 bytes specify the program name for self-referential
; use in the help display and abort message.  If less than 6 name
; characters are desired, the remaining bytes must be padded with blanks.
;
	DB	'UNARCZ'	; Author's preference			154H
;	DB	'ADIR  '	; (But some sysops may prefer this)
;
; If you prefer to call this program "ADIR" (Archive Directory), move the ";"
; up one line above.
;
;=======================================================================
;
LAST	EQU	$-1		; 160H	Last patch address
;
; Confirm that the symbol LAST has the value 160H, which is the highest
; program location which may be modified in UNARCZ.COM.
;
	END