Q63040: LINK /F of Overlaid BRT70xx Program Causes "Invalid Runtime"

Article: Q63040
Product(s): See article
Version(s): 7.00
Operating System(s): MS-DOS
Keyword(s): ENDUSER | SR# S900615-62 buglist7.00 fixlist7.10 | mspl13_basic
Last Modified: 6-AUG-1990

LINK-overlaid programs using the BRT70xxx.EXE run-time module from
Microsoft BASIC Professional Development System (PDS) version 7.00
should not be LINKed with the /F (/FARCALLTRANSLATION) option. When
this is done, a CALL to an overlay causes an attempt to reload the
run-time module. This results in an "Invalid runtime module" message
and, in most cases, the machine hangs.

To work around this problem, LINK without the /F option or compile
for a stand-alone .EXE (with the BC /O option).

Microsoft has confirmed this to be a problem in Microsoft BASIC PDS
version 7.00. This problem does not occur in BASIC PDS 7.10.

The /F (/FARCALLTRANSLATION) LINK option is described on Page 241 of
the "Microsoft CodeView 2.3 and Utilities User's Guide" for Microsoft
BASIC PDS version 7.00 for MS-DOS. Using this option may produce a
slight gain in speed and size of executables by translating far calls
to near calls. However, attempts to optimize overlaid calls cause a
problem with the run-time module. Thus, /F should not be used with an
overlaid program that is using the run-time module.

Code Example
------------

The following programs (which are separate .BAS source files)
compose a simple overlaid program that demonstrates the problem:

CALLOVL.BAS
-----------

INPUT "Call overlay (Y/N)? ",i$
IF ((i$ = "Y") OR (i$ = "y")) THEN CALL test
END

OVL.BAS    **** NOTE: This is a file separate from the above file!
-------

SUB test
  PRINT "in overlay"
END SUB

The following are the compile and LINK lines to demonstrate the
problem with the above separate modules:

   BC CALLOVL;
   BC OVL;
   LINK /F CALLOVL+(OVL);

These programs can be run properly if either /O is added to each BC
command line or the /F is omitted from the LINK line.