8bitfiles.net/archives/archives.tar/archives/genie-commodore-file-library/C128CPM/PMAUTOAE.COM/ADDENDUM.DOC

Text File | 1979-11-30 | 5.7 KB | 116 lines

Extra information on the usage of the PMArchive Suite of software

In addition to the commands and options that can be gleaned from the
previous DOCs and usage summaries there are some VERY useful ones that
were missed.

Firstly the PMARC & PMEXT programs both work on multiple files ie If
wild-cards are used in PMEXT then it will search ALL matching Archives
not just the first match it finds which I find very useful when you
set up one disk with many archives each dealing with one program
group.

Also with PMEXT more devices are supported than has yet been revealed!
with the usage:-
PMEXT [D:]<filename><extension> {device:}<filematch>(options)
where all parameters are optional.
both D: and device: will use default drives if they are left out.
In addition though the {device:} option can redirect file output to
other devices:-
A: - P: to drives as usual
LST: outputs to current list device (printer etc:) and if the /P
option is used form feeds will be sent at the PMSET intervals.
PUN: outputs to the CPM2.2 Paper Punch device or whatever is driven by
that BIOS function with as far as I know no re-formating of the passed
data.
CON: outputs to the console and if the /P(aginate) option is used the
there are a few quite unique functions that can be invoked by keyboard
input.
After a screen full of text you can press Enter/Return A, B, Q, X or
Space.
Each performs a specific function and are read from the console
buffer.
Enter/Return - clears the screen and displays the next screen-full.
A - Aborts this file listing.
B - Goes Back one Page. (can only go back as far as the first page in
current block)
Q - Quits the Read function and exits to CCP prompt.
X - Displays one line at a time.
Space - Displays the next screen-full without clearing the screen.

An example command line could look like this:-
A> PMEXT B:* CON:*.DOC/I/P

Which would load PMEXT from drive A, and search drive B for all files
that matched ????????.PMA and when it finds one it searches the
directory for a DOC file and dosn't display non-matches when it finds
one it will extract it to the console with pagination and you can then
use the above keys to view the DOC. If you abort with A key or reach
the end of text and press Enter the search for the next DOC file
resumes, and the process continues until either the last archive has
been searched or the search is aborted by the Q key during reading.
I personaly find this to be a very good text viewer in its own right.

EXE: Will decompress the given .COM file into TPA and execute it in
much the same way as the LRUN.COM utility does for the .LBR format and
a command line can be passed to the file in the normal cpm way.

A short note on the compression ratios that I have achieved and
compared against various Archivers for both CPM and MS-DOS and also
stand-alone compressors.

Firstly this may be difficult to believe but PMARC beats the ms-dos LHA
archiver which, so I gather is were the inspiration for PMARC came
from. It also beats the ms-dos ARC format archiver and PKZIP1xx though
I don't think it beats the new version 2 alogarithms.
Obviosly it beats the CPM ARK archiver hands down on both compression
and facilities and does all that the .LBR format can with just the two
main PMARC & PMEXT files. It beats all the stand-alone compressors
including CRLZH20.COM which as far as I know was previosly the best
one for CPM.
There is only one existing archiver that I know of that beats the PMA
alogarithms for sure and that is MS-DOSs ARJ archiver though it's not
by much! with an XRS mail packet which consists of a number of
different files the ratios achieved only differed on average by 2.5%
in favor of ARJ which considering the speed of extraction with UNARJ
and that of the PMEXT that small diference in ratios definately shows
that the whole suite is very well coded and alot of thought went into
its design.

I downloaded this suite in two parts from aspects BBS manchester and
decided to repack them in the one selfextracting COM file in order to
make it easier to transport the whole package! If you are reading this
from the original format then obviously it'll work on your system if
you received this as an ARK or LBR it wasn't my doing and you'll have
to test and make sure that you're using a Z80 or better based machine
with at least as much TPA as shown in the command Sumaries header.

If you wish to pass this on to anyone PLEASE keep it in this
self-extracting form as it is the smallest form that has the widest
compatability with most CPM machines.
It can be treated just like any other PMA archive and files can be
added to it if they are considered nesesary.

The biggest flaw with this suite is that it does not support du:
specifiers. I suppose that some of those who realy nead them could
possibly hack a fix but if they do then it'd be a good idea to change
the z80 specific instruction DJNZ dis. used throughout this suite to:
DEC B
JR NZ,dis
which would then make it usable on old 8080 systems and on the V20
series in 8080 mode.

Note the High speed mode option in PMARC may be faster but it
definately reduces the amount of compression obtained.
Also when creating a PMEXE type archive remember that there must be
enough TPA to allow both the existing archive and the expanded form to
exist in otherwise it will jam up!

At this moment in time there is no ms-dos method of extracting PMA
type archives. The closest thing they have is the LZH archive and
although PMEXT will extract files from those the oposite will not work
yet, maybe they'll catch up one day. <grin>

PMAUTOAE.COM with this DOC was compiled by Johnathan Taylor 06/02/93