Path: utzoo!utgpu!attcan!tls!mbeast
From: mbeast@tls.UUCP (Michael East)
Newsgroups: comp.sys.tandy
Subject: Re: Tandy 6000 Hard drives
Summary: 6000 HD interleave
Keywords: external hard drive replacement
Message-ID: <158@tls.UUCP>
Date: 7 Nov 88 16:01:59 GMT
References: <106@xenlink.UUCP> <12876@ncoast.UUCP>
Organization: Thought Link Systems, Toronto
Lines: 26

In article <12876@ncoast.UUCP>, mikes@ncoast.UUCP (Mike Squires) writes:
> It is my understanding that any ST506 drive with 1024 cylinders or less can
> be used.  The faster the seek, the faster the system.  I added two CMI 6640's
> to a 15MB external system with no mods (except that I rejumpered the 15MB to
> be drive 2 and made one of the 6640's drive 0 - great speed-up).  This worked
> until the 6640's died of old age.  The XENIX formatter allows you to input
> cylinders, heads, and bad tracks; it is apparently possible to play with 
> interleave (I've never done it).  Precomp is fixed and it is possible that
> this might be a problem.  I understand that the 70MB is a Micropolis 1325.

While we are discussing hard drives on the Tandy, I was wondering if anybody
else has played around with the interleave. I did a test last year with 10
different values and had no difference in speed. As near as I can tell the
Z80 combined with the controller always reads in an entire track using the
controller track read instead of retrieving individual sectors. Anybody
know better or can anyone support this theory?

I am interested because I have three different drive types on my 16a and if
I can squeeze any additional speed out of them... need I say more ;-)

Cheers,

----- uunet!attcan!utzoo!tls!mbeast	#include <std.disclaimer>
Michael B. East				(416) 491-6620 ext 508
Senior Technical Analyst		(416) 683-5914 (Home)
Jonas & Erickson Software, Toronto