Patching Turbo Pascal

The Problem:

Turbo Pascal v.7 for DOS programs which contain the code

uses
   CRT

may freeze up or produce a "Divide by zero" error on machines with speeds greater than about 200 Mhz. This error occurs when the CRT unit attempts to measure the speed of the machine. In order to measure the speed, it runs a timing loop and then does some division to produce an average speed. On very fast machines, this average ends up being a number larger than the program (in its current form) can store. For technical reasons, this generates a divide by zero error.

The Cure:

You must fix your version of Turbo Pascal by applying a patch.

Download the bp7patch.exe patch file into the Turbo Pascal v.7 \bin folder for your machine (the folder will have a name such as C:\Borland\turbo7\bin).
Go to a DOS prompt, and change to the Turbo Pascal v.7 \bin folder.
Determine the minor version number of your version of Turbo Pascal by looking at the creation time for the TURBO.TPL file. The command DIR TURBO.TPL will display this. The result will be one of
```
    TURBO.TPL  48,432  10-27-92  7:00a
    TURBO.TPL  48,464  03-09-93  7:01a 
```
depending on whether you have version 7.00 or 7.01.
Backup your program files in case of catastrophic error:
```
    MKDIR BACKUP
    COPY T*.* BACKUP
```
Uncompress the archive (this is a self-extracting archive file):
```
    BP7PATCH
```
Install the patch:
```
    PATCH PATCHxxx
```
where xxx is replaced with 700 or 701, depending on the minor version number of your software.

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