ecctp@warwick.ac.uk (Dr J A K Cave) (09/12/89)
The following documents a utility that I received as shareware. Although
it bears a copyright notice, I believe it is available free. If this belief is
mistaken, please notify me. I shall wait a week before posting the code
(on c.b.i.p) to seek advice.
LPT2DSK - Capture printer output to disk file.
Version 1.0
October 3, 1986
(c) Copyright by George G. Bouche
This program works by intercepting the printer bios interupt (17h) and capturing
the would be printed data in a buffer which is later written to a disk file. By
capturing at the bios level, all dos printing (file redirection, Ctl-PrtSc, LPT?,
PRN, ...) and programs which call the bios directly (BASIC, Shft-PrtSc) are
handled. Capturing is for a specific printer (LPT1, LPT2 or LPT3) and output
to the other two printers is passed thru to the original INT17 interupt address.
Usage:
LPT2DSK [p] [nnK] [F=[d:][\path]filename[.ext]]
p=1, 2 or 3 printer number for LPT1, LPT2, or LPT3
Default=1 LPT1
nn=1 to 64 the amount of memory (in multiples of 1024 bytes) to
allocate to the printer buffer. The K is required.
Default=64K
filename any valid dos filename (can be a device) with
optional drive, path and/or extension. The F=
is required.
Default=LPT2DSK.p where p=printer number as above
on the current drive, current directory.
Requirements:
- Dos 2.0 or later.
- The parameters can be in any sequence but must be delimited by space(s).
- Any or all parameters can be ommitted.
- The environment must have an entry for locating COMMAND.COM (COMSPEC= )
and COMMAND.COM must be available as it will be loaded.
- LPT2DSK.EXE needs 9120 bytes + XXXX bytes for the resident portion of
COMMAND.COM(for dos 3.1 this is 3200) + buffer size.
- Multiple printers can be captured - just run the program again for the
other printer. Remember, last one started is the first one to exit from.
- Dos redirections of the printer (i.e. to COM?) are not detected and
no data will reach the buffer.
- The printer port hardware need not be present to capture data. The printer
status of the captured printer is returned as ready/not busy unless the
buffer has filled.
Examples:
LPT2DSK 2 32K F=CAPTURE.DAT
capture LPT2 and reserve a 32k buffer. a secondary
level of command.com is loaded. interupt 17h is
replaced; no hardware or dos interupts are disturbed.
... run the programs that print
and/or hit shift-print-screen
and/or hit control-print-screen
printing to LPT1 or LPT3 goes on un-affected
if the buffer gets full, dos returns an
"Not ready error writing device LPT2
Abort, Retry, or Ignore"
the only option is to abort.
EXIT exit secondary command.com and end LPT2DSK
the file CAPTURE.DAT is opened and data is written.
if the file existed before, it is overwritten.
if no data was printed, the file will not be opened.
interupt 17h is restored to value before capture.
all allocated memory is returned - nothing resident.
LPT2DSK F=LPT1 3
capture LPT3 and reserve a 64k buffer.
the buffer will be written to printer 1 when done.
Please direct any comments/suggestions/problems to:
George G. Bouche
P.O.Box 65111
Lubbock, TX 79464ecctp@warwick.ac.uk (Dr J A K Cave) (09/12/89)
Code will be posted in a week if no copyright problems surface. Please advise.
LPTx : Line Printer Output Capture Routine
------------------------------------------------------------------------
Version 6.00
(C) Copyright 1987 by Mark DiVecchio, All Rights Reserved
This program is released for use in non-commercial environments. I ask
commercial users to register the program with a $25 copyright fee for each
site (any number of users and computers) at which the program is used.
DISCLAMER : This program tries to perform a function which is not supported
by DOS. It will work sometime and will not work other times. That kind of
explains why you don't see this type of program on the market. I have
tested it under DOS 2.x and 3.x. In particular, under 3.x, I used dBase-II.
I have not tested it with dBase-III or dBase-III+.
Mark C. DiVecchio
10435 Mountain Glen Terrace
San Diego, CA 92131
619-566-6810
------------------------------------------------------------------------
First - some thanks... I would like to thank all of the users who
have called me about the earlier versions of LPTx which has been floating
around for about a year. The program has met with mixed success. There
seems to be no pattern as to when the program works and when it doesn't. I
am still searching for the solution to this very difficult problem. This
version and versions 4.x and 5.x which preceeded it are attempts to perform
the same function with a different algorithm. Version 3.00, 4.00, 5.00 and
6.00 are not replacements or upgrades of each other but just alternative
implementations.
------------------------------------------------------------------------
Have you ever wanted to get some data from your screen into a
program? Have you ever wanted to grab onto some printer data and put it
into a disk file but the program you are using does not have that as a
option? Well here is the answer to your problem. This program will grab
onto anything sent out of a line printer port as long as the program uses
the standard BIOS INT 17h call. This version works with Shift-PrtSc or
Ctrl-PrtSc but does not work with the DOS TYPE command.
This program intercepts the BIOS interrupt 17h, the line printer
interrupt. It will redirect the output of LPT1, LPT2, or LPT3 to a disk
file. All three redirections may be active at the same time.
This version of LPTx counts on the PC having some "free time" in
order to write the data to disk. The program gathers data into a large
buffer and during timer interrupts and keyboard idle periods, it writes it
to disk. DOS must not be in its critical section for the write to take
place. LPTx does not work with the DOS TYPE apparently because the critical
section flag is always set when the timer interrupts occur. It should work
with most user programs since the critical section flag is not set in user
programs and therefore will not be set when timer interrupts occur.
Look at the Assembly Language Source which you should have received
with this documentation file. If you would like the other versions of LPTx,
I will be happy to send them to you. Just send me a formatted 360K DSDD
floppy (no DOS on diskette) along with a post-paid, self-addressed floppy
mailer. I will send you all current versions that are active. If you
received this disk directly from me, all of the different versions are
already on the diskette.
LPTx requires DOS 2.0 or later. It has been tested on version 3.1
of DOS as well.
Calling sequence:
lptx [?] [-x] [-l] [-i] {-1,-2,-3} {-c -o <d:[pathname]filename>}
where -1 means redirect LPT1, -2 means redirect LPT2, -3 means redirect
LPT3
This option must appear first
-o means start the redirection to file specified. If redirection
is already in progress for the selected line printer,
the old file will be closed first.
(If you do not specify -o but you do specify a line printer,
LPTx will use either the last file name that you gave when
you loaded LPTx or will use the file named LPTXy.LST which it
will create in the root directory on the default drive - where
y is 1, 2, or 3.)
It is not necessary that you specify the complete path name
for the file. LPTx will create the file in the default
directory if you don't specify a directory. LPTx will always
be able to find the file because it saves the complete path.
-c means close the file and send all further output directly to the
line printer.
If neither the -o or the -c option is specified, LPTx just displays
the program status.
-? displays a short help screen.
-x tells LPTx to ignore the DOS Critical Section Flag. Use this
option only with great care. LPTx may do unusual things if the
flag is ignored.
-l tells LPTx to strip linefeed characters from the data as it is
being redirected.
-i removes LPTx from the interrupt chain. This effectively inactivates
the program. The memory which it occupies is not freed.
note: -1, -2, and -3 are mutually exclusive
-o and -c are mutually exclusive
examples:
lptx Displays the program status
lptx ? Displays a HELP screen
lptx -1 redirects LPT1 output to file named
LPTX1.LST in the root directory
on the default drive or the last
named file.
lptx -o a:\able.xxx redirects LPT1 output to file named
or a:\able.xxx. Any open redirection
lptx a:\able.xxx disk file for LPT1 is closed.
lptx -2 b:xx.lst redirects LPT2 output to file named
XX.LST in the default directory
on drive B:. Any open redirection
disk file for LPT2 is closed.
lptx -3 d:\ab\cd\file.lst redirects LPT3 output to the file named
file.lst in the directory ab\cd on drive
d:.
lptx -c closes any disk files open for LPT1 and sends
or the output back to the line printer
lptx -1 -c If no redirection is taking place to LPT1,
this is a NOP. LPT2 and LPT3 are not
affected.
lptx -2 -c closes any disk file open for LPT2 and
sends the output back to line printer.
if no redirection is taking place to LPT2,
this is a NOP. LPT1 and LPT3 are not
affected.
By redirecting LPT2 or LPT3 to a disk file, you can in effect have
2 or 3 printers on your system. LPT1 can be your physical printer and you
can have LPT2 output going to disk. When you redirect LPT2 or LPT3, LPT1
works normally.
If you are redirecting to a diskette file, do not remove the
diskette once the redirection starts. I recommend redirecting to a hard
disk or a RAM disk.
If LPTx encounters any kind of error during the redirection, it
terminates operation and sends output back to the line printer. It does not
display anything but beeps the speaker. Four beeps indicates a DOS disk
access error. Two beeps indicates an internal buffer overflow error. This
prevents your currently running program from possibly getting destroyed. An
error with LPT1 redirection does not shut down LPT2 or LPT3 redirection.
LPTx captures the int 17h interrupt vector. Problems may occur with
print spoolers which also take over the int 17h vector. You can be sure
that LPTx works correctly by running LPTx before you run your print
spooler. LPTx will be transparent to the print spooler but your print
spooler may not be transparent to LPTx. LPTx works fine with IBM's PRINT
command.
LPTx also captures the int 24h critical error interrupt vector.
This is done only for the period that LPTx is using the disk. This prevents
the generation of funny error messages in the middle of other programs that
you may be running. (LPTx just beeps 4 times and clears itself out of way
if a disk error occurs).
This version of LPTx can redirect all three printers to three
different files with all 3 active at the same time.
LPTx worked correctly when I tested it with:
1. dBaseII,
2. the ARC utility with the "p" option and output redirected to prn,
3. shift PrtSc,
4. DOS PRINT utility,
5. Lotus 123,
6. dir > prn,
LPTx did not work with:
1. The DOS TYPE command,
2.
Version 6.00 of LPTx uses about 20K of memory for the resident data
buffers and interrupt handler. This is greater than the previous versions
of LPTx because I made the disk buffers larger.
If you modify or find any bugs in this program, I would appreciate
it if you would drop me a line with the changes. Use the address above.
Updates and new versions of this program can be found on the RBBS
at 619-741-3412.ecctp@warwick.ac.uk (Dr J A K Cave) (09/12/89)
Code will be posted in a week if no copyright problems surface. Please
advise.
PRNDSK Version 1.00
A Printer-To-Disk Redirector
INTRODUCTION
------------
PRNDSK is a utility that redirects output intended for a printer
or communications port and sends it to a disk file or other
device. It is intended to make it easy to capture disk copies of
printed output and screen dumps. It can also be used to discard
printer output by redirecting it to the NUL device, and you can
even use disk files as "virtual printers" if your computer does
not have the printer ports you need.
PRNDSK is written for the IBM PC and closely compatible
computers, running MS-DOS version 2.00 or later. Although it
tries hard to be reliable, it is very likely that there are
computers and programs with which it will not work. If you have
problems, or suggestions for improvements, contact the author:
David H. Rifkind
3993 N. Campbell Ave., #53
Tucson, Arizona 85719
BIXMail: drifkind
PRNDSK and this document are copyright 1987.
SYNOPSIS
--------
There are three basic formats for the PRNDSK command:
1. PRNDSK [/C][/F]
Displays information about devices currently being
redirected, or closes all files (/C), or flushes them
to disk (/F) while leaving them open.
2. PRNDSK device [/C][/F][/N][/T]
Displays redirection information about the specified
device, or closes its redirection file (/C), flushes it
to disk (/F), or sets or clears the transparency mode
(/N, /T).
3. PRNDSK device=filespec [/A][/T]
Begins redirecting a device to the file specified. The
/A switch is used to append to an already existing
file, and /T to set the transparent redirection mode.
"Device" may be one of the following names:
LPT1 through LPT3 Printer ports 1 to 3
COM1 or COM2 Serial ports 1 and 2
PRN Same as LPT1
AUX Same as COM1
"Filespec" may be any unambiguous file specification. Legal
examples include:
PRINTER.TXT
A:COM1.TXT
..\LISTING
C:\DEVEL\PRINTER.TXT
NUL
REDIRECTING OUTPUT
----------- ------
To direct output intended for a printer or serial port to a file,
enter the following command:
PRNDSK device=filespec
"Device" should be replaced by the name of an output device:
LPT1, LPT2, LPT3, COM1, COM2, PRN or AUX. "Filespec" is replaced
by the name of a file to receive the output. Here is an example
of a legal command:
PRNDSK PRN=PRINTER.TXT
This will result in output to the printer being sent instead to
the file PRINTER.TXT in the current drive and directory. A drive
and path name may also be included in the filespec:
PRNDSK COM1=C:\FILES\LOGFILE.COM
In fact, "filespec" may be any MS-DOS file or device name,
including CON, NUL, or even a printer or serial port! If output
is redirected to a serial port or printer port, it is not further
redirected. To make this clear (or at least clearer):
PRNDSK PRN=COM1
PRNDSK COM1=COMM.TXT
In this example, output sent to the PRN device will go to serial
port number 1; it will NOT go to the file COMM.TXT.
There are two switches which may be included with this form of
the PRNDSK command. The /A switch:
PRNDSK device=filespec/A
causes data to be appended to the output file. If the /A switch
is not included, the file will be erased before beginning output.
The /T switch:
PRNDSK device=filespec/T
results in transparent output--characters output will go to both
the redirection file AND to the specified device. This allows
you to make both a soft and a hard copy at the same time.
Once redirection to a file is begun, the disk containing that
file should not be removed. Close the file (see OUTPUT CONTROL)
first.
OUTPUT CONTROL
------ -------
To close an output file and terminate redirection for that
device, use this command:
PRNDSK device/C
or PRNDSK/C
The second version closes all files and terminates all
redirection.
PRNDSK also lets you flush an output file, that is, update the
file directory information on the disk without closing it. Make
whatever use of this that you can:
PRNDSK device/F
or PRNDSK/F
DEVICE STATUS
------ ------
To keep track of what devices you have redirected, PRNDSK will
show you the status of each device it handles. To find out to
what file a given device is being directed, enter:
PRNDSK device
For example:
PRNDSK PRN
The reply might be:
LPT1=C:\FILES\PRINTER.TXT
If the device is set for transparent redirection, the file name
will be followed by a "/T":
LPT1=C:\FILES\PRINTER.TXT/T
If redirection to the file has been stopped due to a DOS error,
the error message will be shown after the file name:
LPT1=C:\NONESUCH\PRINTER.TXT
Path not found
Finally, if the device in question is not being redirected, there
will be no reply. To list all devices being redirected, type:
PRNDSK
Note: the way the filename is reported varies slightly with
different versions of MS-DOS. In DOS 2.xx, the filename is
reported exactly as you entered it. In DOS 3.xx, the complete
unambiguous filespec is given.
PRNDSK PRN=..\FILES\PRINTER.TXT
DOS 2.xx: LPT1=..\FILES\PRINTER.TXT
DOS 3.xx: LPT1=C:\SUBDIR\FILES\PRINTER.TXT
CHANGING MODES
-------- -----
A redirected device may be switched into and out of the
transparent mode using one of the following commands:
PRNDSK device/T to set transparent mode
PRNDSK device/N to clear transparent mode
"/N" is a mnemonic for "not transparent", and deserves an award
as one of the least mnemonic mnemonics ever.
ERROR HANDLING
----- --------
If any DOS error occurs while PRNDSK is trying to write to a
file, the associated device will become "inactive". Attempts to
write to the device will generate printer I/O errors (for the
printer ports) or timeout errors (for the serial ports). The
device will remain inactive until it is closed (by PRNDSK/C).
COMPATIBILITY
-------------
PRNDSK intercepts the IBM PC's BIOS INT 14h and INT 17h vectors
(the serial and printer service interrupts). It may not work
correctly with other programs which also take over those vectors.
In most cases, PRNDSK will work with printer buffer software if
it is loaded AFTER that software. Due to the design of the IBM
PC's ROM BIOS, a great number of programs that use the serial
ports will not work with PRNDSK. However, if your serial ports
are being used for simple output devices such as printers or
plotters, it should work. Don't be surprised, though, if your
modem attached to COM2 prevents your using PRNDSK with the
printer attached to COM1.
PECULIARITIES
-------------
"Peculiarity" is the word we have chosen to describe some of the
stranger aspects of PRNDSK's operation. The word "feature" might
also be used. Use of the term "bug" is frowned upon.
In order to work correctly with DOS, PRNDSK keeps track of calls
to the various DOS services. This allows it to decide when it is
safe to write to the disk, and when to wait for a better time.
It is not always possible to make this decision correctly, so
PRNDSK adopts a conservative approach: it never writes to the
disk unless it is quite sure that it is safe.
Under some circumstances, it may be impossible to write to the
disk for a considerable period of time. When this happens,
PRNDSK can lose some characters which were sent to the printer.
This is rare, and may happen with some programs and not with
others. One simple example which will demonstrate this is:
COPY somefile PRN
where "somefile" is more than about 2K bytes long. There is no
apparent good solution for this problem.
Another peculiarity has to do with opening files. Under some
circumstances, this sequence of commands:
CHDIR \FIRST
PRNDSK PRN=PRINTER.TXT
CHDIR \SECOND
will result in PRINTER.TXT appearing in directory SECOND instead
of FIRST. This will happen only (1) when using DOS 2.xx and (2)
the first time that PRNDSK is run (that is, if PRNDSK is already
resident in memory, this will not happen).
If this behavior causes a problem, you can follow the first
PRNDSK command with:
PRNDSK PRN/F
which will ensure that the file ends up in the correct directory.
PROGRAM NOTES
------- -----
This is the first publicly released version of PRNDSK. There are
other programs that do about the same thing. I hope that PRNDSK
is more reliable and more functional than the others. I also
hope that you find it useful.
This first version is fairly rough in several ways. Since it
uses a 2K buffer for each of five devices, over 8K of memory is
wasted if only one is being redirected. There are also all those
darned "peculiarities" (see above). If there is enough interest
in PRNDSK, I might get ambitious and make improvements.
This is copyrighted material. No fee is charged for its use.
You may reproduce and distribute it as you see fit, but please do
not distribute modified or incomplete copies.
28 Feb 1987root@cca.ucsf.edu (Systems Staff) (09/13/89)
In article <238@orchid.warwick.ac.uk>, ecctp@warwick.ac.uk (Dr J A K Cave) writes: > Code will be posted in a week if no copyright problems surface. Please > advise. > ... > > This is copyrighted material. No fee is charged for its use. > You may reproduce and distribute it as you see fit, but please do > not distribute modified or incomplete copies. In this case the release is explicit so the only question is its authenticity. But the announcement at the beginning is a bit disturbing. Even though its author may understand correctly, the way it is expressed may be misleading to some. If there is doubt about the status of the material it is the responsibility of the person proposing to distribute it to obtain explicit permission from the copyright holder. It is not enough to make a statement of your intentions, even publicly, and take silence as permission. Whether you could make such an assumption if you had directly notified the copyright holder is a question that only legal counsel could advise you on and the question probably has many complicating factors. Thos Sumner Internet: thos@cca.ucsf.edu (The I.G.) UUCP: ...ucbvax!ucsfcgl!cca.ucsf!thos BITNET: thos@ucsfcca U.S. Mail: Thos Sumner, Computer Center, Rm U-76, UCSF San Francisco, CA 94143-0704 USA In assumption lies litigation. #include <disclaimer.std>
ecctp@warwick.ac.uk (Dr J A K Cave) (09/13/89)
Thanks to all for advice re: posting other folk's code. It would take a while for postings to make it through the backlog on c.b.i.p. anyhow, so I won't bother. I guess the best thing to do is contact the authors listed in the documentation. It's a bit hard for me, being overseas and all. Sorry to raise anyone's hopes unnecessarily. A couple of hints, though: 1) there is an LPT utility included free with Harvard Graphics; 2) any program run within MS Windows can be ported to a file by declaring the file to be an output port in WIN.INI. This will work with e.g. 123 if you declare a postscript printer when setting up and redefine LPT1 before using PrintGraph. 3) there is one MAJOR drawback that might not be evident if you've only used hardpronter connections before; the PS files tend to be on the immense side (like 3-700K for a single graph), so I hope you have lots of storage space, lots of patience, and/or a good background upload/print program. Once again, sorry for the blundering. Next time I'll know better.