Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!asuvax!mcdphx!teroach.UUCP!stan
From: stan@teroach.UUCP (Stan Fisher)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: SetCPU and the 2091
Keywords: SetCPU, 2091
Message-ID: <12603@mcdphx.phx.mcd.mot.com>
Date: 12 Mar 90 17:23:44 GMT
References: <11051@june.cs.washington.edu>
Sender: listen@mcdphx.phx.mcd.mot.com
Reply-To: stan@teroach.UUCP (Stan Fisher)
Organization: Motorola Microcomputer Division, Tempe, Az.
Lines: 42

In article <11051@june.cs.washington.edu> dylan@june.cs.washington.edu (Dylan McNamee) writes:
>
>Thanks to many people on the net, here is a SetCPU file entry for using 
>CardROM option with the 2091:
>
>0x202 0x03 0x10000 0x2000 0x3FFF CBM_2091_SCSI_Controller
>
>These are, in order, Manufacturer, Product (may be 0x02, use Dave Haynie's
>CacheCard Program to check,) Card size, Base Address of ROM, size of ROM.
>
>I found the size of the ROM by guessing and checking.  The system crashed
>when I was wrong.  Be sure to use the verbose option of setcpu, to be sure
>your file was accepted, and always use the cardrom option along with the
>Fastrom option.
>
>Now for the wierd part;  I'm not getting _any_ performance improvement.
>It's about 382K/sec Reads, and 335K/sec Writes (32KBits at a time) using
>DiskSpeed.  Has anyone had any better luck?  About what should I be getting?
>Anyone?  Anyone?
>
>dylan mcnamee
>dylan@cs.washington.edu


GREAT!! thanks for the CardROM line, I was about 95% of the way to the
same goal myself.

As far as performance improvements, I'll quote Joe Augenbraun (designed
2091/590 hardware), (actually paraphrase) 
"Don't expect faster disk access BUT more idle CPU time for other tasks to
use during disk transfers." 

I had had the same thoughts initially, until I talked to Joe.
Having the code in 32 bit ram will give the rest of the system more
processor use during heavy disk accesses, since the 2091 is DMA.

Did I get that right Joe?


  Stan Fisher -  stan@teroach.phx.mcd.mot.com -  asuvax!mcdphx!teroach!stan
  Motorola Microcomputer Division, Tempe, Arizona   -  Voice (602) 438-3228
  Call our User Group BBS "M.E.C.C.A." running Atredes 1.1 @ (602) 893-0804