8-bit Software Disc Magazine (c) Duncan Webster 1991
Issue 13 June 1991
AMCOM to ADFS Transfer Program
Disc users will know that there are many versions of filing systems
around of both DFS and ADFS formats. Acorn, Watford and Opus are just
3 examples. Of all the companies that did produce their own filing
systems, the Amcom DFS is probably most remembered for it's
"notoriously non-standard" operation (to quote one national computer
magazine).
Dr Clarke, a new member of 8-bit Software, has kindly submitted this
utility to enable you to transfer software from Amcom DFS format to
the Acorn ADFS format discs with ease. All you need is your Amcom
format disc, and a blank formatted ADFS disc to hand. It might be a
good idea to backup your Amcom DFS files first to be on the safe side.
This utility is supplied by the kind permission of the author, and
should be maintained for your own use only. Please do not distribute
this software to any individual or medium without the express written
permission.
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INSTRUCTIONS for AMCOM to ADFS transfer Program ...
These programs transfer the files on one or more Amcom extended mode
discs to an ADFS disc. They require dual double-sided disc drive with
an ADFS/DFS supporting OSWORD &7F (ie. with 1770 or equivalent floppy
disc controller). Files are saved to two ADFS directories for each
side of each Amcom disc. At the start, the user defines a letter as
the first character of the directory name. If, for example this is
"A", then the first 32 files on the first side of the Amcom disc are
transferred to ADFS directory A0 with the remainder (if any) into
directory A1. Similarly, files on the second side of the Amcom disc
go to directories A2 and A3, and from the second Amcom disc to
directories A4 to A7 and so on. Files originally in directories other
than $ are put in equivalent ADFS sub-directories. Files locked on
the original disc are "read-only" on the ADFS disc. Files are saved
with their original load and execution addresses.
Since the Amcom DFS has its own non-standard rules relating to
filenames and directories, some editing of these may be necessary.
The program checkes filenames and if they are longer than 10
characters requests the user to input a new filename. The Amcom DFS
differentiates between upper and lower case letters in directory and
in filenames, so that two different Amcom filenames might be equated
by ADFS. This is checked for, and where necessary, the user is
invited to alter the filename or directory. (note that a directory
replacement must be one character length).
During transfer the Amcom directory and filename appears on the left
of the screen (and on printout if specified). On completion of
transfer of a file the ADFS directory, sub-directory (if any) and
filename appear to the right of the same line. Speed of transfer of
long files depends on the amount of memory available for files. This
is set by the first program according to the value of PAGE. At its
maximum, PAGE=&E00, there is 18k available, and files up to that
length are transferred in one step, longer files having to be split.
The first program "AMCOM" assembles machine-code routines and sets
parameters which are not altered by the main program "AMCOM2" - AMCOM2
can be run repeatedly. WARNING - When using Amcom discs on a machine
not fitted with Amcom DFS it is highly desirable to fit a write
protect tab.
ERROR MESSAGES:
"Not an Amcom Disc" (error &81)
The first bit of the disc is not set
"Cant Read Catalogue" (error &82)
Disc error on attempting to loan Amcom catalogue
"Illegal Filename" (error &83)
Character of ASCII value < &20 found in memory for filename. This
also traps discs created by 0.90 Acorn DFS.
A disc read error whilst transferring a file will abort transfer of
that file only with the message "not transferable" replacing the ADFS
description on the screen and printout.
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A complete breakdown how how the program was contructed & all
variables, locations and routines used is available to anyone upon
request.