[comp.sys.ibm.pc.misc] 386SX capabilites

fordke@infonode.ingr.com (Keith Ford x8614) (10/10/90)

I checked the Frequently Asked Questions file, but no help there.
I know a 386SX is said to be functionally equivalent to a DX, but
is there anything it cannot do, other than the obvious 32-bit bus
accesses.  Email replies requested to save bandwidth.  TIA-kef/MM-
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kaleb@thyme.jpl.nasa.gov (Kaleb Keithley ) (10/10/90)

>I checked the Frequently Asked Questions file, but no help there.
>I know a 386SX is said to be functionally equivalent to a DX, but
>is there anything it cannot do, other than the obvious 32-bit bus
>accesses.  Email replies requested to save bandwidth.  TIA-kef/MM-

Let's all sing the 386 song: 
(sung to the tune of the Beatles Revolution no. 9)

A 386 is
A 386 is
A 386 is
A 386 is....

Even if it's an SX.  There's nothing a DX can do that an SX can't.

-- 
Kaleb Keithley                      Jet Propulsion Labs
kaleb@thyme.jpl.nasa.gov

causing trouble again.

davidsen@sixhub.UUCP (Wm E. Davidsen Jr) (10/14/90)

In article <1990Oct10.001733.1299@thyme.jpl.nasa.gov> kaleb@thyme.jpl.nasa.gov (Kaleb Keithley	) writes:

| Even if it's an SX.  There's nothing a DX can do that an SX can't.

  Whoops! The 16 bit data bus prevents doing 32 bit i/o to memory mapped
devices, and the addressing space is only 16 MB.

  I believe those are the major diferences.
-- 
bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc and 80386 mailing list
"Stupidity, like virtue, is its own reward" -me

kaleb@thyme.jpl.nasa.gov (Kaleb Keithley ) (10/15/90)

In article <2056@sixhub.UUCP> davidsen@sixhub.UUCP (bill davidsen) writes:
>In article <1990Oct10.001733.1299@thyme.jpl.nasa.gov> kaleb@thyme.jpl.nasa.gov (Kaleb Keithley	) writes:
>
>| Even if it's an SX.  There's nothing a DX can do that an SX can't.
>
>  Whoops! The 16 bit data bus prevents doing 32 bit i/o to memory mapped
>devices, and the addressing space is only 16 MB.
>

Got any memory mapped devices in mind?  We are talking about Intel 
architecture here, not Motorola ;-)  Accuse me of "small world" if you
want, I haven't seen memory mapped i/o for PC's in ten years, that's
what the i/o bus is for.  As for memory, yeah, you're right, but how
many people do you know who are using DOS are being limited by the SX's
16Meg limit?  I don't know anyone, including UNIX and OS/2 users.  How 
many people are being limited by DOS's 640K limit?  Everyone.  Remember, 
not everyone has DesqView/QEMM or Windows 386/3.0

Actually, I think I'll let this whole thread go, since I just upgraded
my 386SX to a 486 (Can you say $1100?)  Defending my SX from ignorance 
has become a non-issue to me.  Anyone want to buy a slightly used 386SX 
w/ 0k, plus an AT case and 200W p/s?  It has run DOS, OS/2, ESIX SysV 
UNIX, DesqView/QEMM, and Windows 386.  Up to 8 Meg on the M/B, AMI BIOS, 
C&T chipset.

-- 
Kaleb Keithley                      Jet Propulsion Labs
kaleb@thyme.jpl.nasa.gov

causing trouble again.

rcollins@altos86.Altos.COM (Robert Collins) (10/16/90)

In article <1990Oct15.161015.417@thyme.jpl.nasa.gov> kaleb@thyme.jpl.nasa.gov (Kaleb Keithley	) writes:
>>  Whoops! The 16 bit data bus prevents doing 32 bit i/o to memory mapped
>>devices, and the addressing space is only 16 MB.
>>
>
>Got any memory mapped devices in mind?  We are talking about Intel 
>architecture here, not Motorola ;-)  Accuse me of "small world" if you
>want, I haven't seen memory mapped i/o for PC's in ten years, that's
>what the i/o bus is for.  

Try being a BIOS programmer and dealing with custom and standard chip 
sets.  We have memory mapped I/O on lots of machines in the address
ranges from 80000000h - A001FFFFFh.  

I assure you, there are plenty of machines that use memory mapped
I/O.

-- 
"Worship the Lord your God, and serve him only."  Mat. 4:10
Robert Collins                 UUCP:  ...!sun!altos86!rcollins
HOME:  (408) 225-8002
WORK:  (408) 432-6200 x4356

jca@pnet01.cts.com (John C. Archambeau) (10/17/90)

kaleb@thyme.jpl.nasa.gov (Kaleb Keithley	) writes:
>In article <2056@sixhub.UUCP> davidsen@sixhub.UUCP (bill davidsen) writes:
>>In article <1990Oct10.001733.1299@thyme.jpl.nasa.gov> kaleb@thyme.jpl.nasa.gov (Kaleb Keithley	) writes:
>>
>>| Even if it's an SX.  There's nothing a DX can do that an SX can't.
>>
>>  Whoops! The 16 bit data bus prevents doing 32 bit i/o to memory mapped
>>devices, and the addressing space is only 16 MB.
>>
>
>Got any memory mapped devices in mind?  We are talking about Intel 
>architecture here, not Motorola ;-)  Accuse me of "small world" if you
>want, I haven't seen memory mapped i/o for PC's in ten years, that's
>what the i/o bus is for.  As for memory, yeah, you're right, but how
>many people do you know who are using DOS are being limited by the SX's
>16Meg limit?  I don't know anyone, including UNIX and OS/2 users.  How 
>many people are being limited by DOS's 640K limit?  Everyone.  Remember, 
>not everyone has DesqView/QEMM or Windows 386/3.0
>
>Actually, I think I'll let this whole thread go, since I just upgraded
>my 386SX to a 486 (Can you say $1100?)  Defending my SX from ignorance 
>has become a non-issue to me.  Anyone want to buy a slightly used 386SX 
>w/ 0k, plus an AT case and 200W p/s?  It has run DOS, OS/2, ESIX SysV 
>UNIX, DesqView/QEMM, and Windows 386.  Up to 8 Meg on the M/B, AMI BIOS, 
>C&T chipset.

What I have found is the 386SX is a very viable alternative to going to a true
32-bit machine.  Yes, you are going to have the physical memory and 16-bit bus
limitation, but oh well.  It does do the job nicely.
 
     // JCA

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