[Coco] Formatting L.R. Tech Hard Drive in OS9 Level II

David Gettle david17361 at gmail.com
Wed Jan 13 14:47:26 EST 2016


I had one of the LRTech/Owlware systems, formatting the hard drive only
needs the OS-9 format command (same command used to format floppies). The
trick is to get the head/sector count correct for the drive. the LRTech
hardware and OS-9 drivers address the disk in 256 bite sectors, so a 40MB
hard drive does actually format out to nearly 40 MB. Dmode is your friend!
you NEED Dmode to adjust the heads, cylinders, and sector count for the HD,
also you will need to create a HX.dd for the second drive. it's a lot of
trial and error to get those set up correctly. the only hard drive
descriptor you should not format is /dd.

Most floppy systems sold after the intro of the CoCo2 were DSDD because
OS-9 could use DSDD floppy drives and RadioShack didn't want to bother with
two different drive types for the CoCo and IBM Clones.

On Tue, Jan 12, 2016 at 10:15 AM, Barry Nelson <
Barry.Nelson at amobiledevice.com> wrote:

> In an earlier post I described how you can adapt a 28 pin EPROM to a 24
> pin socket. I was running like this before I got my CoCoSDC cartridge. I
> used a larger EPROM and attached a switch to the extra address line to
> select either HDBDOS or RSDOS.
>
> >        Mark J. Blair nf6x at nf6x.net  <mailto:coco%40maltedmedia.com
> ?Subject=Re%3A%20%5BCoco%5D%20Formatting%20L.R.%20Tech%20Hard%20Drive%20in%20OS9%20Level%20II&In-Reply-To=%3C317189F9-DBD1-4149-AF70-1ED1AE894416%
> 40nf6x.net%3E>
> Tue Jan 12 02:00:18 EST 2016
>
>
>
> Ø  On Jan 11, 2016, at 22:34, Barry Nelson <barry.nelson at
> amobiledevice.com <https://pairlist5.pair.net/mailman/listinfo/coco> >
> wrote:
>
> >         >
> Ø  I have seen several Radio Shack drives that were in fact double sided.
> They did this because they used the same drives in their IBM compatibles.
>
> >         Interesting!
>
> >         Both drives in this FD-500 (one original, and another mismatched
> on that I added myself) are single sided, but I'll put my dual Teac FD-55B
> drive box back together. I had borrowed one of its drives for the ImageDisk
> PC.
>
> >         I might either load up HDB-DOS from cassette as suggested, or
> burn an EPROM and temporarily swap it in place of the Owl Basic EPROM in
> the floppy controller that came with this hard drive system.
>
> >         I wouldn't mind getting my hands on another CoCo FDC cart with a
> 28 pin EPROM socket to dedicate to HDB-DOS, since that might be convenient
> to have on hand. I think that all of my other FDC carts have 24-pin sockets
> with the mask ROM pinout, and I don't have any of the pin-compatible EPROMs
> on hand. If anybody has one to sell or trade, please drop me a line. I'd
> love to add a JFD-CP to my collection, but one of the other FDC carts that
> were made with 28 pin EPROM sockets would also be useful.
>
> >         --
> >         Mark J. Blair, NF6X <nf6x at nf6x.net <
> https://pairlist5.pair.net/mailman/listinfo/coco> >
> >         http://www.nf6x.net/
>
>
>
>
> --
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>


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