If you have a COM file that was written in Turbo Pascal that
does not work, or if it refuses to run with a RAM resident
program such as ZCPR or Xtra-Key, then read on. I just might
have a solution for you.
If the problem seems to be screen related, then the COM file
was not installed for your particular terminal
characteristics. If there is no install program provided,
and you have the source code, then all you have to do is re-
compile it on your machine with your correctly installed
TURBO.COM. If the source code is not available, then you
can install it yourself by using the GINST.COM program. You
can either use the one in the Turbo Toolbox (if you have it)
or use the public domain version found on our bulletin
boards.
On the other hand, if the program hangs up your system, then
the problem may be with the "End Address" option. This
command tells the compiler how much memory is available.
When you get into Turbo the End Address is automatically set
to the highest value it can be without conflicting with the
operating system. On my computer the End Address is set to
hex E540. If I produce a COM file on my machine and then
give it to someone with an End Address that is smaller (e.g.
D600), then the program will surely crash the other system.
This is not a good way to keep your friends.
If you get a COM file that crashes your system, and you have
ZCPR3 or some other RAM-resident software installed, then go
back to your original CP/M and the software has a better
chance of running. This is all you can do if you don't have
the Pascal source code.
If you do have the source, then the problem can be solved by
setting the End Address lower before compiling. To do this,
go to the Compiler Options menu by entering the letter "O".
Then select "C", which is the COM file option. Then the
Start address and the End address are displayed. Select "E"
to change the value and type in the new End address, e.g.
"A000" and hit return. If your program will compile
successfully with such a small End address, then you are in
business. If not, then raise the End address value until
the program compiles correctly. Run the software thoroughly
to make sure there are no run-time errors due to unavailable
memory.
Of course, some Turbo programs need all the memory they can
get. If so, then make sure all the other users of the
software are running straight CP/M, without all the fancy
RAM-eaters that people tend to use. These include RAM-
resident software like ZCPR3 and key definition programs.
If you have tried both of the above fixes and the COM file
still does not work properly, then you have a poorly written
piece of software. Send it back with your comments. On the
other hand, if the COM file begins to operate as advertised,
then walk tall with the realization that Murphy has been
defeated by your prowess.
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ealization that Mur
