Morris Jones

Date: Thu, 13 Jun 2002 22:02:01 -0700

Mr. Brandon Robinson, MCSA MCP MCSE
Windows Enterprise Support
Windows 2000 Support
Applications and Performance
Microsoft Corporation
16011 NE 36th Way
Box 97017
Redmond, WA 98073 9717
Subject:   SDS Memory


The SDS program is a 16 bit DOS program. It uses "16 bit Segment" pointers, and is very old. All memory was allocated in 16 byte chunks. It can use the memory above 640K, but not the memory above 1MB. It other times, the program used memory that was "dealocated" from peripherials. (Graphics adaptors, EMM, basic ROM area, and things like network adapter reserved RAM. Segments A,C,D,E).
Is there a way to make this memory available to this old application. (The memory allocator could be modified easily). The program is written in assembly language, and changing the pointer and data structures would be a complete rewrite.
The solution may consist of making the address space available to the DOS box, and then having a way to recognize and allocate this memory to the application. A smaller DOS low memory image is also a help. Fewer file control blocks, etc.




Morris E. Jones

Copy to:

  1. Brenda Cannon,
  2. Rod Welch,