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

Mark J. Blair nf6x at nf6x.net
Sun Jan 10 19:55:31 EST 2016


I have a CoCo hard disk system that I got from eBay a while back. The drive would not initially come up happily, but I managed to get it working by readjusting the track 0 sensor vane on the stepper motor, and then I dumped its contents using the MFM Emulator card. I found that the hard drive that came installed is (re)formatted for some old Epson DOS PC clone. I shared the images of the hard drive, floppies that accompanied it, and ROMs on GitHub:

https://github.com/NF6X/CoCoHardDrive

Now I'm trying to reformat this drive for use on the CoCo, and I'm doing it without much documentation. I know it's a long shot, but I hope somebody here knows something about this system.

The system came with a floppy disk controller with Owl-Ware Hard Drive Basic 3 in ROM, a SASI controller cartridge, and a hard drive enclosure containing a Miniscribe 2425M and a Xebec S1410 SASI disk controller. Some very sparse printed documentation and notes came with it, mostly describing how to set it up for use under Basic using a utility disk that doesn't seem to be included, and noting that if it will be used under OS9 then it must be formatted there first, then configured differently for use under Basic. I'm trying to set it up under OS9 Level II v 2.00.01, for which I have original media and manuals, using the software and instructions on the "LRTECH 20 MEG HARD DISK DRIVERS B/U F" floppy that came with the package. It's the one that I imaged as DISK02.IMD in the above GitHub repository.

I've set up my system as follows:

* CoCo 3 w/ 512k
* MPI with CoCo3 mod
* Floppy controller in slot 4
* SASI controller in slot 3 (this is a guess! I have no hardware docs)

I'm following the instructions in the file "LII.addendum" on that disk. I don't have a good way to get a copy of that file onto a modern machine to share here yet, so I'll manually summarize the instructions:

1) Boot OS9 Level II system disk

2) Format a blank disk, which I'll call "HD install disk" here.

3) Put the LRTECH floppy in /d1.

4) Load os9gen

5) chd /d1

6) copy os9boot from system disk to the LRTECH floppy in /d1

7) replace system disk in /d0 with the blank "HD install disk" created above.

8) os9gen /d0 <bootlist.LII
   This does an os9gen with this list of drivers:
   /d1/os9boot (as copied from system disk)
   /d1/CMDS/hd
   /d1/CMDS/hdisk

9) remove LRTECH disk from /d1

10) insert system disk in /d1

11) chx /d1/CMDS; chd /d1

12) using dsave, copu system disk to "HD install disk" in /d0

13) reset to boot from "HD install disk"

14) format /hd

15) (following steps omitted)...


I can get as far as step 14. When I try to format the hard drive, I get an ERROR #245.

Using mdir, I can see that drivers hd and hdisk are loaded, so it seems that the os9gen step did "something".

I know next to nothing about OS9, and I'm feeling a bit stumped at the moment. Can anybody see anything that I'm doing wrong? Maybe I have a hardware problem? Maybe I need different software to do a low level format first? Maybe this Xebec controller and/or SASI cart don't actually work? Maybe I need to use a Y cable instead of an MPI?

-- 
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/



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