Mail Archives: opendos/2000/12/07/03:27:20
> > -----Original Message-----
> > From: Da Silva, Joe
> > Sent: Monday, 4 December 2000 11:45
> > To: 'opendos AT delorie DOT com'
> > Subject: RE: Misc. (was BASIC & EMS, nee Optimizing CONFIG.SYS...)
> > 1. FYI : We all agree the 8088/8086 was a very stupid choice
> > by IBM and is the reason we now have all these issues. The
> > reason they chose this *very* poor performance chip, instead
> > of the 68000 or Z8000 (both good performers, although I think
> > Z8000 also uses segmented memory - yuck!!!) is that :
> > a) They already had an 8085 design, which they could quickly
> > "rehash" to use the 8088 chip.
> > b) They had a license agreement with Intel, to make the 8088
> > or 8086 chip themselves.
I'm not sure that is true or if it was that came a lttile later. IBM was
actually going to use the 8080 chip for thier PC. Gates suggested to them
that they use the 8086/88 when they started looking for an OS for thier PC.
Those that you mention above, may have come after that. We are talking a
time frame of less than one year between the time Gates was contacted for an
OS and the first release of the PC. Most people refere to thei as the PC-1.
The offical PC came out six months later in Sep 1981 which is often called
the PC-2..
Imagine if IBM had actually used the 8080 for their PC! They would have been
two or possibly three generations of chips behind the rest of the industry.
I have seen several such references to this in articles in Byte and other
magazines. SCP and other companies had already been using the 8086 in their
computer designs before IBM even decided to get into the PC market. The 8086
had already been developed long before that. The 88 was a more recent
development and as you say, it could be plugged into a system in place of
the 8085. But this was long before IBM entered the picture. Kaypro and other
companies used this long before the IBM PC came out.
> > 2. What is DV (some multitasking thing mentioned ...)?
DV is Quaterdeck's Desqview which is a multitasker. They also made DVX which
is another multitasker which is a lot like X (some peole say X-windows.) It
was very good for it's intended purpose and the restrictions of DOS. I used
it a lot and several BBSes around here used it for multi-node operation. It
worked nicely with PCBoard. Some Wildcat users also got it to work.
> > 3. FYI : My 4x and 6x CD-ROM drives _don't_ make shrill
> > spinning sounds, but my 40x CD-ROM does! This tells
> > me that indeed, my 40x drive spins *much* faster than
> > my 4x or 6x drives, so this "40x" stuff is real, not a
> > marketing fiction for drives that just have data buffering ...
I don't recall what the speed was that they no longer increased the physical
rotation speed of the CDROMs, it was 8, 12, or 16, but after that it is just
a RAM buffer. I do not recall the articles where I read about this and it
was quite sometime ago. Sure you have a shrill sound because it is much
greater than the 4x you had.
> > 4. Is it really possible to split the EMS page frame into, say
> > two 32K chunks? This would be a very "handy" thing - for
> > instance, 32K could "live" on top of the VGA BIOS, using
> > Stealth (not Cloaking, right? ;-) techniques, and the other
> > 32K could "live" on top of the F000-F7FF BIOS region (MP
> > says this is possible for 90% of machines ...). Great stuff,
> > but it sounds "too good to be true", doesn't it???
It is supposed to be able to do this and even use 4 16k chunks, but I have
never seen it done and have never seen any docs that show how to do it with
any EMM386 driver including QEMM and a few others. In the book "DOS Beyond
640K" it tell's the spcifications of both LIM 3.2 and 4.0 and it states that
you can use 4 different areas of memory for each 16K. Also you are not
restricted to just 4 16k pages, you can use more than that. But I have never
seen nore than a 64k page frame either. DV did do something along those
lines, but not the memory manager itself. I don't recall the details right
off hand but remember reading about it somewhere in the DV docs.
Pat
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