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Amiga GIGA Graphic CDs 1-4 (1994)(Geuther)(Disc 3 of 4)[!].iso
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xprquickb.doc
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1994-03-30
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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* |_o_o|\\ Copyright (c) 1990 The Software Distillery. All Rights Reserved */
/* |. o.| || This program may not be distributed without the permission of */
/* | . | || the authors: BBS: (919) 382-8265 */
/* | o | || Dave Baker Alan Beale Jim Cooper */
/* | . |// Jay Denebeim Bruce Drake Gordon Keener */
/* ====== John Mainwaring Andy Mercier Jack Rouse */
/* John Toebes Mary Ellen Toebes Doug Walker Mike Whitcher */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
Trademarks
Amiga is a trademark of Commodore-Amiga, Inc.
A-Talk III is a trademark of Felsina Software.
Lattice is a trademark of Lattice, Inc.
Introduction
The XprQuickB shared library supports an external file transfer
protocol (XPR) for Amiga programs such as VLT and A-Talk III. It
supports the Quick B protocol developed and used by CompuServe
Incorporated as an enhancement of their B protocol. Generally,
Quick B protocol file transfers are significantly faster than
transfers with older protocols.
Credits
The protocol support code currently used in in xprquickb.library was
originally written by Russ Ranshaw of CompuServe. It was then rewritten
in C by Paul M. Resch (available as QUICKB.ARC in LIB 4 of the
AmigaTech forum on Compuserve). Jack Rouse modified it for Lattice C
5.04 and the XPR protocol. Some of the supporting code was inspired by
Rick Huebner's XPRZModem library, as was the option format. Willy
Langveld of the Stanford Linear Accelerator Center (SLAC) developed the
XPR interface.
Any bug reports for xprquickb.library should be directed to the
Software Distillery.
Use
To use the Quick B external protocol, you must have the file
"xprquickb.library", which should be in this library. This can be
copied to one of system directories used with your communications
program using the CLI command:
copy xprquickb.library LIBS:
You must also have a communications program supporting XPR external
protocols. Versions of VLT since 4.036 support the XPR protocol.
Versions of VLT since 4.226 support revision 2.0 of the XPR protocol,
allowing downloads to be automatically initiated. The current version
of A-Talk also supports XPR.
You must select "xprquickb.library" from the external protocol menu of
your communications program. At this point, QuickB transfers can be
initiated automatically (with communications program support) or
manually via menu selections. Various options are provided to control
the operation of XprQuickB. These are described later. The
communications program may allow ongoing transfers to be aborted.
File transfers are initiated by actions on the host system (CompuServe).
In general, file transfer will require an eight bit data connection.
XprQuickB will attempt to put the communications program in eight bit
mode.
The host sends a request to query file transfer capabilities and start
the file transfer. If the file transfer does not start automatically,
you can request the communication program to go into file transfer
mode. This causes an dialog mode to be started within XprQuickB. This
mode, provided for compatibility with older programs, is described in
the following paragraphs.
The dialog mode requires the "xpr_gets" call-back function to be
implemented. The communication program will ask for a file name. Once
the filename is entered, XprQuickB assumes a dialog must be initiated
with the host to start the transfer. XprQuickB will request the first
line of the dialog, with the prompt "Startup line?". The requester may
be seeded with the commands "dow/proto:qb" or "upl/proto:qb" which will
request CompuServe perform a file transfer. Cancel the request if no
first line is needed.
After the first line is sent, other interactions can occur with the
host. In particular, CompuServe will prompt for the file name on your
computer. XprQuickB transfers prompts (messages without line
terminators) as communication program requesters, seeded with the
previously entered file name. If no host output occurs for 10 seconds,
the transfer is aborted.
Options
The behavior of XprQuickB can be configured through the options
interface. The exact details of this interface depends on the
communications program, but the essentials are described below.
Consult the documentation of your communications program to determine
how to access these options.
XprQuickB supports both string oriented and requester oriented option
entry. The string interface can be used with older programs, and to
define default options when XprQuickB is loaded. The requester
interface is easier to use interactively.
The string option format corresponds to the format used with XprZMODEM.
The option string consists of a series of "words", separated by spaces
or commas. Case is ignored. The first character of each word
identifies the option. The second and following characters define the
option value. All of the options below except I/O buffer size use only
the first character of the option value.
The option descriptions below are headed by the option letter (in
parenthesis), followed by the option description used with the
requester interface. Subheadings on the following lines describe the
allowed option values.
(T) Text mode
Y
Turn text character editing on. On downloads, carriage
return and line feed pairs are turned into line feeds, the
standard Amiga line termination. Also, characters following
a control-Z are ignored. On uploads, carriage returns are
added before line feeds, which makes text more easily
portable to other machines.
N
Turns text character editing off. All characters are passed
through as untranslated binary.
C
Consult the communications program to determine the text/
binary status. XprQuickB defaults to binary transfer if the
communication program cannot assign a status,
H
Use the host's suggestion. For uploads, text or binary mode
must be specified on the host command. This is the default
value of the option.
(O) Overwrite mode
Y
Silently overwrite existing files during downloads.
N
Avoid overwriting existing files. This is done by
appending ".dup" or ".dupN" (for N a number from 2 to 99)
to the downloaded file name. The new name will generally
appear in the file transfer status window. If 99 ".dup"
files exist, ".dup99" will be overwritten. This is the
default value of the option.
S
This option aborts the download if the file exists.
(B) I/O buffer size (KB)
nnn
Here, "nnn" is a number representing the desired file buffer
size in multiples of 1024 bytes (KB). This allows the disk
to be accessed less frequently. A value of 0 disables file
buffering by XprQuickB. The default is 16 KB. The buffer
is allocated only during file transfers. If the buffer can
not be allocated, XprQuickB uses no buffering.
(A) Auto-activate transfers
Y
Setting this option on allows file transfers to be started
at the request of the host system. This is the default.
N
This disables host initiation of transfers.
(D) Delete after sending
Y
Turning this option on causes an uploaded file to be deleted
locally after a successful transfer. The communication
program must support the "xpr_unlink" call-back function to
enable this option.
N
Uploaded files are retained. This is the default.
(K) Keep partial files
Y
Setting this option on causes the incomplete file from an
unsuccessful download to be retained.
N
Setting this option off causes the incomplete file to be
deleted. The deletion occurs only if the "xpr_unlink"
call-back is supported. This is the default (if
"xpr_unlink" is available).
Compiling
XprQuickB was compiled with Lattice C 5.04. This simplifies the shared
library interface, avoiding stub routines. The supplied "LMKFile"
compiles and links the library. Note that the code must be compiled
with the "-ml" and "-v" options.