Re: RQDX3 software interleave

I guess I should have sat down and thought about it, I never even considered the hardware doing software interleave (quite a dumb thing to do, IMHO, unless you want to sell preformatted diskettes for use in systems with widely varying performance characteristics; who would want to do that :). Thanks, Herr Ivie, for that insight. Also thanks to SMS for the disklabel enlightenment. I should have a workable solution soon, though doing the interleave code in 4.4BSD kernelland doesn't seem like much fun and would reduce the general applicability of the driver (I'd like to see what the FreeBSD committers would think when I suggest _that_!); I think I'll just write an "interleave filter" in userland and leave it at that. write Don't get me wrong, I _am_ happy. I like smart hardware as long as it doesn't try to second-guess me; I'm a big fan of SCSI. Just a natural and (usually, but not always) healty curiousity. And I know how much fun floppy drivers are to write; one of the products developed by my employer (though before I was thus employed) was a disk conversion system. And we even used one of the more "intelligent" floppy controllers, an experimental TI 9909 that handled "pretty much everything" for you (as long as "pretty much everything" involved writing single-density IBM 8" diskettes -- reminds me of the line in Raising Arizona, when N. Cage asks the cashier if he has balloons in funny shapes and he replies: "if you think a circle is a funny shape"). So I have the source code to a floppy driver that handles almost any disk type imaginable (as long as the data rate isn't too high: 2.88MB disks zum beispiel), all written in assembler and PLM for an 8085; talk about tight code. Speaking of PITA device control, wasn't it the DEC RX02 that wrote address information in single density and data in DD? Once again, thanks for everyone for all the help. I'll have this thing working soon. -jtm Received: (from major@localhost) by minnie.cs.adfa.edu.au (8.9.3/8.9.3) id GAA23073 for pups-liszt; Thu, 8 Jun 2000 06:56:27 +1000 (EST) (envelope-from owner-pups(a)minnie.cs.adfa.edu.au) Received: from ns1.teraglobal.com (ns1.teraglobal.com [63.210.171.3]) by minnie.cs.adfa.edu.au (8.9.3/8.9.3) with ESMTP id GAA23069 for <pups(a)minnie.cs.adfa.edu.au>; Thu, 8 Jun 2000 06:56:24 +1000 (EST) (envelope-from rivie(a)teraglobal.com) Received: from [10.10.50.26] (208.186.13.23) by ns1.teraglobal.com with ESMTP (Eudora Internet Mail Server 2.2.2); Wed, 7 Jun 2000 13:54:07 -0700 Mime-Version: 1.0 X-Sender: rivie(a)ns1.teraglobal.com Message-Id: <v04210100b564661bc3fe(a)[10.10.50.26]> In-Reply-To: <Pine.LNX.4.10.10006071443590.6772-100000(a)guildenstern.shaffstall.com> References: <Pine.LNX.4.10.10006071443590.6772-100000(a)guildenstern.shaffstall.com> Date: Wed, 7 Jun 2000 14:54:01 -0600 To: pups(a)minnie.cs.adfa.edu.au From: Roger Ivie <rivie(a)teraglobal.com> Subject: Re: RQDX3 software interleave Content-Type: text/plain; charset="us-ascii" ; format="flowed" Sender: owner-pups(a)minnie.cs.adfa.edu.au Precedence: bulk Yes, it was. But it was usually done by the hardware (I suppose that would be microcode in the case of the RX02), so unless you wanted to do something foolish like read RX02 diskettes in your DD CP/M machine or format floppies you don't have to worry about it. -- Roger Ivie rivie(a)teraglobal.com Not speaking for TeraGlobal Communications Corporation Received: (from major@localhost) by minnie.cs.adfa.edu.au (8.9.3/8.9.3) id HAA23245 for pups-liszt; Thu, 8 Jun 2000 07:38:22 +1000 (EST) (envelope-from owner-pups(a)minnie.cs.adfa.edu.au)