;
                                   DU3.COM                                    
   
             Size (recs) CRC   Version    Author/Latest Issue      Disk
DU314.COM     12k (89)   801A  1.4        Carson Wilson 1/88       Z3COM4
DU34.COM      16k (123)  45F8  4.0        Gorm Helt-Hansen 1/91    Z3COM4

  1- Syntax/Patch  2- Permanent Macros  3- Notes  4- Help File  5- DU3.HLP    


   Disk  Utility  provides full screen-oriented direct disk  editor  features.
Four  screens of command information are internally available by  typing  "?".
DU34.COM is DU314.COM modified for use with  ZCPR33 and  Z3PLUS.   See DU3.HLP
for details on usage.  

   DU3 Vs 1.0 (6/84) by R. Conn.   DU34 is derived from  DU3  Version 1.4  and
DU88;  DU3 is derived from DU2 Version 1.1;  DU2 is derived from DUTIL Version
1.1; DUTIL is derived from DU Version 7.5 (1/23/81) by Ward Christensen.
:1
    Syntax   DU3               <-- enter DU3 at command level
             DU3 cmd line      <-- run initial DU3 command line

   Erased directories  are removed while  reading directory  tracks to memory. 
This reduces the amount of space needed for directory mapping on hard disks.
                                DU314PAT.HEX 

             Size (recs) CRC   Version    Author/Latest Issue      Disk
               1k (5)    C13F  n/a        Carson Wilson            Z3COM2
==============================================================================

   DU314PAT is  a  hex file  to load over  DU3 version 1.4  (from  DU314.LBR), 
which fixes some inaccuracies in DU's help screen. 
:2
 Permanent Macros 

   A Permanent  macro  facility  allows  DU3 to  be loaded with macros already 
defined and ready to use.  The following initial macros are defined:

            0:  G0,D          <-- go to first record of dir and display it
            1:  -D            <-- display previous record
            2:  +D            <-- display next record
            3:  -8D           <-- back up 8 records and display
            4:  +8D           <-- skip forward 8 records and display 
            5:  T0,S1,D       <-- display first disk sector
            6:  +D,*          <-- forward one sector, display, repeat
            7:  D,<B,+,*      <-- display, put in queue, forward, repeat 
:3
 DU3 Notes - 1/2 

   a. Version 4.0 updates (1/5/91, Gorm Helt-Hansen):
      - New code added and old changed. Modelled by DU88 to make DU3 work with
        Z3PLUS,  which is used  under  CP/M 3.x.   All  direct  BIOS calls are
        directed via  BDOS  under  Z3PLUS.   A version check is  added,  so it
        should work unchanged with other versions of ZCPR3.

   b. Version 1.4 updates (1/1/88, Carson Wilson):
      - Map command now packs the directory,  removing  erased  entries.  This
        should allow larger disks to be mapped, and also should form the basis
        for the more powerful directory  packing  scheme suggested by Jay Sage
        in DU314.UPD.
      - Fixed max. user number bug.  Unn command was giving error for ZCPR ENV
        max user of nn.
      - Added permanent macros to version 1.3CW.
      - Directory timestamps no longer recognized in Map command.
      - DJNZ macro reinstated because its removal was causing trouble. 
      - Adapted DU313CW help screens for reverse video. 
      - Now links with DSEG.
 DU3 Notes - 2/2 

   c. Version 1.3 updates (9/11/87, Jay Sage, Carson Wilson):
      - Modified to incorporate a set of  permanent macros.   These macros can
        be invoked by the command tail when DU is invoked.   They  are  copied
        from a space of 128 bytes near the beginning of the code.  The area is
        identified by a string of text to facilitate patching.  The macros are
        listed one after another,  separated by  carriage  return  characters.
        Macros that are not to be defined  must be present as carriage returns
        alone or the macros will fail.   The help screen code  was  pulled out
        into an include file and modified to give a reasonable appearance on a
        reverse-video screen.
      - Translated to Z80 opcodes and lower case. 
      - Allowed disks with directory time stamps with map command.
      - Added "," and "." for edit plus/minus block command.
      - Replaced help completely.
      - Cleaned up various displays.
      - Removed djnz macro, so for Z80 cpu only.  
      - Removed embedded tabs from db opcodes.  
:4
                                 DU3.HLP 

             Size (recs) CRC   Version    Author/Latest Issue      Disk
              38k (300)  B790  n/a                                 Z3HLP3
==============================================================================

   Z-System help file for Disk Utility DU3.
:5 :DU3


;
; DATE:  20 Apr 86
; PREVIOUS VERSIONS:  1.0 (20 June 84) , 1.1 (22 Oct 84),
; NOTE:  DU3 must be assembled using M80 (or equiv)
;
	.Z80
vers	equ	14		; <crw>

z3env	equ	0fc00h

;
;  DU3 is derived from --
;	  DU.ASM  V7.5	Revised 1/23/81
;	DISK UTILITY - By Ward Christensen
;
;  Principal Authors of DU V7.5 are --
;	WLC   KBP   RGF   BRR
;
;  Key comments from DU V7.5 and DU3 follow --
;
;This version of DU is compatible with CP/M 2.x
;and does not require alteration for various hardware
;configurations.  It adjusts itself automatically to
;the correct number of sectors, tracks, directory size,
;etc.  It has been tested on 5-1/4" and 8" floppy, and
;10 megabyte hard disk systems.
;
;Because of the automatic adaption feature, no conditional
;assembly options are included.
;
;*************************************************
;* 						 *
;*   This program has been heavily modified	 *
;* to allow it to work without modification	 *
;* on all versions of CP/M 2.x.			 *
;*   One known possible problem involves the	 *
;* system tracks on some systems, and results	 *
;* from the system sectors being skewed. There	 *
;* is NO way for a program executing under CP/M	 *
;* to know about this.  This program assumes the *
;* standard convention of no skew being used on	 *
;: the system tracks. This usually isn't a prob- *
;* lem because the SYSGEN program can be used to *
;* get the system from the disk so that	it can	 *
;* be modified.					 *
;* 						 *
;* 		Ron Fowler			 *
;* 						 *
;*************************************************
;

;
;  SYSLIB and Z3LIB References ( Also VLIB - jgm )
;
;  Proper order of link:
;
;	L80 du314/n,du314/p:100/d:2e00,vlib/s,z3lib/s,syslib/s,/e
;		(Link modified from SRLNK to L80   G.H-H.)

