SPZ is a full screen interactive disk update utility, providing
many of the features found in DU.COM. The program is menu
driven, and little additional documentation is required. The
following notes consist of a functional overview, plus notes on
features not documented in the menus.
SYSTEM REQUIREMENTS.
SPZ requires a Z80 - it may be possible to update the source for
8080 but extensive use is made of Z80 opcodes, and this would be
a large exercise. Subroutines would be required to simulate
LDIR, LDDR, and CPIR, to say nothing of varieties of shift,
rotate and load instructions.
CP/M 2.x is required.
One or more disks may be used - SPZ determines if a selected disk
is defined in the BIOS before attempting to access it.
The terminal used must support cursor addressing, clear screen,
and erase to end of line. At least an 80 by 24 display is
required.
FACILITIES.
SPZ enables disk sector editing in HEX or ASCII, using File
Relative or Track/Sector addressing. In File Relative mode a
sorted directory listing is used to select the file. In both
modes forward and backward browse is provided, in addition to
random record selection. The displayed sector may be copied to a
scratchpad buffer, or exchanged with the scratchpad. The
directory list may be full (*.*) or selective, eg. *.ASM and the
selection may be changed at any time.
A file TYPE facility gives a paged, formatted display of any
file. Control characters are displayed as "." except for TAB and
Carriage return/Line feed which are processed normally. .COM
files are not formatted.
The SPZ command format may enter any operational mode directly -
SPZ enters SPZ with a *.* directory list.
SPZ d: as above with d:*.* directory list.
SPZ [d:]afn as above with d:afn directory list.
SPZ [d:]ufn enters SPZ in file relative mode, using the
specified file.
SPZ [d:]DSK: enters SPZ in Track/Sector addressing
mode on the specified drive.
DIRECTORY LIST MODE.
In directory list mode the cursor is positioned on the first
filename displayed. The cursor can be moved LEFT, RIGHT, UP or
DOWN using Control keys. A file is selected by typing a command
character against the required file name - "E" for file relative
editing, or "T" for the TYPE function.
Up to 32 file names are listed. If there are more files, the
directory list may be paged forward and back.
Other drives may be selected or the current disk changed. NOTE:
if the disk in the current drive is changed, the "change disk"
function should be used to select the same drive again. This
provides a new directory list, and avoids CP/M making the disk
Read Only.
Track/Sector addressing is selected from the directory list
display.
The directory list selection may be changed - the default is *.*
unless set by the SPZ command.
FILE RELATIVE MODE.
In this mode the selected file is displayed in HEX and ASCII
format with record number and file offset displayed. For .COM
files the address when loaded at 0100H is diplayed.
The record displayed may be selected by browsing forward and
back, locating the first or last record, or by setting a record
number (in HEX). When setting a record number, Hex digits are
entered in "calculator style" - new digits are entered on the
right while the number moves left. Backspace deletes the last
digit entered, and Escape restores the original number. These
features are common to all number entries in SPZ. The selected
record is read when RETURN is pressed. If it is not found, the
previous record number will be restored.
The displayed record may be changed by typing "C". The cursor is
positioned on the first hex digit, and is moved using the same
control keys as are used in the directory list mode. Any valid
hex digit may be typed to alter the record. The TAB key moves
the cursor to its corresponding location in the ASCII display,
allowing character strings to be easily changed. Another TAB
returns the cursor to the HEX display area.
Two control codes are available to stop editing the record; one
saves the changes and rewrites the record to disk, the other
restores the record to its original contents.
Return to directory list mode is made by typing "L".
TYPE FILE
Files are TYPEd with up to 72 characters per line, 18 lines per
page. Except for .COM files, Carriage return/Line feed codes are
honoured, and Tabs are expanded. All other control characters
are displayed as "." to prevent unwanted terminal control
functions.
Forward and backward paging operations are provided, including
return to top of file. Following paging, the highest page
displayed can be restored.
DIRECTORY LIST SELECTION.
The ambiguous file name used for the directory list may be edited
by typing "M" in the directory list mode display. The existing
file NAME and TYPE may be overwritten or edited using INSERT and
DELETE control keys. Only those characters defined as legal in
the CP/M documentation are permitted.
If "*" is typed at any point in the NAME or TYPE, the remainder
of the field will be filled with "?". If a SPACE is typed the
remainder of the field will be blanked out. Period also has this
effect if used in the NAME field - an ambiguous file name may
thus be entered in the normal fashion.
The TAB key switches between editing the NAME and TYPE.
The ESCAPE key restores the original selection, RETURN produces a
new directory list.
NOTE - insert and delete affect only the field being edited, -
characters do not wrap between name and type.
TRACK/SECTOR ADDRESSING.
This mode is entered by typing "S" in directory list mode. The
facilities provided here are similar to File Relative mode, but
sectors are selected by setting (or browsing back and forward)
track and sector numbers. The allocation block number is also
displayed and may be set. When a block number is set, the first
sector of that block is displayed. The record diplayed may be
altered in the same manner as File Relative mode. The scratchpad
facility is also available in this mode. Note that sectors saved
in one mode are available for exchange in the other mode.
INSTALLATION
SPZ uses the following terminal facilities -
Cursor Addressing
Clear Screen
Erase to end of line
SPZ assumes that the cursor is positioned by a prefix string
followed by ROW+020H, COLUMN+020H. If this is not the case for
your terminal you must update routine CURS and reassemble and
link SPZ.
The cursor positioning prefix, and other functions may be altered
using DDT, or preferably a Z80 debugger.
NOTE: The following addresses are NOT correct for the version of
SPZ.COM distributed on this disk! I am leaving the text below
unaltered for historical reasons but have added what appears to
be true for the assembled code distributed with this
documentation. This is a classic case of not having the source
code for the executable program. I am also not convinced this
documentation file is describing version 3.3 of SPZ, but it's
probably pretty close. (Lee Bradley, August 13, 1989)
NOTE: Here's what I have found to be the case for the assembled
code distributed with this version:
At location 150H the first byte holds the number of bytes in the
clear screen sequence, which follows. For the distributed
version (Kaypro compatible), this is 01 1A. (CTRL-Z).
At location 158H the first byte holds the number of bytes in the
clear to end of line sequence, which follows. For the
distributed version (Kaypro compatible), this is 01 18. (CTRL-X).
At location 170H the first byte holds the number of bytes in the
cursor lead in (for cursor positioning), which follow. For the
distributed version (Kaypro compatible), this is 02 1B 3D.
(ESC =).
At location 180H you will find the values 01 20 20 01, which
appear to have something to do with the offset needed by the
cursor positioning codes. Probably need to leave these alone.
I have also edited SPZ.COM to make it run on a Royal AlphaTronic
computer, which is VT52 compatible (sort of). I have a color
monitor and decided to make the clear screen sequence give me a
white foreground and blue background. The codes I used follow:
At 150H (clear screen with white foreground, blue background)
I put 04 1B 54 37 31. (ESC T 7 1).
At 158H (clear to end of line) I put 02 1B 4B. (ESC K)
At 170H (cursor positioning leadin) I put 02 1B 59. (ESC Y).
The control keys used for cursor movement are defined by equates
in the assembler source and may be altered if desired. The menus
will reflect any changes made to these equates.
SPZ.MAC
Several Macros are used in the SPZ assembly. These are provided
inline.
$RTN
is used to head each subroutine. It generates a label (using DS
0 because Microsoft seem to think EQU statements do not need to
be listed in the Macro expansion [Ah well, it takes all kinds
..]). An entry statement is also generated so that the L80 /Y
option will provide symbols for ZSID.
$PANEL
generates a call to the panel display subroutine, passing a panel
name as a parameter.
$NPANEL
does the same, but first clears the screen.
$FLD
generates a call to the field display subroutine.
$IFLD
same as $FLD, but also inputs a character and converts to upper
case.
$STRO
prints the specified string.
$HEXW
prints a 4 byte HEX number.
$MTCH
calls the string search function.
$EXVA
calls the vectored call function.
CONTROL CODE EQUATES.
A set of EQU statements is provided to change the control codes
used throughout SPZ. These EQUates are also used in the menus,
hence changes to these will correctly update displayed messages.
Take care not to use 00H - CP/M function 6 does not return the ^@
key! Also codes really must be control codes - 01H to 1FH
otherwise the panels get funny, and results might not be what you
expect when editing a sector.
That's it Folks -
Willie Davidson
8 Comely Bank Street
Edinburgh
Scotland.
