Contents of the QUICKCRT.DOC file
QUICKCRT Fast video I/O program. Version 1.00
Copyright (C) 1986 Tony Overfield
QUICKCRT will speed up any screen access that is made through
BIOS, whether directly or through DOS first.
QUICKRT is a collection of highly optimized assembly language
routines designed to speed up programs that are screen
intensive, but use BIOS calls to maintain BIOS compatibility.
QUICKCRT is a replacement for the routines in ROM that handle
screen display functions. Programs that do not use BIOS are
QUICKCRT installs itself as a DOS extension, taking less than
2k bytes of memory. Immediately after installation, any
program that calls BIOS for screen output, including DOS
itself, will benefit from QUICKCRT.
Many programs use BIOS calls for all text display functions to
maintain compatibility across numerous computers, video
adapters, and windowing environments. This approach has the
advantage of working on many computers that are not IBM
hardware compatible. The disadvantage is the reduced
performance on IBM compatible hardware. QUICKCRT was designed
to reduce, or even eliminate, that disadvantage. For users
that have an IBM compatible computer and an IBM compatible
video display adapter, QUICKCRT will replace the BIOS routines
with RAM resident hardware specific routines that are optimized
for the display in use.
Programs with highly interactive user interfaces, benefit the
greatest from QUICKCRT. Several major programs such as DBASE
III, RBase 5000, and even BASIC and DOS itself greatly benefit
from the higher display speed provided by QUICKCRT.
Flight Simulator and JET both require that you do not install
QUICKCRT before running FS or JET from the DOS prompt. These
two programs (and possibly some other game programs) clobber
DOS, and all other programs in memory, including QUICKCRT.
I developed QUICKCRT over two years ago and I have used it
constantly since then without any problems. If any problem is
discovered, please let me know.
QUICKCRT supports color display adapters that require
synchronized access to the video RAM. This requires waiting for
the specific intervals where screen updates are allowed by the
hardware. Therefore, the /S mode is slightly slower than the
/F mode, although it is still much faster than the BIOS
routines. This mode is selected with the /S command line
switch. QUICKCRT is smart enough to ignore the interval checks
for monochrome display adapters, whether the /S option is
enabled or not. Only when the color graphics adapter is
active, and the /S option is enabled will the checks be made.
To speed up the output of any program that uses the BIOS
calls to display text output.
IBM compatible video display adapter.
All calls to the original BIOS routines are supported,
with the exception of multiple screens on the color
Multiple text screen pages on the color display adapter
are not supported, and will give strange results. Screen
modes other than 80 column 25 line text and all graphics
modes are passed through to the original BIOS routines.
QUICKCRT "wakes up" when the 80 by 25 text screen is
- Prints short help
- Installs or re-activates the Fast mode of QUICKCRT
- This mode does not check for retrace intervals
- Use this mode if you don't see interference patterns
- Installs or re-activates the slower mode of QUICKCRT
- This mode checks for retrace to avoid interference patterns
- Use this mode if you see snow with /F
- Deactivates QUICKCRT
- QUICKCRT remains in memory, ready to be re-activated
- Prints a test pattern to the screen
- Use this option both before and after installation of
QUICKCRT if you want to see the performance difference
Every attempt has been made to ensure that QUICKCRT performs as
represented and is free from bugs, flaws, and errors.
In no event will the author of this program be liable for any
loss or damage arising from the use or misuse of this program.
This program is provided as is, with no warranty as to its
suitability for any specific task.
QUICKCRT may be freely copied, shared, and placed on public and
private bulletin boards, but may not be sold under any
>>>>>>>>>>>>>> The author retains the copyright <<<<<<<<<<<<<<
ALL RIGHTS RESERVED.
Please do not alter the code or remove copyright notices from
any copies uploaded to bulletin boards. Please upload both the
program and the documentation.
QUICKCRT is being distributed as a "User Supported" program.
If you find it useful, I ask that you send me a contribution.
Any amount that you feel is appropriate would be appreciated,
although contributions of $15 or more puts you on my mailing
list. You will then be notified of updates to this program, as
well as information on other programs available from me.
Contributions of $35 or more entitle you to the source code to
Even if you choose not to contribute, PLEASE send me a comment
letting me know how you got a copy of QUICKCRT and how you like
it. Comments are encouraged and welcomed!
User-supported software is a matter of trust. The user-
supported system not only encourages the creation of quality
software but makes it available to individual users at a
reasonable price, unaffected by the high costs of media
advertising and undesirable copy-protection schemes. Users are
free to evaluate a program in their own homes or offices and at
their own pace, without risk. The user-supported system of free
software distribution can only survive, however, if the
commitments of time and effort on the part of program authors
continue to be supported through the voluntary payments made by
satisfied users. I encourage you, therefore, to copy and
distribute this program for evaluation by others -- and I trust
you to forward payment in registration of your own copy if you
enjoy and continue to use it.
If you would like to register as a user of QUICKCRT send your
1201 Harvey Rd #169
College Station, TX 77840
If you have any comments, suggestions or ideas about the
QUICKCRT program, then please contact me by U.S. Mail or by
E-MAIL at FIDO 117/1267. Thank you.