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- April 16, 1987
-
- CBOOT Version 2.0
-
- I would like to thank all of the people who sent me money for
- version 1.0 of CBOOT. This little program has proved to be far more
- useful than I ever guessed and the only public domain program I
- have written that ever made any money. For those of you who use
- CBOOT and don't send any money - Grrr!
-
- CBOOT is a very simple memory resident program which watches the
- keyboard interrupt. waiting for someone to press the Left Shift,
- the Alt key and the "B" key all at the same time. When this happens
- a small menu appears on the screen. The menu allows you to re-boot
- your PC in one of two ways. It allows you to issue a control-break
- and it allows you to attempt an exit of your program. A new item,
- restoring interrupts, is new with version 2.0.
-
- The program works best under DOS 3.x, but will also work on DOS 2.x.
- I have used some undocumented features of DOS to make escape from
- run-away programs a little easier, and it appears that DOS 2.1 works
- a little differently than 3.2 and the result is that escaping from a
- program may not always clear memory under DOS 3.2. (My own opinion is
- that DOS 2.1 is a better DOS, but I am running a network and have to
- use 3.1 or 3.2).
-
- MENU ITEMS:
-
- 0. Exit.
- Press 0 or Esc and get out of cboot and return to what you were
- doing.
- 1. Reboot (Ctrl-Alt-Del).
- This is the same as pressing the Ctrl-Alt-Del warm boot
- (three finger) combination. It is useful for programs which
- have disabled the keyboard Ctrl-Alt-Del.
- 2. Reboot with Memory Check.
- This is a Cold type boot and the system does its memory check.
- 3. Break (break-key).
- This is the same as pressing Ctrl-Break. CBOOT issues interrupt
- 1B which may or may not help you out of a bad situation.
- 4. Exit Current Program.
- CBOOT issues interrupt 20h which is the traditional way to
- exit programs. Memory may or may not be restored. Do a CHKDSK
- to see if you got all fo your memory released.
- 5. Break Current Program.
- I have found that if you issue the DOS Break interrupt and then
- exit through interrupt 20h you sometimes have better results.
- If 4 doesn't work try this one.
- 6. Exit through Function 4C.
- This one seems to always give back the memory and close all
- the files, except once in a while (if Dos is in bad shape) it
- can cause the system to act odd. Experience will tell you if
- this works well with your programs. Use this one for disgraceful
- exits from basic after resetting the interrupts.
- 7. Reset Interrupts.
- Cboot remembers what the interrupts were when it started up.
- It can restore them. This must be done to exit out of Basic
- as basic does strange things with the interrupts. The only problem
- is that you loose any hooked memory resident programs that were
- loaded after CBOOT. And since Sidekick must be loaded after
- CBOOT - there goes sidekick and 64k of memory.
-
- INSTALLING CBOOT.
- Put CBOOT in your autoexec.bat or else load it just before you
- work on a particularly nasty program. There are no command options.
- CBOOT takes about 2k of memory. Sidekick will get upset with CBOOT
- if CBOOT is loaded after it. I think that Sidekick is not a very
- well behaved program and it is banned from my system. It can be
- very useful, but it is abusive of resources and makes programming
- memory resident stuff difficult.
-
- If you have any questions, drop me a line at:
- Keith P. Graham
- 238 Germonds Road
- West Nyack, New York 10994
-
- Remember to send the 5 bucks. If you can't afford it think of me
- when you hit the lottery.
- Keith
-