DOS ain't dead

> I am using MS DOS 7.0. The question I have is what difference does the
> NOEMS parameter make when adding it to emm386?

In brief, using that switch pretty turns of the main reason for running EMM386 in the first place which is to support Expanded MeMory. To quote:

cc722864:
"...Provides access to the upper memory area but prevents access to expanded memory..."

fdos.org: EMS
"...Do not enable expanded memory. Use NOEMS to get more free UMBs if you need no EMS..."

Yahoo Answers: What is the difference between extended and expanded memory?

> Some programs do not seem to work anymore when this parameter is set. They
> do work if emm386 is run without it.
The programs that are not working will be the programs requiring EMS (Expanded Memory Specification) and the ones that are still working will likely be using XMS (eXtended Memory Specification) via HIMEM.SYS instead or not caring in the sense of using DOS memory or running with limited more support not immediately obvious, e.g. you might not be able to open as large files in these applications due to not having enough memory of the expected type, e.g. DOS memory and EMS (so the app just uses DOS mem).

Personally for years I've opted to always find alternatives of anything using EMS where at all possible as it slows machines down and many DOS Demo's won't run with it loaded. I'd liked Demo's and Windows 3.0+ never needed EMS... So for years I've not needed it either. EMS is one of those things that quickly went legacy that some programmers continued to use after they should of stopped and switched to using XMS or DPMI instead. /rant!

In closing, personally if you can avoid using EMS I'd always recommend NOT using it. Others may disagree...

> I am using MS DOS 7.0. The question I have is what difference does the
> NOEMS parameter make when adding it to emm386?

AFAIR the NOEMS does NOT actually "disable" EMS - a program may still allocate and use EMS pages. What it does is:

- rename the "driver" name from "EMMXXXX0" to "EMMQXXX0" ( programs wanting to use EMS are supposed to check the existence of this string at a certain location, but there's a significant amount of programs that won't do this )

- no page frame is allocated.

- the amount of EMS memory that can be allocated is limited ( IIRC, it's 8 MB; use the EMSSTAT utility supplied with Jemm to verify this assumption! ).

---
MS-DOS forever!

> I am using MS DOS 7.0. The question I have is what difference does the
> NOEMS parameter make when adding it to emm386?

NOEMS disables the EMS page frame (usually 64 K at E0000), and instead gives you 64 K more upper memory. you loose EMS memory allocation, though.


> Some programs do not seem to work anymore when this parameter is set. They
> do work if emm386 is run without it.
programs requiring EMS memory should be rare, as EMS memory was 8086 technology; from 80286 on XMS was much more common.

Tom

Thank you for your messages. On my PC it looks like there is no upper memory available if NOEMS is NOT added.

upper memory:
with NOEMS: used 15k free 67 k
without NOEMS: used 0k free 0k

If I run tlink when NOEMS is set, the PC boots.

Another question: does emm386 NOEMS use paging so the memory address returned from DOS when requesting additional memory (int21h/ah=48h) is not the physical address?

Georg

Now I tried JEMM386.exe instead of emm386.exe with MS DOS.

So in config.sys I have the line: "device=c:\jemm386.exe noems".

When I start tlink the PC does not boot any more instead I get the message:

"Unhandled exception 000E at 0020 1CAD Errcode 0002"

What does that mean?

I also found the following: if I start tlink a second and a third time from the command line without adding a file name to link, at the third time everything works fine. The same happens when I load TD, the debugger, from the command line. This starts fine on the third time and thereafter.

So is there a way to get tlink to run on the first time

Georg