🚀 go-pugleaf

In article <1992Sep10.034104.9879@nuscc.nus.sg> eletanjm@nuscc.nus.sg (TAN JIN MENG) writes:
>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:
[...]
>
>On the other hand, EISA motherboards (in my country) cost about US$500
>more only. Plus you can upgrade to EISA peripherals incrementally.

Gee "ONLY" a half grand.  Ahem.  Also forget anything but an EISA HD
controller on an EISA M/B for anything but DOS.

>
>: 
>:   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.

Not much real difference there either.  Most people don't buy SCSI-II
disk arrays and such so the bus is not really a bottleneck.  Expect to
see onboard graphics stuff soon, and local bus for video, *OR* video
coprocessor cards (My clone Distributor sells 2 now for Windows) that
will again reduce the ISA bus bottleneck's significance.

>
>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!
>

Nah, OS/2 is just broken in this respect then.  SCO & I beleive SVR4
reserve RAM <16MB for ISA DMA and copy up if need be.  Pretty simple
concept here IMHO.  Then you can CRAM as much RAM as you want in the box
and still use ISA controllers.  Again,  The bottlenecks aren't the BUS,
but generally the DISKS themselves.

>: 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
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