Path: utzoo!attcan!uunet!aplcen!uakari.primate.wisc.edu!dogie.macc.wisc.edu!uwvax!cleo!mt
From: mt@cleo.cs.wisc.EDU (Manolis Tsangaris)
Newsgroups: comp.sys.mac.hardware
Subject: Re: [comp.sys.mac.hardware] Adaptec 4010 SCSI<==>ST506
Message-ID: <9793@spool.cs.wisc.edu>
Date: 20 Feb 90 18:13:25 GMT
References: <11041@stag.math.lsa.umich.edu>
Sender: news@spool.cs.wisc.edu
Reply-To: mt@cs.wisc.edu
Organization: University of Wisconsin, CS department
Lines: 38

In article <11041@stag.math.lsa.umich.edu>, cspencer@spdcc.COM (Cliff
Spencer) writes:
> ......
> I am familiar with Adaptec's ACB 4000 from Suns. This board lets
> you hook PC disks up to a SCSI interface. I have a sheet from a 
> surplus store advertising  the ACB 4010 as a similar board for the
> Mac. Does anyoe have any experience with it?

Yes I do. I have a system with a 30Mbyte Miniscribe and an Adaptec 4010
ST506<->SCSI controller. The disk was formatted using a public domain
program called SF&I (available from sumex.stanford.edu).

The driver implements a good subset of the SCSI commands, and it works
satisfactory. In terms of transfer speed, SCSI evaluator gives a very low
figure (something like 6-10Kbytes/sec!), even though :

* the controller does track buffering
* I use the highest possible clock for the transfers, and
* the interleave factor is 1:1.

Maybe the poor old 8085 of the controller is not fast enough,
or most likely the driver does not do its job efficiently.
Blind SCSI tests (that I thing bypass the driver) do not work correctly
on the MAC (MAC II, System V.6.0.4).

A major problem of the driver/formatter, is that it does not support
partitioning, and the use of a second drive (The 4010 supports two
ST 506 drives that show up as Logical UNits 0 and 1). 
Additionally it does not include any sources.
The MAC system software does not seem to have a notion of LUN's, so you must
cheat it by presenting the two disks as (at least) two partitions.

A public domain driver from Leo Drizis (March 1989) could be a good
start for an effort like this.

Now, why ACB 4000(A) would not work on a Macintosh?

--mt