home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Precision Software Appli…tions Silver Collection 4
/
Precision Software Applications Silver Collection Volume 4 (1993).iso
/
new
/
showgif.arj
/
SHOWGIF.DOC
< prev
next >
Wrap
Text File
|
1993-04-05
|
54KB
|
1,322 lines
┌─────────────┐ ┌────────┐┌───────────┐
│ ┌─────────┐ │ │ ┌──────┘└┐ ┌─┐ ┌────┘
│ │ │ │ │ │ │ │ │ │
│ └────────┐│ └────┐┌─────┐┌─┐ ┌─┐│ │ │ │ │ └──┐
└────────┐ ││ ┌──┐ ││ ┌─┐ ││ │┌─┐│ ││ │ ┌────┐ │ │ │ ┌──┘
│ ││ │ │ ││ │ │ ││ ││ ││ ││ │ └──┐ │ │ │ │ │
┌────────┘ ││ │ │ ││ └─┘ ││ └┘ └┘ ││ └────┘ │┌┘ └┐│ │
└──────────┘└─┘ └─┘└─────┘└───────┘└────────┘└───┘└─┘
Version 5.5
Written by
Bill Parquet
Features:
- Ability to view .GIF files while they're being
uploaded and downloaded.
- Easy to use interactive viewer.
- Very fast decoder, 20% faster than VPIC on certain
pictures.
- Hardware handshaking for use with high speed modems.
- Automatic detection and utilization of your machines
high memory.
- Password protection to keep out prying eyes.
- Intelligent screen saver, saves exact screen size &
character set
- Easy to use installation program with complete online
documentation.
Page 1
Introduction
─────────────────────────────────────────────────────────────
How often have you downloaded a GIF file from your
favorite BBS only to discover you wasted maybe 15 minutes and
150,000 bytes of download credit on an array of dots that
doesn't deserve to be called a picture, or had a "bad code in
file" after the first 10 lines? Wouldn't it be better to see
the picture as you are getting it? Just abort the transfer,
saving your time and credits for something more worthwhile if
you don't like it? If so, SHOWGIF is just the program for
you! It is a TSR that quietly waits for the system to begin
writing a GIF file. Once writing begins, SHOWGIF switches to
the appropriate VGA or EGA video mode, and shows the picture
as it is coming over. Unlike other view it while you get it
setups, it works with nearly ALL protocols available.
System Requirements
For SHOWGIF to operate properly, your system must be
equipped with an EGA, VGA, or Super-VGA video card. It also
requires about 32k of memory (mostly for GIF decoding).
Configuring ShowGIF
─────────────────────────────────────────────────────────────
Configuring ShowGIF is a very simple process. After
you've extracted the ShowGIF archive, simply run CSHOWGIF.
Each option in the CSHOWGIF has extensive online help in case
you have any doubt about what it does.
If you do not use a VESA driver or don't have these
capabilities built into your card's BIOS, you will have to
configure ShowGIF to use your video card. The easiest way to
perform this is to use the autodetect option in the mode
setup menu. Autodetect will try to determine what type of
video card you are using. After it is finished testing, it
will display a dialog box requesting that you check the mode
setup to make sure that the information it came up with is
indeed correct. Autodetect should not take more than 2
seconds to perform. If the screen remains inactive for
longer than that, then it is likely that the autodetect
process has somehow upset your card. If this is the case,
reboot your computer and perform the manual configuration
described below.
Page 2
Even if the autodetect worked perfectly, you should go
into the manual configuration menus to make sure the
information is correct. The next menu item below autodetect
is the card setup. You should perform this option first
before setting up the actual modes. In the card menu you
will be asked what type of card you have. First hit the TAB
key until you are over to the leftmost window. Select the
name of the chipset which your card is using. One of the
names should look somewhat familiar. If your card's chipset
is not on the list you have three options. The first is to
try each of the sets in hopes what one of them will be
similar enough to your card. Second, (if your cards less
than a year old) go through your drivers disks and try to
find a VESA driver. Third is just to give up and set up your
card as standard VGA. Due the similarity between most of the
cards, it may be likely that your exact card doesn't appear
on that list. If it doesn't just select any card (Even on
the menus with two or three cards, most of them perform the
same function) Finally, go to the box on the right and pick
out the amount of memory installed on your board. If you
have a standard VGA board, your installed memory is 256K.
SuperVGA boards may have anywhere from 256K to 1024K
installed. You will have to check your setup to determine
this. Memory sizes below 256K only occur on older EGA class
boards (most EGA boards have 256K).
After you've selected your card, chipset and memory
size, hit enter and go into the mode setup menu. All of the
modes will be listed in order from least to most resolution,
VGA modes before EGA modes. To test any mode, simply hit TAB
until the cursor appears in the resolution list box, and move
up or down until you've highlighted the mode you wish to test
and press the 'T' key. The screen should switch into that
mode and a series of lines should appear. You can stop the
test by pressing any key (the mouse is not responsive on this
screen). If a mode has failed you can either press enter to
edit the mode or press 'D' to delete the mode. If your
confident that your card can perform the mode, use the edit
option. If the mode cannot be displayed due to a
configurization error or if your monitor cannot handle that
resolution, use the delete option. If you find a mode which
ShowGIF forgot, you may add it any time by pressing the 'A'
key. The configurization program will automatically put the
mode in the right place, so you don't have to worry about the
position of the cursor. Once you are satisfied with the
setup, press the TAB key to move to the ok button and press
enter.
Editing and inserting modes is a fairly complicated
process. For this, you will get a dialog box asking all the
questions necessary for ShowGIF to utilize the mode. The
"Memory" box describes how the memory is mapped in that
particular mode. The selections are fairly obvious, select
EGA for 16 color modes, VGA for 256 color modes. X13 is
Page 3
reserved for 360x480x256 "tweaked" VGA mode available on some
cards.
Color depth is more dependant on your board than the
mode itself. For VGA boards, all modes (even EGA 16 color
modes) should use the VGA 6 bit DAC selection. EGA boards
should always use the EGA 2 big DAC.
Width, Height, and are fairly self-explanatory. Width
is the number of pixel columns on the screen. For 640x480,
the 640 would go in this input box. The height is the number
of rows on the screen. For 640x480, the 480 would go hear.
The colors prompt expects the total number of colors
displayable on the screen in that particular mode.
The AX, BX, CX, and DX fields will be the most difficult
to set up. You will have to look in your manual to make sure
the numbers here match those for your card. If your manual
only lists one number, it goes and AX and the rest of the
'X's are zero. Almost no cards have values in the CX and DX
registers. Keep in mind that this expects the numbers in
decimal (base ten) and most manuals list the mode numbers in
hexidecimal (base 16). If your manual does this, you will
have to convert the numbers by hand. Hopefully either the
autoconfiguration or card selection will take care of these
for you.
After you've set up your video card, you'll want to set
the other options for ShowGIF. These options can be found in
the options setup menu. The first line on this menu will
bring up the detection modes menu. This dialog box will
allow you to specify the default values for upload and
download stream and extension detection. Stream and
Extension detection will be discussed more thoroughly later.
The next option brings up the memory usage dialog. In
most cases you'll want to select the default memory model.
You would want to select "large model always" if you are
really conscientious about speed. Select "small model
always" if your library of pictures consists of many
"cartoon" type pictures (i.e. Large single color areas
instead of smooth color transitions) "cartoon" type pictures
generally refer to hand drawn pictures where normal pictures
refer to scanned pictures. If in doubt, use the help command
or just select the default memory model and ShowGIF will pick
out whichever it feels is appropriate.
The next option summons the "display options" menu.
This menu is a catch all of sorts for all of the options that
don't appear on any of the other menus. "Show GIF sizes"
determines if the sizes of the pictures should be show on
startup or just the filenames. If pause after display is
set, there will be a pause after the viewing is complete in
TSR mode (i.e. after the upload or download is complete).
Page 4
This option does not affect the interactive viewer. In most
cases, you'll want this option off. The delay field is used
to set the delay which the result is shown on the screen
after the upload/download is complete (or if an error
occurred). The password field is used to create a password
which must be entered whenever a picture is viewed. The
registration code removes the "Unregistered" message during
viewing and places your name on the viewing screen. When you
register your copy of ShowGIF, you will be given a code to
put in here.
Setting the keys is the most difficult part of the
setup. With the mouse, point to the "Abort display" or
"Blank Screen" text, click the mouse button then press the
key. With the keyboard, Press either Alt-A, Alt-B, or TAB to
highlight the name. Press Space, then press the key you wish
to use. The name of the key should appear.
The final option under that menu entry allows you to set
up the default directories to be used by ShowGIF for the
change directory command, move and copy. If you just plan to
use ShowGIF for online viewing, you do not need to set up any
directories. If you want to use ShowGIF's interactive
viewer, its a good idea to put your .GIF directories in the
list.
The last entry on the top menu brings up the entire
online documentation. The online documentation is very
similar to this documentation, only pages are connected using
hypertext links instead of sequentially.
Once you are finished, you can use the File | Save
changes to make your changes perminate. If you really mess
up and want to change everything back, a revert option has
been provided. If you don't want to save your changes, you
can use the "Quit" option or just hit Alt-X at any time.
Operation
─────────────────────────────────────────────────────────────
Once you have ShowGIF fully configured, the interactive
viewer may be started by typing SHOWGIF at the dos command
line. The TSR viewer is installed by using the /r switch, so
before you load your terminal program you would type "SHOWGIF
/R". ShowGIF will show an opening screen and go resident.
ShowGIF will sit dormant in memory until you begin a transfer
involving a .GIF file (using your existing protocols).
ShowGIF will probably not start displaying instantly after
the transfer begins, as it has to wait until enough
information has been received to start decoding. The length
of time you have to wait depends on your terminal program and
which protocol you are using. If your terminal writes data
immediately after it receives it, ShowGIF will usually start
Page 5
displaying after the first Zmodem block or after the fourth
Xmodem block. If your terminal is using buffered I/O in
order to reduce the amount of time spend in disk accesses, it
will take considerably longer. After the transfer is
complete ShowGIF will finish with either of three messages
depending on the result. These messages are "View
Successful," "Bad code found" and "View Aborted". After
you've logged off and quit your terminal program, you can
remove ShowGIF from memory by using the "/u" switch.
The first and last steps can be performed automatically
if you set up a batch file to load your terminal program.
Here is the batch file which I use to start ShowGIF and then
my terminal program
@ECHO OFF
C:
CD\QMODEM
SHOWGIF /R
TAG
QMODEM
TAG U
SHOWGIF /U
The first three lines are standard DOS commands. The
fourth line loads ShowGIF. The fifth line loads a different
TSR. The next line loads the terminal program. After Qmodem
is complete, the other TSR is unloaded, followed by ShowGIF.
You should note that the TSR's are removed from memory in the
opposite order in which they were loaded. If you use a TSR
control utility such as TSRCOM (Mark and Release) or POPDROP,
you do not have to worry about the load order.
Interactive Viewer
─────────────────────────────────────────────────────────────
If you don't specify any arguments when loading ShowGIF,
you will get the interactive viewer. The interactive viewer
allows you to view pictures one by one in a particular
directory, move the pictures around, copy, and erase them
without quitting ShowGIF.
The interactive portion of ShowGIF works in a similar
manner to the other .GIF viewers. To view any particular
picture, simply use the cursor keys to move to the file and,
once its highlighted, press enter to view the picture. You
can also use the alphabet and number keys to instantly jump
the next filename beginning with that letter. If you want to
view several pictures at once (similar to a slideshow) just
highlight each of their names by pressing space and then
press enter. The pictures will be viewed one by one with a 3
second delay between displays.
Page 6
If you see a picture that you really don't like, you can
erase it by moving the cursor on top of the name and pressing
ALT-X. You will be given an "are you sure" prompt, to make
sure you want to go through with the erasure. If you erase
the last file in the directory, ShowGIF will quit.
For safety purposes, Erase will only delete one file at a
time. If you have several files highlighted using the space
bar, erase will still only delete the file underneath the
cursor.
Changing directories is performed by pressing ALT-C.
You will be given a list box containing all of the default
directories which you set up in your configurization and an
"other" directory at the very end which allows you to enter
another directory not on the list. Move the cursor to the
directory you want to enter (or "other") and press enter. If
you selected other, you will be prompted for the directory
name (don't put a '\' backslash at the end).
Moving and copying file is performed in a manner similar
to changing directories. If you want to move or copy a
single file, move the cursor on top of the file and press
ALT-M for move or ALT-C for copy. You will then be given the
same prompt as change directory. The files will be moved or
copied into the directory you specified. Keep in mind that
move is the same copy except the files are erased after the
procedure is complete. If during either procedure the copy
should fail then the process will stop. In the case of move,
the file which caused the process to fail will not be erased.
ShowGIF Function Keys
─────────────────────────────────────────────────────────────
When active, ShowGIF allows you to perform two
functions. (This includes both immediate mode and during
file transfers) The first function is "Abort-View" It aborts
the ShowGIF file viewer, but not the transfer itself. I
don't see any practical use for this other than in immediate
mode when you've "seen enough of the picture." During a
download, if you abort the terminal's transfer using ESC,
Ctrl-Break or whatever, ShowGIF will automatically abort
along with the driver. Keep in mind that the abort view will
not abort the view immediately. Viewing will terminate as
the next block of data goes to disk.
The second function is an "on-demand" screen blanker.
Its there to prevent those particularly embarrassing moments
when your spouse walks into the room and happens to notice
that you are downloading that new X-Rated picture. Despite
that there is nothing on the screen, the download and view
will progress normally. Any subsequent keypress will unblank
the screen. The screen will automatically un-blank when
Page 7
ShowGIF finishes (i.e. at end of transfer or if an error
occurs).
The default settings are backspace for abort view and
tab for blank screen. You may change these with CSHOWGIF.
Note that, Shift/Ctrl/Alt shift key combinations are NOT
recognized! (i.e. Shift-X, Alt-X, Ctrl-X, and X are all the
same). ALSO NOTE: do not choose combinations that your
protocol uses for its functions. For example, if you're
protocol uses Ctrl-C to abort the transfer, don't set blank-
screen to C.
How ShowGIF Works
─────────────────────────────────────────────────────────────
Many of the worries associated with the operation of
ShowGIF stem from a lack of understanding about ShowGIF's
means of operation. If you are completely confident with
ShowGIF, you can skip this section, however if you are
concerned that ShowGIF will affect the reliability of your
transfer, I highly recommend reading the section.
General Description
DOS contains several services which allow applications
(such as your terminal program) for opening, closing, writing
to, and reading from files. ShowGIF positions itself between
the application program (usually your terminal program or
external protocol) and the DOS. In this position it
intercepts calls to DOS, checks to see if they are of any
importance to itself, then passes them along to DOS
unaltered. This sounds dangerous and destructive but, in
this situation, it is beneficial.
ShowGIF can be in one of two states when it intercepts
these DOS calls. The first state is where it monitors all
the open and write calls. If one of these calls implies that
a GIF file is going to disk, ShowGIF makes note of this file
and switches to the second state. In the second state,
ShowGIF monitors write and close calls. If the write is to
go to aforementioned file, ShowGIF intercepts the data and
decodes it to the screen before sending it along to DOS. If
it sees that the application is going to close the file one
of two things happens. It will either print "View
Successful" or "Transfer Aborted or File Incomplete"
depending on whether the decoder finished and switched back
to the monitoring state.
All this happens unbeknownst to the file transfer
software. The software assumes that it is performing normal
opens, writes, and closes. The upshot of this is that, from
the standpoint of the terminal program, downloads and uploads
with ShowGIF and uploads and downloads without ShowGIF are
Page 8
identical, or nearly so.
Modes of Detection
─────────────────────────────────────────────────────────────
Starting in ShowGIF 5.0, unlike previous versions, there
are two ways in which a GIF file can be detected. They are:
Detection by Filename-Extension
This is the original method of detecting GIF files. If
a file opens with the GIF extension, ShowGIF will begin
decoding. The advantages to this method are that it is very
simple and quick. The disadvantages to it are that it will
not detect a GIF file when the picture in circumstances such
as when the protocol uses a temporary name that does not have
the GIF extension (as in Procomm Plus and SeaLink) or when
the GIF file is in an archive.
Detection by File Streams
Detection by file streams works by monitoring the output
to all the open files, and checking this output for the
presence of the keyword "GIF87a." or "GIF89a" This will
detect a GIF file with any name and even if its part of
another file (such as stored in a ZIP file). Unfortunately,
this method may slow down drive access on the very slowest
computers (by slow I mean 4.77 MHz 8088) and may cause it to
start unnecessarily. (For instance, it would believe this
text file is a GIF because of the header string listed
above).
Memory Models
─────────────────────────────────────────────────────────────
There are three different memory model options available
to ShowGIF. These memory models actually refer to two
different .GIF decompressors. Each decompressor has its
particular advantage.
The Large model decoder uses a temporary output buffer
to greatly speed up the decoding process. This buffer
dramatically speeds up the decoding process, unfortunately,
this buffer increases the required overhead by about 45k.
This increase in overhead is unnoticeable in interactive
mode, but more than doubles the size of program in TSR mode.
The other disadvantage is that large single color areas which
occur in cartoon (hand drawn) .GIFs cause the buffer to
overflow causing the image to
have distorted bands.
Page 9
The small model overcomes the problem of using too much
memory and is completely accurate on cartoon .GIFs.
Unfortunately, it makes up for these improvements in a 40%
loss in speed. This mode is more ideal for the TSR mode.
The default memory model is a hybrid between the two.
When you select default, ShowGIF automatically utilizes the
large model viewer in interactive mode and the small model
viewer when it goes resident in the TSR mode.
Command Line Options
─────────────────────────────────────────────────────────────
/u Uninstalls ShowGIF. This returns all the memory
used by ShowGIF and restores the system vectors tapped
by ShowGIF. The Uninstall routine was repaired
somewhat, but if it still causes trouble, MARK &
RELEASE can be used successfully. A word of warning to
the wise: If you install ShowGIF and install another
TSR, then uninstall ShowGIF, memory will become
fragmented (not unlike fragmentation on your hard drive)
and your computer will probably lock up the next time
you load a program.
/eu:+
/eu:- Enables or Disables detection of GIF files by the
extension of their filename on file uploads. These
switches can override the setting made during setup.
/ed:+
/ed:- Enables or Disables detection of GIF files by the
extension of their filename on file downloads. These
switches can override the setting made during setup.
/su:+
/su:- Enables or Disables detection of GIF files by the
contents of the file input streams. These switches can
override the setting made during setup.
/sd:+
/sd:- Enables or Disables detection of GIF files by the
contents of the file output streams. These switches can
override the setting made during setup.
/p:+
/p:- Forces or prevents ShowGIF from waiting for a keystroke
after displaying the picture. This allows you to admire
the picture for a little bit after drawing is complete.
This will override any setting made in setup. You may
want to enable this feature for viewing GIFs in
immediate mode: "SHOWGIF /p:+ KYM256.GIF" or if you use
ShowGIF for viewing GIF files.
Page 10
/d:xxx Sets a delay for the result to remain on the screen
after viewing is complete. xx may range from 1 to 255,
and is proportional to the number of seconds (divide by
18.2)
/f:x Enables hardware handshaking on a particular port.
The number may be from 1 to 4 for the four standard COM
ports. This option must be instated at the command
line, there is nowhere in CSHOWGIF to use hardware
handshaking.
Hardware handshaking gives ShowGIF permission to
directly manipulate the modem flow control registers.
When this option is enabled, ShowGIF will block the flow
of data while it is decoding the picture and writing it
to disk. Only newer error-correcting (ARQ) modems will
listen to ShowGIF's request to block data flow. If your
terminal already supports hardware flow control (often
referred to as "RTS/CTS flow control" or "RTS during
write") you don't need to enable this option in ShowGIF.
However, if you experience numerous errors on an
otherwise perfect connection, try enabling this option.
'File' Displays a certain file then exits. (Immediate
mode). You may wish to use the /p:+ switch with this
command. An example would be "SHOWGIF BALLOONS.GIF" in
which showgif would merely display that picture then
exit.
/? Displays a help screen listing all the commands (except
/b)
/m:d Use default memory model. All of the /m switches
override the normal configuration.
/m:s Use the small memory model always
/m:l Use the large memory model always
ShowGIF messages
─────────────────────────────────────────────────────────────
Run-Time messages
These messages will occur after a picture is displayed:
"Bad Code In File" Usually means that the picture data is in
some way garbled. For those interested, it means that
ShowGIF encountered a Zev-Lempel code that exceeded the
acceptable range.
"Transfer aborted or GIF incomplete" The defined abort key
Page 11
was pressed and ShowGIF has returned to protocol's text
screen.
"View Successful" The picture passed through ShowGIF without
any flaws.
Installation Messages
These messages will occur when you are trying to load ShowGIF
"ShowGIF: Already Installed" ShowGIF is already ready to
use and won't let you install it twice.
"ShowGIF: /u requires that ShowGIF be installed" ShowGIF
has searched through memory and cannot find its resident
portion. ShowGIF was probably already uninstalled
"ShowGIF: Invalid switch" ShowGIF could not understand one
of the command line switches. Use ShowGIF /h to list the
valid switches.
"ShowGIF: Uninstalled" This just informs you that ShowGIF
has been successfully Uninstalled and memory freed.
Quirks
─────────────────────────────────────────────────────────────
Most quirks are due to ShowGIF's sensitivity to the
creation of a GIF file alone and not its origin. For
instance, COPYing a GIF file around also will kick in the
viewer.
Applications
─────────────────────────────────────────────────────────────
Bimodem
I have tested ShowGIF using Bimodem and haven't encountered
any specific problem but my beta testers have informed me
that ShowGIF has a tendency to skip every other file during a
bimodem transfer.
DesqView
The screen saver routine is capable of detecting DesqView.
If DesqView is resident, ShowGIF will avoid low-level video
I/O in saving and restoring the screen. This should allow
most implementations of DesqView to maintain control of the
video screen. Because the 8088 and 286 architectures are
Page 12
unable to dynamically remap RAM and maintain control of the
video memory, I don't recommend using DesqView on anything
less than a 386 based machine.
ShowGIF has been tested successfully in both text mode
(coresident with Qmodem) and in graphics mode (coresident
with Windows 3.0 standard mode) under DesqView 2.24 using an
Orchid Prodesigner II. Other setups should yield similar
results.
DSZ/GSZ
At normal speeds, we haven't experienced any problems with
DSZ, you can use ShowGIF with confidence.
At speeds at or above 9600 baud, you must enable hardware
handshaking in ShowGIF, using the /F:x option. If you don't
do this, GSZ/DSZ will loose data.
Procomm Plus
Testing with Procomm plus was successful. If you have
hardware flow control (RTS/CTS in ALT-S modem setup) you
shouldn't need to enable ShowGIF's own hardware flow control.
Zmodem writes its data immediately after obtaining it, so
there shouldn't be any problems. As always, ShowGIF will not
auto-resume along with the zmodem.
Other Protocols write the data in 10k steps, so you'll have
to wait for 10k of data to pass before ShowGIF can process
it. This will cause data loss to occur if you are using
ShowGIF with a 9600+ baud modem on a machine slower than a 12
MHz AT.
Qmodem
I personally feel that Qmodem is a fantastic terminal
program. I have not have any trouble with ShowGIF and Qmodem
since ShowGIF's initial development.
If you have a high speed modem, make sure that you have "RTS
during write" disabled. This really won't affect your
throughput, it should be automatically turned off if you've
used the quick modem setup. For best results, I recommend
setting the write buffer to the minimum size.
Telemate
ShowGIF can be used effectively with Telemate. You have to
keep several things in mind when ShowGIF is in use.
Foremost, I don't recommend doing anything fancy such as
opening additional windows during the transfer and trying to
multi-task. Secondly, be sure to familiarize yourself with
Page 13
the abort procedure. Unlike many terminal programs, which
accept a single "ESC" to terminate the transfer, you have to
hit "ESC y". You will not see the confirmation dialog box
when ShowGIF is active, so you will have to fly by instrument
or use the abort view command.
Telix
Telix somewhat defeats ShowGIF by writing data in fairly
large steps. If ShowGIF does not activate immediately after
the transfer starts, don't worry, it will eventually start.
Answers to Common Questions
─────────────────────────────────────────────────────────────
I'm using ShowGIF in immediate mode. The picture comes up
quickly then disappears. Is there any way to make it pause
at the end?
Yes: Use the command line /p:+ or turn pausing on in the
setup. Note that if you turn it on in the setup, you may
want it off in regular use, or else the screen will pause at
the end of a download!
Why won't ShowGIF sense when I'm downloading a GIF file?
Procomm Plus users will experience the problem. Fortunately,
ShowGIF 5.5 addresses this issue with stream detection. To
use stream detection give /s:+ command line or the change the
setup. What usually happens is that the terminal (or
protocol driver) makes a temporary file of some sort to be
renamed after the transfer. This file usually doesn't have
the GIF extension. Stream detection looks at the file
contents instead of the file name.
Why does showgif wait a very long period of time before
starting, and operate in widely spaced bursts?
Users of Telix's built in Zmodem may experience this
problem. Telix's sending its output to disk in large bursts
causes this problem. Since ShowGIF operates off these disk-
writes (not modem accesses), your problem occurs. The best
solution to this problem is to disable buffering. If you're
using a hard drive to download, the write time for each block
is negligible. If you cannot disable buffering, your other
options are to use a different protocol or an external
protocol driver, or just not let it get to you.
Why does a lockup often follow uninstallation of ShowGIF?
The most probable cause of this is installing something on
top of ShowGIF. Here is what happens, you install ShowGIF,
then you (mistakenly) install another TSR. After you finish,
Page 14
you uninstall ShowGIF with the /u switch. Now there is a 32k
unused 'hole' in your used memory. Next thing you know, a
different program tries to fit 200k of data into that 32k
hole. Since this data doesn't fit, it over-writes your TSR
in memory. Nothing seems wrong until you try to activate
this now nonexistent TSR...
This may be due to other causes. If you suspect ShowGIF is
conflicting with another program, be sure to let me know
about this problem.
Why won't ShowGIF view my more unusually sized pictures?
The addition of Stream Detection opened ShowGIF to various
vulnerabilities. The worst of which is the chance of
activating on Non-GIF format files. In order to protect
itself, ShowGIF will check to see if the information
following the GIF header is pausible. Horizontal resolution
must be between 320 and 1280. Vertical resolution must be
between 200 and 1024, among other things.
There is no real solution to this problem.
ShowGIF wraps the picture around several times in the middle
of the screen or Showgif gets past the first quarter of the
screen and locks up.
Recheck which configuration file you are using. The plane
switching method probably isn't correct, please be sure to
check the resolutions you're using with the test command in
the modes menu of CSHOWGIF.
My monitor goes nuts when viewing certain large pictures.
Your monitor may not handle the resolution that your card is
using. Be sure to test all of your resolutions using the
test command in the modes menu of CSHOWGIF.
What can I do about ShowGIF significantly slowing down my
file transfer?
Use a different protocol or a different driver. The one that
you are currently using depends on completion of drive
accesses before proceeding with the transfer. Since ShowGIF
slows down disk access, poorly constructed protocols may
suffer.
I'm concerned that ShowGIF will interfere with the transfer
itself.
There is no reason to worry about ShowGIF interfering with
the transfers themselves. ShowGIF operates transparently
with most protocols. The only noticeable effect (for the
Page 15
protocol) is that drive access will be noticeably slower (as
ShowGIF is both "un-GIFfing" the data and writing it to the
drive). If the protocol uses interrupt driven I/O properly,
no loss of speed will occur. Because ShowGIF operates with
the streams of data going to the disk, NOT the streams of
data coming from the modem, protocol reliability is not
affected.
What can I do if ShowGIF does not support my video card?
The best thing you can do in this case is to obtain a VESA
driver and install it before ShowGIF. ShowGIF will make use
of this driver in order to manipulate your card instead of
trying to directly manipulate it by itself.
What's New?
─────────────────────────────────────────────────────────────
1.0 a First version of SHOWGIF <Not released>
- Converted from an experimental standalone GIF decoder
into a decoder/viewer then into a TSR.
1.0 b Several features added: <Not released>
- Status report at the end of viewing (Not a gif, bad
code, etc.)
- Support for ATI, TSENG chipsets, separate versions of
the program
- Switch back normal video if d/l is aborted before
viewer is aborted.
- Squeezing pictures to fit 320x200 (MCGA version)
2.0 Several problems fixed: <Beta Test version>
- Code parsing routine completely re-written for speed
- Rest of the main loop translated into machine language
- Lockup after "Picture is not a GIF" message resolved
- Picture information put up while drawing
- Stack frame is normalized after each picture -- no
more lockup's after viewing 'too many' pictures
- 500% overall increase in speed! (benchmark 20 seconds
in 1.0 to 4 seconds in 2.0)
3.0 Improvements made <Beta Test version>
- Support for EGA (After lots of coaxing!)
- X axis scaling for pictures larger than 320 MCGA,EGA
3.5 Improvements made <First release!>
- One program can handle various video cards
Page 16
- Internal configuration for video hardware
- Support for 10 more video cards and several more
chipsets
3.7 Improvements made <Beta Test>
- 16 color (EGA) modes supported in standard VGA
configuration (640x350 and 640x480)
- Offset picture difficulties corrected.
4.1 Improvements made <Rare Second release>
- User definable resolutions (compatible with VPIC)
- Algorithm for deciding on a particular video mode re-
coded. Better judgement is used when choosing video
modes.
4.1b Cosmetic changes <Preferred second release>
- Mistake in "VGA.CFG" corrected (oops!)
- Thought I fixed the "text at the bottom of the screen
problem" but it still didn't work.
5.0 Beta version which leaked out.
5.1 Many Improvements made <Third release>
- Opening screen
- EGA routines GREATLY improved -- 3x's improvement in
speed
- Initialization translated into machine language
(except EGA color selection) for compactness & control
- Various sections carefully optimized for a 50%
increase in speed for VGA.
- EGA screen output GREATLY improved for about 250%
improvement in speed overall.
- Bug with viewing certain pictures which are
interlaced/smashed in EGA mode corrected
- File stream detection added.
- Checks the GIF header for information feasibility.
- Immediate mode GIF viewing.
- Control over the message delay after viewing.
- Optional press a key pause after picture display.
- Bios video functions disabled during view. (Note: if
this causes problems, it can be disabled with the /b
switch)
- More extensive command line options.
- Bug with uninstall corrected -- Sometimes it cannot
find the resident portion even if it is present! (I
think!)
- Problems with memory allocation fixed (Doesn't take
any more memory then it really needs -- only about
30k)
- Abort-view key made more responsive (though I don't
Page 17
really see a need for using it)
- On-demand screen blanker added.
- Ability to redefine the control keys.
5.1b Minor additions (Registered version only)
- Added TSENG4, AHEADB, ZYMOS plane switching
techniques.
5.5 Many changes <Fourth Release>
- New Interactive viewer, supporting slideshow, change
directory, move, copy, and erase files
- Decoders completely re-written and re-optimized, now
an additional 4 times faster than the Showgif 5.1.
- Support for tweaked 360x480x256 VGA
- Easy to use configurization program with autodetection
and a complete online manual
- Support for the new GIF89a standard
- Support for the new VESA standard
- Better screen saver: Able to save screens with sizes
other than 80x25 and custom character sets
- Support for DesqView
- Automatic detection and utilization of your machines
high memory (Qemm, etc.)
- Password protection of .GIF format files
Shareware
─────────────────────────────────────────────────────────────
If you've been using ShowGIF for longer than a month,
you should consider registering. For this version I'm
offering two plans are offered
Plan I: $15: You will be given a registration code which is
good for the latest version (only).
Plan II: $30: You will be given three full registration
packages along with a registration code which is good for the
version you registered and two thereafter. Each packet
includes a disk with the latest version of ShowGIF and a
bound and printed copy of the documentation.
Notification of new versions will be provided after either of
the plans expires.
If you wish to contact me, Call The Gif Cache at 419/531-2693
(24 hours, HST/v.32) or the Henrietta Outhouse at 216/965-
5463 (24 hours, HST) or you can send mail to
BILL PARQUET
30231 BATES RD.
PERRYSBURG, OHIO 43551-3827
Page 18
Software Credits
─────────────────────────────────────────────────────────────
I will give credit for all the software that I have
mentioned throughout this document.
**VPIC is a first rate picture file viewer and converter. It
has yet to be matched by anything else. 4.5 is the newest
version at the time of this writing. VPIC may be obtained
from:
BOB MONTGOMERY
132 PARSONS RD
LONGWOOD FL 32779
**GIF is a trademark of Compuserve, an H&R Block company.
**Qmodem may be the best communications program in existence.
4.31 is the newest version at the time of this writing.
Qmodem can be obtained from:
THE FORBIN PROJECT, INC.
POST OFFICE BOX 702
CEDAR FALLS, IA 50613
**Procomm Plus is a noteworthy terminal package made by:
DATASTORM TECHNOLOGIES, INC
POST OFFICE BOX 1471
COLUMBIA, MO 65205
**Telix is a noteworthy terminal package made by:
EXIS, INC
POST OFFICE BOX 130
WEST HILL, ONTARIO
M1E R4
**Mark & Release are TSR management programs and are
copyrighted by Turbo-Power software:
TURBO-POWER SOFTWARE
POST OFFICE BOX 66747
SCOTTS VALLEY, CA 95066-0757
Kudos
─────────────────────────────────────────────────────────────
I'd like to think a few people, without which, ShowGIF
would be far less complete.
Dave Sharpless: I'd like to thank Dave for writing the
interface for the interactive viewer and all of his useful
insights and ideas. Without his help, ShowGIF 5.5
would be much less complete!
Page 19
John Sharpless: Sysop of the Henrietta Outhouse III, For
bringing ShowGIF's success & distribution. ShowGIF would
probably only be used by the three of us and a handful of
people in Toledo if it weren't for him.
The ShowGIF 5.5 Beta Testers:
Jim Condon
John James Donaldson
Mike Lutheran
Dave Sharpless
Robert Novello
Michael Witt
GIF Boards
─────────────────────────────────────────────────────────────
These are a few boards which I am on myself and highly
recommend for obtaining .GIF format files at a reasonable
price:
The Gif Cache
419/531-2693
14.4k HST Dual Standard (v.32)
$5/Month (Optional)
BaudVille
313/848-8837
14.4k HST
Electric Blue BBS
908/241-7982
The McHenry BBS
815/385-7113,9011,9936,9013,9347
14.4k HST, v.32, Compucom
$60/Year (Req'd)
PriZm Image Center
508/697-3508 (v.32)
508/697-7771 (HST/v.32)
508/279-1552 (HST)
$8/Month (Volume discounts available)
NiteLog Imaging
408/655-1096 (2400 new user line)
408/655-8294 (HST/v.32)
408/655-8297 (HST/v.32bis)
Thank you for using ShowGIF!
Page 20