Hi
Clarence Verge <[EMAIL PROTECTED]> wrote:
>> But IMHO no real mode and therefor no DOS.
>> But what should they do with it ??
>> Do you want to run a single user, single task OS with a 640 KB
>> memory limit on a processor <snip>
CV> I have been trying to avoid getting sucked into this discussion but
CV> the temptation is just too strong. <G>
;)
CV> I would like re-work a few points and will try to begin with fact and
CV> move toward opinion.
CV> 1) Fact: The Intel 8086 and 8088 do not have any built-in 640k limit.
but they were designed to be only able to address 1 MB.
(and had an error which made it possible to access additional 64 KB (HMA))
Don't forget that we are talking at least about many MBs of memory ...
so it's not important if it is a 640 KB a 1 MB a 4MB or wathever limit.
CV> 2) Fact: DOS does not have any inherent 640k limit. If you experience
CV> what appears to be a 640k limit, this is due to your choice of
CV> hardware. Some bioses assume VGA and will not let you use more than
CV> 640k. If you doubt this, remove your VGA card, install a Hercules
CV> card and tell any decent bios you want 704k low.
DOS was written for real mode.
In real mode you can address only slightly over 1 MB of RAM.
'Todays' computers come equipped with at least 128 MB of RAM ....
you see the discrepancy.
CV> 3) Fact: DOS means Disc Operating System. There is nothing preventing
CV> a DOS (16 or 32 bit) from being multi-user or multi-tasking - except
CV> finding an author.
but the OS does not aid.
I had a multitasking program on my c64 ;)))
You don't need DOS to use these programs ...
you can simply write a bootloader for it, and use it without DOS.
CV> 4) Fact: There is nothing preventing someone from writing a 32bit DOS
CV> except economics and compatibility with sub '386 processors. 16Bit
CV> DOS code could run in this 32bit DOS.
The question is ... WHY ?? :))
CV> 5) Fact: A 32bit OS provides no inherent advantages over a 16bit OS
CV> except for allowing FATWARE programmers to access more memory faster.
?? what's the problem with using your ressources ??
CV> 6) Fact: A 32bit OS doesn't necessarily exclude use of REAL mode.
yes ... but it is highly unlikely that somebody would do that.
he would end up with all the limitations of the real mode.
And would have no advantages ! (address limit, lack of memory protection)
CV> 7) Fact: Himem.sys uses a 32bit mode called Flat Real Mode to access
CV> your memory. This mode allows DOS to access 4 Gb of memory as long as
CV> you don't use any protected mode applications (such as memory
CV> managers). See: http://www.csoft.net/~johnfine/segments.htm
the memory is not directly available to dos !!!
himem uses a buffer and copies the needed data there, this is slow ...
so why slow down things when you can have direct access to memory ???
CV> 8) Opinion: I'm prolly gonna get flamed.
don't forget that your on arachne list ...
(nearly) all people here like/love dos :)))
But we should keep an eye on reality.
M$ (the company which made DOS big) wanted to abandon DOS as the i386 came
out, because DOS was not able to use the advanced features that this
processor offered.
CV> - Clarence Verge
CU, Ricsi
--
Richard Menedetter <[EMAIL PROTECTED]> [ICQ: 7659421] {RSA-PGP Key avail.}
-=> Sacred cows make the best hamburger - Mark Twain <=-
