[Coco] Re: Floppy drive/OS9 issue

[Andrew]

To all who answered my call for help, thank you.

I didn't know that OS-9 required certain settings to use DSDD drives 
fully, so it very well may be that the OS-9 System image I was using 
wasn't set up in this way. Carey emailed me some other disk images that 
I will try that should be set up for this. My education on OS-9 is very 
limited, but my will to learn isn't. I have 10 years experience (geeze, 
it doesn't seem that long) with Linux, so OS-9 shouldn't be too much of 
an issue (actually, I wish "change directory" wasn't "chd" - I am 
forever typing "cd" from *nix and DOS, and of course it is failing). But 
it will take me a bit to learn - I didn't learn Linux overnight, and I 
don't think OS-9 will be an exception.

Anyhow, in answer to a few things:

- Joel Ewy:

I am looking at the original drive that came out of my FD-501 system 
when I replaced it with the drive from Ebay (the CHINON FZ-502). This 
drive is a TEC FB-501, and it clearly has only the bottom head, not the 
top head. According to my edition of Pocket PCRef, this drive is a SSDD, 
180 kb drive. The drive I replaced it with (the CHINON FZ-502), as well 
as the other drive (TEAC FD-55BR) are both DSDD, 360 kb drives.

I don't know if the original drive is 35 track or 40 track, nor do I 
know if the newer drives are either (the PCRef leaves this information 
out, unfortunately). I suspect the original drive may be 35 track, and 
the newer drives might be 40 track, but that is just a hunch.

- Gene Heskett:

I think you may have misunderstood me slightly - the only thing I am 
changing here, currently, is the drives - that is, I am wanting to add a 
second drive. However, the first one I have I found was a double-sided 
drive, that I thought was single sided (the CHINON FZ-502). When I went 
to add the second drive (the TEAC FD-55BR), I saw it was double sided as 
well. The cable I am currently using came from my original FD-501 disk 
system (which used a TEC FB-501 SSDD drive). I looked at that original 
cable, and I did notice that on both connectors (drive end) that PIN 12 
on the first connector (closest to the end) is missing, and PIN 10 on 
the second connector (closest to the disk controller pak) was missing.

I know that both of my drives, as I have mentioned before, are 360 kb, 
DSDD drives, and not 720 kb or 1.2 mb drives.

I am wondering if on the FD-502 system if the cable, besides being 
straight through, also had the missing pins? Is this what you are 
meaning by "pitch the missing teeth drive connectors in the
trash" - that my original FD-501 cable is part of the issue, too?

I don't see anything like terminating resistors or sockets on either 
drive, though - I know the CHINON didn't have anything that looked like 
jumpers (unless they were SMT solder jumps), while the TEAC has a jumper 
block. I also see on the TEAC a resistor pack (long thin black multi-pin 
soldered-in device, marked "RA1" on the PCB silkscreen), but it isn't 
jumpered (unless by the jumpers marked D0, D1, etc).

I think both drives were for a PC, most likely - and now I am trying get 
them working as real DSDD drives under the CoCo. Would both have 
terminating resistors, and I need to remove one set from the Drive 0/1 
drive, and leave in the ones on the drive for Drive 2/3?

--

I think I have a few old PC cables I could use to pull IDC connectors 
off of, and I have no problem making a cable - but I would personally 
prefer to use new connectors. I have had some "sometimes" bad luck in 
reuse of connectors, sometimes they break on me. I would be willing to 
give it another shot, though - better to try something old than munge a 
new connector, I suppose.

I have no problems with building cables, tweaking config settings, 
desoldering/soldering stuff (though I have no skills in SMT rework) - I 
just want to make sure I am doing the right thing and not mess something 
up worse than it is. I think I could have a really nice system (for 
OS-9) once I get these drives hooked up and working properly.

Something that I am trying to understand, though: Joel, you said that 
RSDOS/Disk BASIC was never updated to use double-sided drives. I could 
have sworn, though, that with the FD502 disk system this was the case? I 
had a friend that had such a system (before I got my FD502 controller to 
replace my bad FD501 controller), and I could have sworn that with the 
drive he had you could put in a double-sided floppy, issue a DRIVE 1 
command, and read/write the other side? Maybe I am just not remembering 
things right? I am wondering if my memory is faulty, or if its a 
hardware/software issue?

I mean, I have a ton of different things here - an FD-502 disk 
controller, connected to an FD-501 cable, running to a likely 
PC-compatible, non-modified DSDD 360k floppy drive. If RSDOS can't see 
the drive as a double-sided drive, no big deal (though that "memory" of 
my friend's system gnaws at me). Maybe under OS-9 it is just a settings 
issue, and perhaps Carey's images will take care of that in short order. 
Even so, I would like to get the other drive installed, with a working 
cable (I realize that I will have to build this myself, but that isn't a 
problem). I don't want to fry either drive with a cable not made 
properly, or with the drives not properly configured (jumpers, 
termination resistors, etc) - or fry the disk controller (it is my only 
working controller). I trust all of you understand my working situation.

I think for now, I will try to get the single floppy drive I have that 
is working, working as a double-sided drive under OS-9 (using carey's 
images and such), unless it is my cable that is also part of the issue. 
Once I am at that point, I can move on to adding the second drive in 
some manner. Until then, any other help anybody can suggest will be 
useful and appreciated, since my knowledge of this hardware and OS-9 is 
not the best currently.

Thank you all again,

-- Andrew