v.doc	vers. 0.6   4/12/90	Bridger Mitchell (Plu*Perfect Systems)

	V -- quad-directional Z-System file viewer


V now supports multiple files, with usage:

	V filespec1 ... filespecN

A filespec is an ambiguous filename and type, preceded by an optional
DU: or DIR: specification.  Some valid filespecs are:

	*.DOC
	WORK:MENU??.TXT
	A15:*.*
	FOO.BAR
	
V maintains a ring of all matching files.  ^X will move to the
next file; ^R moves back to the previous file.  ^C exits the
program. Because the ring is virtual, V should work on any size
disk, regardless of the number of directory entries.  (These and all
other control commands may be rebound; see below).

A list of excluded filespecs is tested; files such as COM, REL, LBR,
!!!TIME&.DAT, etc. will be skipped automatically.  You can extend this
table by patching near the start of V.   

V uses an in-memory cache to make the most recently read sectors
of a file available for re-viewing without additional disk reads.
This allows  reverse viewing of crunched files, up to the limit
of available memory.  If, when going in reverse, the cache is
exhausted, V will automatically restart the uncrunching process
from the beginning of the file and display the first lines.

Viewing of adjacent lines/screens is rapid for both ascii and
crunched files.  Going to the End is also quick in ascii, but
results in some delay uncrunching a large file -- the entire
file must be uncrunched first.


		      TERMCAP requirements

The termcap requirement is the addition of three strings to the
standard Z-System termcap.  These definitions are already setup
in files of type ".NZT" (New Z-System Termcap), available on
major Z-Nodes.  If your terminal isn't already there, you can add
definitions following the initialization and deinitialization
strings.

NOTE:  This uses the STANDARD termcap specification (not the
one in experimental use in early 1989 by J. W. Wright).

Here's an example for the Wyse-50.

	DEFB	'TERMINALNAME'	; 13 bytes
	db	0		; reserved

	[ ... next part of termcap omitted...]

	DEFB	ESC,')',0	; SO - Standout on string
	DEFB	ESC,'(',0	; SE - Standout end string
	DEFB	0		; TI - Terminal init string
	DEFB	0		; TE - Terminal de-init string
;
; 3 extensions to standard TCAP follow immediately after "TE"
;
	DEFB	ESC,'R',0	; DL - Line Delete
	DEFB	ESC,'E',0	; IL - Line Insert
	DEFB	ESC,'Y',0	; CD - Clear to End of Screen String
;
; ... the rest of the termcap ...


			  CONFIGURATION

You can change the keys that control V by assembling a modified
version of the code below and 

;
; offsets from 100h for configuration areas
;
CONFIGBUF	equ	20h
HELPBUF		equ	80h
EXCLUDEBUF	equ	200h

SPACE	equ	20h
TAB	equ	09h
CR	equ	0dh
LF	equ	0ah

; 1. These are the bindings that control the V screen.  In addition
; to the one to three keys for each command, V automatically
; picks up the cursor-control keys ("arrow" keys) from the
; Z-System tcap and uses them, in addition to the bindings in
; these tables.
;
; 2.  To change the bindings, set the equates for your preferences,
; reassemble this file to HEX, and overlay onto V.COM.  
;
; 3. Enter exactly 3 bytes for each binding. Use uppercase for all
; keys.  V automatically converts a  typed lower case key to upper case.
; Use a nul to indicate the absence of a binding.
;
; 4. Edit the help screen to match your choice of bindings.
;
K_up1	equ	','
K_up2	equ	'P'-'@'	
K_up3	equ	0
; and, automatically, Z3TCP's left arrow key
;
k_pgup1	equ	'<'
K_pgup2	equ	TAB
K_pgup3	equ	'Z'-'@'
; and, automatically, Z3TCP's left arrow key

K_dn1	equ	'.'
K_dn2	equ	SPACE
K_dn3	equ	'N'-'@'
; and, automatically, Z3TCP's up arrow key

K_pgdn1	equ	'>'
K_pgdn2	equ	CR
K_pgdn3	equ	'V'-'@'
; and, automatically, Z3TCP's down arrow key
;
K_left1	equ	'L'
K_left2	equ	'A'-'@'
K_left3	equ	0
;
K_rt1 equ	'R'
K_rt2 equ	'E'-'@'
K_rt3 equ	0
;
K_beg1	equ	'B'
K_beg2	equ	0
K_beg3	equ	0
;
K_end1	equ	'E'
K_end2	equ	0
K_end3	equ	0
;
K_goto1	equ	'G'
K_goto2	equ	'S'
K_goto3	equ	0
;
K_nxtf1	equ	'X'-'@'
K_nxtf2	equ	0
K_nxtf3	equ	0
;
K_prvf1	equ	'R'-'@'
K_prvf2	equ	0
K_prvf3	equ	0
;
K_exit1	equ	'C'-'@'
K_exit2	equ	0
K_exit3	equ	0
;
;
subttl	'---------- KEY BINDINGS ----------'
;
; Each V function has three possible key values.
; V ignores case.
; If you use fewer than three keys, use nulls for the remainder.
;
;;	org	CONFIGBUF
;
beginconfig:
;
	db '__UP:'	
k.up:	db	K_up1,K_up2,K_up3	; Scroll one line up	
;
	db 'PGUP:'
k.pgup:db	K_pgup1,K_pgup2,K_pgup3	; Scroll one page (screen) up	
;
	db '__DN:'
k.down:	db	K_dn1,K_dn2,K_dn3	; Scroll one line down
;
	db 'PGDN:'
k.pgdown:db	K_pgdn1,K_pgdn2,K_pgdn3	; Scroll one page (screen) down
;
	db 'LEFT:'
k.left:	db	K_left1,K_left2,K_left3	; Scroll to left
;
	db 'RGHT:'
k.right:db	K_rt1,K_rt2,K_rt3	; Scroll to right
;
	db 'BEGN:'
k.begin:db	K_beg1,K_beg2,K_beg3	; Display beginning of file
;
	db '_END:' 	
k.end:	db	K_end1,K_end2,K_end3	; Display end of file
;
	db 'GOTO:'
k.goto:	db	K_goto1,K_goto2,K_goto3	; Goto (search) for string 
;
	db 'NXTF:'
k.nextfile:db	K_nxtf1,K_nxtf2,K_nxtf3	; View next file
;
	db 'PRVF:'
k.prevfile:db	K_prvf1,K_prvf2,K_prvf3	; View previous file
;
	db 'EXIT:'
k.exit:db	K_exit1,K_exit2,K_exit3	; Exit from V.
;

configlen	equ	$-beginconfig
;
test0 equ 	HELPBUF-CONFIGBUF-configlen
	ds	HELPBUF-CONFIGBUF-configlen	


subttl	'---------- HELP AND USAGE ----------'
;
;;	org	HELPBUF
;
; Edit the message to correspond to the key bindings.
;
helpmessage:
;
db 'V  commands (in addition to Z-System arrow keys):',cr,lf
db lf
db '1 line down  .  SP ^N       1 line up   , ^P',cr,lf
db '1 page down  >  CR ^V       1 page up   < ^Z',cr,lf
db 'n pages      digit          n pages     digit',cr,lf
db lf
db 'right        R              left        L',cr,lf
db 'beginning    B              end         E',cr,lf
db 'next file    ^X             prev. file  ^R',cr,lf
db 'goto/search  G              exit        ^C',cr,lf
db 0

;
helpmsglen equ $-helpmessage

;!!! ERROR -- help message is too long.

test2 equ 	EXCLUDEBUF-HELPBUF-helpmsglen
	ds	EXCLUDEBUF-HELPBUF-helpmsglen
;

subttl	'---------- FILE EXCLUSION LIST ----------'
;
;
exclude_cnt:
	db	??excnt		;; number of items in list

exclude_tbl:
; ruler:	'--11 bytes-'
	db	'!!!TIME&DAT'
	db	'????????SWP'
	db	'????????BIN'
	db	'????????C?M'
	db	'????????R?L'
	db	'????????Z?L'
	db	'?????????Y?'
	db	'????????LBR'
	db	'????????BSX'
	db	'????????RSX'
	rept	5*11		;; space for more
	db	0FFh		;; list terminator
	endm
??excnt equ ($-exclude_tbl)/11
	db	0
;
; end vkeys.lib