QBX & BC /Es Option Shares Expanded Memory with Mixed Language (59402)

SUMMARY

This article discusses the /Es (share expanded memory) option for QBX.EXE and BC.EXE in Microsoft Basic Professional Development System (PDS) Versions 7.00 and 7.10 for MS-DOS.

The BC /Es Option

The /Es option for BC.EXE needs to be added to the list of BC options on Page 559 of the "Microsoft Basic 7.0: Programmer's Guide" for versions 7.00 and 7.10.

The BC /Es option is correctly described on Page 608 of the "Microsoft Basic 7.0: Language Reference" (Appendix C: "Command-Line Tools Quick Reference") for 7.00 and 7.10. The BC /Es option is also correctly documented as follows in the Microsoft Advisor online Help system in QBX.EXE, found by choosing Contents from the Help menu, then selecting "BC Command Line":

   "HELP: BC Command Line"
   /Es       Allows you to share expanded memory between Basic and
             mixed-language routine(s) that make use of expanded memory.
             Specify /Es when you are going to use a mixed-language
             routine that makes use of expanded memory.
				

NOTE: The only way an .EXE program compiled with BC.EXE can use expanded memory is with ISAM file buffers, or when linked to use overlays, as described in a separate article found with the following query:

The QBX /Es Option

QBX.EXE, the programming environment included with Microsoft Basic Professional Development System (PDS) Version 7.00, can use expanded memory for procedures smaller than 16K.

Note that the QBX /Es option cannot be used together with the /Ea option. (The QBX /Ea option lets each non-variable-length string array smaller than 16K use one 16K page of expanded memory.)

By invoking QBX with the /Es switch, QBX can share expanded memory with mixed-language routines (in Quick libraries) that make MS-DOS interrupts to access expanded memory.

The QBX /Es switch is correctly documented on Page 626 of the "Microsoft Basic 7.0: Language Reference," and in the Microsoft Advisor online Help system in QBX.EXE, found by choosing Contents from the Help menu, then selecting "QBX Command Line":

   "HELP: QBX Command Line"
   /Es      Allows you to share expanded memory between QBX and
            Quick libraries or mixed-language routines that make use
            of expanded memory. Specify /Es when you are using a
            Quick library or mixed-language routine that makes use
            of expanded memory. Do not use /Es with the /Ea option.