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Path: utzoo!mnetor!seismo!rutgers!princeton!allegra!ulysses!sfmag!sfsup!perry
From: perry@sfsup.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: SCSI device drivers
Message-ID: <1360@sfsup.UUCP>
Date: Fri, 24-Apr-87 14:50:27 EST
Article-I.D.: sfsup.1360
Posted: Fri Apr 24 14:50:27 1987
Date-Received: Sun, 26-Apr-87 01:10:37 EST
References: <1548@umd5.umd.edu> <1347@sfsup.UUCP> <592@omepd>
Organization: AT&T-IS, Summit N.J. USA
Lines: 60
Summary: SDP Summary

In article <592@omepd>, hah@omepd.UUCP writes:
> Perry, would you please fully describe ASDG's SDP, and when we can expect to
> see it on our dealers shelves and at what price.
> 		Hans

Hans,
	The ASDG SDP series is comprised of four boards:

1.	SDP
	The basic (SCSI only) SDP for the A1000.
2.	SDP/ST
	The basic (SCSI only) SDP for the A1000 with the added capability
	of controlling  two  ST506 devices as well as a full boat of SCSI
	devices.
3.	SDPI
	The same as the SDP but for the A2000.
4.	SDPI/ST
	Same as the SDP/ST but for the A2000.

The term SDP  means:  Smart  (or Satellite) Disk Processor. The controller
contains its own MC68000, a custom MMU, and 512K of on-controller ram.

The controller is  designed  to  support full  bandwidth transfers between
the Amiga and the controller, the controller and SCSI devices, the control-
ler and ST506 devices all in parallel,  all  without interfering with each
other.

The on-card processing power is used to  manage the on-card ram as a large
intelligent buffer cache  (outside the Amiga's  address space) and is used
in intelligent pre-fetching and seek optimization.

Knowledge of the internal  structure  of  the  AmigaDOS file system can be
downloaded from the Amiga providing  compatibility with current and future
file system formats.

Also, should a drive by  partitioned  to contain file systems for co-resi-
dent  operating  systems (like Unix(tm) or MS-DOS(tm)), a facility similar
to the  AT&T File System  Switch  can be employed to download knowledge of
alternate file  system  structures. This is the intended goal of our soft-
ware development effort.

The controller should be available in beta-test quanities late this summer.
Please, we've already  gotten hundreds  of  requests to be considered as a
beta site, we're only sending twenty  or  so controllers out and these are
already accounted for.

We hope to begin mass distribution of the product in the fall.

Note: This is not your  average disk controller. This controller is closer
in design philosophy to main frame disk processors than anything currently
on the Amiga market. As a consequence  we  expect  the performance of this
controller to be far beyond that of any existing Amiga product. We non-the-
less hope to make it available at roughly the same cost less sophisticated
controllers.

Thanks for your interest.

Perry S. Kivolowitz
ASDG Incorporated
(201) 540 - 9670