Category : Communication (modem) tools and utilities
Archive   : CA29-4.ZIP
Filename : OVERLAY.DOC

Output of file : OVERLAY.DOC contained in archive : CA29-4.ZIP
910710 COM-AND Script Overlay Page 1
Included in this release is a file overlay archive. It contains:


Assembler source file. Compile with "MASM OVERLAY;". This file
defines two overlay routines, one to display a string through
BIOS, and a second to return the segment address.


MASM output from compilation of OVERLAY.ASM. Link with the
command "LINK OVERLAY;" to create EXE file.


LINK output. Not directly executable! Properly, would be renamed
to OVERLAY.OVL to prohibit running from the DOS prompt. Convert
to COM format with the command "EXE2BIN OVERLAY.EXE OVERLAY.COM".


EXE2BIN output. Not directly executable! Could be renamed as
OVERLAY.OVL (as above) to prohibit running from the DOS prompt.
Whether the COM or EXE file is used, the script must have the
proper file name for the executable.


COM-AND script to use OVERLAY.EXE or OVERLAY.COM. This script,
when invoked, loads the OVERLAY.EXE (or COM if you change it),
and then invokes the two entry points in the overlay.

This overlay requires no 'cleanup' on termination. Therefore the
script that loads it does not set an exit script to terminate the
overlay in an orderly manner. Similarly, no end-entry address is
specified in the OVERLAY statement for execution upon termination.

Albeit not a very interesting function proper, OVERLAY demonstrates
the coding and use of machine language subroutines to COM-AND scripts.
Overlays may be coded to interface DOS and BIOS interrupts, or more
sophisticated modules such as the demonstration TALKER.*. Enjoy!

  3 Responses to “Category : Communication (modem) tools and utilities
Archive   : CA29-4.ZIP
Filename : OVERLAY.DOC

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: