riscy
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Re: Mips on vesa

To: riscy@pyramid.com
Subject: Re: Mips on vesa
From: Drew Eckhardt <drew@ophelia.cs.Colorado.EDU>
Date: Mon, 26 Jul 1993 01:56:06 -0600
In-reply-to: Your message of "Sun, 25 Jul 1993 04:36:15 CDT." <9307250837.AA10151@gossip.pyramid.com>
Reply-to: riscy@pyramid.com
Sender: owner-riscy@pyramid.com
    The original mips design seemed to be basically mips+simm slots 

Plus cheap onboard SCSI, serial ports, video, and perhaps ethernet.
    
    on ISA bus and

Not on an ISA bus, but with an ISA bus for people who insist on 
having PC-compatable expansion slots. 

    seems to have been dropped because of ISA limitations and board space.

IMHO, it seems to have been postponed because of

1. No suitable DMA/DRAM/peripherial controller is available - 
        the 3730 isn't shipping and the Visual MOM chipset lacks 
        support for slave mode DMA. (Has anyone looked at the 
        NEC chipset?)

2.  The 4200 would be faster, and should be cheaper than the 
        3081.  Availability at this point is questionable.$

3.  In 6-9 months, IDT ships the Orion, an R4000 compatable chip.
        Also faster and cheaper than the 3081.

    How about one simpler.  Just a mips chip (whatever we can afford)+cache 
    on a vesa card.  

It depends on what our goals are. IMHO, we need to clearly define what these
are before getting furthur into the technical aspects of things.

    As I understand it VESA is basically the pc memory bus.
    
    Running on the VESA bus at 25-33 Mhz will give you 100-128 MB/sec bandwdith
    to memory, this makes a local cache important but seems workable.
    
    Everything would be reused.  People could buy the ISE/VESA card of there ch
   oice.
    A 486/25 sx is $215 or so would be used as a host.

For the people who want a "workstation", the motherboard solution
wins hands down.

+ $200 SCSI (You can't buy large IDE drives at any price)
+ $200 video (VRAM based local bus)
+ $50 16550 serial board
+ ethernet ???

Total : $615 + ???

Compared to a motherboard solution of 

+ $90 main board
+ $25 SCSI
+ $20 (serial ports, either one of the integrated chips or a 16552)
+ $100 video (1M, VRAM based (ie, 1152x900x256) $60 for 2M )
+ ethernet ???

Total : $235 + ???


 

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