On Sat, Aug 5, 2017 at 12:28 AM, Tony Cappellini <cappy2...@gmail.com> wrote:
>> This gives access to most of the 4GB of RAM
>>>Really, so much? How's that possible?
> Depending on which motherboard we use, we get between 2.x-3.x GB, but never
> the full 4GB.

I see the same, but how exactly do you "get" it? For me, it's from
XMSv3 driver (e.g. HIMEMX). Others (e.g. DPMI servers) may report
higher or lower amounts but are not always reliable due to limits or
bugs or whatnot. (Actually, I think FD MEM supports /x and /e for

>>>I personally never use extended memory, because there are very few
>>> programs able to exploit it.

Are you sure? XMS is very common. Or maybe you meant "raw"? True, it's
not nearly universal (except when masked behind DPMI server), so a lot
of apps necessarily don't hardcode support for it (especially these

>>> For me using a memory >>extender most of time
>>> results in anything more than a waste of conventional memory.

XMS isn't really an "extender" (in the sense of DOS4GW or WDOSX or CWSDPMI).

On one setup of mine, here's the layout:

COMMAND (4K) -- FreeCOM 0.84-pre2 XMS_Swap
SHSURDRV (0K ... actually 400 bytes) -- RAM disk
PCNTPK (18K) -- packet driver

Free:  610,544 bytes (596K)

Seriously, if that's not enough for a single app, it is *extremely*
greedy! It is very very rare (to me) to need more than 600,000 bytes
free. (But of course DOS has decades worth of programs, and not all
are well-behaved.)

> If I don't load umbpci, then the target app won't be able to run.

How much is free without UMBPCI? What error message do you get?

> The target application is a legacy tool that has been in use for over 20
> years, where I work. We don't have the sources, nor the build environment,
> very little documentation, nor the expertise / time to modify if, if we did
> have all of those. It is an extremely useful tool for us, however the DOS
> environment is tough to configure. (mostly because none of us understands
> how to load/configure the minimal drivers to get the maximum memory). We've
> been struggling for almost 20 years, we have a configuration that works
> under MSDOS, but we are very tight under the 1MB area. And, this changes
> from one motherboard to the next.

Again, it would be nice to know exactly how much free you're seeing
versus how much you actually need.

>> DEVICEHIGH=RAMDRIVE.­SYS /E 20000 512 256
>>>If you have a RAM disk manager configured in fdconfig.sys too, you'd
>>> better disable it for the moment; I encountered >>several issues using a
>>> turbodisk to create a large ram disk with expanded memory loaded.
> This is a requirement for our test environment. The Ramdisk loads fine in
> MSDOS, which is what we use at the moment.

FreeDOS has SRDISK, TDSK, RDISK, SHSURDRV ... and I'm sure there are
more that I'm forgetting.

> The contents of the config.sys I posted are the contents for a successful
> boot configuration under MSDOS.
> I'm not loading the Ramdisk in Freedos - yet.
>> SHELL=C:\4DOS.COM /F /P /E:2048

I don't regularly use 4DOS, but IIRC it various kinds of swapping
(EMS, XMS, and disk). But FreeCOM also has XMS swapping.

BTW, 2048 for environment is overkill (unless you personally are
absolutely sure you need that much). 1024 would be more reasonable ...
although it won't save you much. (Same with FILES=80, I forgot that
wastes a tiny bit more, but it won't save you much. Also try a low
LASTDRIVE setting, default is E. And remove BUFFERS entirely or set it
to -1 if you're that low on RAM!)

> Will keep that in mind for troubleshooting, but command.com will break our
> test environment. WE rely heavily on many features of 4DOS.

For the app itself or just accompanying in-house scripts? I would be
surprised if the app itself required 4DOS, but who knows.

BTW, which version of 4DOS are you using? 7.50? 8.00? Other?

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