🚀 go-pugleaf

davidsen@ariel.crd.GE.COM (william E Davidsen) writes:
: In article <14409@goanna.cs.rmit.oz.au>, s923257@yallara.cs.rmit.OZ.AU (Chew Ming Ean) writes:
: | Is the 486 a 32 bit bus computer????
: | 
: | If so what is the difference between the busses?? ISA and EISA???
: | 
: | Will it make a lot of difference if I purchase the ISA instead of the EISA
: | bus???
: 
:   No. The memory on a 486 (all the ones I've ever seen) is one the
: motherboard, and that's the primary bottleneck. Going to EISA will get
: you some extra performance with video and disk if you use pricy
: controllers, but it's not a huge difference, and unless you have a need
: for the ultimate speed in video and disk I wouldn't consider it.

On the other hand, EISA motherboards (in my country) cost about US$500
more only. Plus you can upgrade to EISA peripherals incrementally.

: 
:   I use both ISA and EISA, and EISA config is a royal pain in the ...
: ear. Under normal single user load, and particularly with DOS, you will
: be able to measure the boost, but probably not feel it.

Yep. With DOS - not much diff in the normal case. One the other hand,
OS/2 and NT (and Solaris , and NextStep) are coming up. You might want
to get a [real man's OS ;-)] capable machine.

One of the very real limitations regards these 32bit OSes that has been
exposed by OS/2 is the 16MB physical addressing limitation of the ISA
bus. ie. the DMA controllers can only access up to 16MB of physical
memory. OS/2 on [most] ISA machines therefore uses only the bottom 16MB
for process memory and any memory above that for page cache!

: 
: -- 
: bill davidsen, GE Corp. R&D Center; Box 8; Schenectady NY 12345
:     I admit that when I was in school I wrote COBOL. But I didn't compile.

jin meng