From: app@shamash.cdc.com ( GSD Advanced Packing/Processes)
Newsgroups: comp.sys.amiga.misc
Subject: Spartan SCSI project problems, Please help!
Date: 13 Apr 92 14:43:24 GMT
Organization: Control Data, Arden Hills, MN


If you are an owner of a Spartan SCSI interface, I would very much like
to hear from you.  

For those who don't know what it is: Spartan is a build it yourself
SCSI interface which was featured recently in the AC TECH magazine.
The article was written by the designer and included in the article
was the software which is the driver for it and a low level
formatter.

I (and four friends) sent away for the PC boards and the controller chips
and purchased the rest of the parts locally.  Total cost was just
under $50.  Unfortunately, none of my friends have built theirs yet and have
not bought their hard drives so I can't swap parts with them. 

Before I go into the problems I'm having, I would first like to state 
that I feel that it is extremely noble of the author (Paul Harker) to 
release his design and software to the public and I do not wish to dissuade 
anyone from doing something similar.  I chose to purchase the PC board and
the controller chip from him but I could have built it on my own
from the information in the article.  I'm sure that the problems that 
I'm experiencing due to apparent incompatabilities with my system were 
unintentional on his part and he has been helpful in trying to help
me figure out the solution.  He even offered to test my board on his 
system to see if there are any shorts or opens on it, since we bought 
five boards from him.  He also promised to send me the source code for
the driver and I'm anxiously awaiting it.

I built two of the interfaces and carefully ohmed out the traces.  I
also probed the signals with an oscilloscope.  I'm absolutley certain
that I haven't made any errors in assembly (I'm a technicion and have
built and tested lots of hardware projects).  Both boards behave the
same way on my system.

The first problem I encountered was in doing the low level format of my
Fujitsu SCSI hard drive.  About nine out of ten times, the low level
format program would complete very quickly and my drive light would
only come on briefley.  The program would not complain about anything and
said the format was succesfull even though it obviously wasn't.
Once in a while it would seem to work and my drive would seem to do the
formatting.  (I tested the drive and my A500 on a friend's Supra
controller so I know it's either the interface hardware or software.)

Fortunately, the source code for the low level format program was
on the disk and I had the scope to help me solve that problem.  I 
recompiled the program and stripped it down so that it was only 
doing one thing while I watched the signals on the scope.  I learned that
I had to put a delay in the routine at a certain place in order for the
formatting to consistantly work (At least I think it's working, all 
I really know is that the drive light comes on for a pretty long time
and the program says its formating and waiting for completion.)

I called the author about the problem and he conceded that he never tried
the software and hardware on a Fujitsu drive and it's possible that there
is a compatibility problem.  For anyone who is considering building
the interface, I would recommend buying a Seagate drive.  Paul said
he tried that drive (and one other but I don't remember the brand)
with his interface.

With this problem apparently solved I tried to do the high level
AmigaDos Format on the drive without success.  I suspect that the
driver program needs a similar delay but I don't as yet have the
source code for it to prove it to myself (Paul said he would send me
a copy to test out the therory but I'm still waiting for it.)

I am not sure that the delay will completley solve my problem though because
the mounting of the driver behaves erratically if I use the mount list
example listed in the article.  My system would crash or report all sorts
of problems (such as "Format failed, can't find handler" or "unable to 
locate DH0").  I discovered that if I removed the last three lines
from the example mountlist, which I believe make use of Workbence 1.3's
FastFileSystem, I get much better results.  The lines removed are:
	GlobVec = -1
	FileSystem = L:FastFileSystem
	DosType = 0x444f5301
	
With this done, at least the driver seems to mount and the AmigaDos
format seems to work to a point.  After formatting I still get a message 
"DH0: not a DOS Disk" when I try to access it.  I'm hoping that if I
add the delay to the driver program, I will at least be able to format
using the slower file system.  

I suspect that there is some sort of bug in the driver that does not
let it use the FastFileSystem and that my configuration brings up
the bug.  The author said he tried it out on his system with
workbench 1.2, 1.3, and 2.0.  Maybe there is some subtle difference
with my configuration that brings out a bug not encountered on his 
system (my words, not his).

My system is an A500 with the 501 memory expansion (1 meg total)
I also have an external disk drive, modem, and printer attached.
I have the 1.3 rom and am using WB1.3 software.

If anyone out there is having similar problems, or no problems at all, 
I would dearly like to hear from you.  I still have great hopes that 
I can get it to work.

Thanks in advance.

					Mike Lundberg
					app@shamsh.cdc.com