Q39256: QuickBASIC May Not Function with 25-MHz 80387 Coprocessor

Article: Q39256
Product(s): See article
Version(s): 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | SR# S881212-11 | mspl13_basic
Last Modified: 4-SEP-1990

Customers have reported that QuickBASIC version 4.50 does not function
correctly with a 25-MHz 80387 math-coprocessor chip. The reported
problems include the following:

1. Incorrect floating-point numeric results

2. Coprocessor not detected

The problem does not occur on 80387 chips slower than 25 MHz.

Microsoft has not tested QuickBASIC version 4.50 with 25-MHz 80387
chips.

To test potential problems, you can compare numeric results with and
without the coprocessor by turning the coprocessor on or off. The
following command in MS-DOS turns off access to the coprocessor in the
current boot session (where any message with one or more characters
must follow the "="):

   SET NO87=Coprocessor is currently disabled.

The following command makes the coprocessor accessible again (where no
characters follow the "="):

   SET NO87=