Bulletin number:  4r
Products affected: D700D
Description: Error in call.interrupt routine
Component: 
Date: Tue Jan 30 09:30:00 GMT 1990
-----

The routine call.interrupt interfaces to the Micrsoft INT86 routine.
Unfortunately there is confusion in the way data of type char is
handled.  This means that bytes with values over 127 are sent as
negative numbers.

There is a fix:

In the routine call_interrupt_call the value to be transfered to the
cx register is loaded into the parameter list for INT86 and then INT86
is called.

The two lines (which appear a few lines before the call to INT86):

value = input[count + 1];
value = (value << 8) | input[count];

should be replaced by:

value = input[count + 1] & 0xFF
value = (value << 8) | (input[count] & 0xFF);

and the system should be rebuilt according to the instructions in
TOPLEVEL.TOP.