rick@ut-ngp.UTEXAS (Rick Watson) (08/27/85)
[bug food.]
Here's a preliminary report on the Macintosh SASI/SCSI interface made by
Fastime.
I mailed a check for $150 about a month ago. The interface arrived last
Thursday. For $150 you get: the interface board, a disk with some software,
and some printed documentation.
The board consists of a NCR SASI/SCSI bus controller chip, a couple of 7400
series gate chips, some resistor packs, some feed-thru sockets, and a 50-pin
connector. The board is aprox 2 and a half inches square (rough guess.)
To install it, you remove the roms from the mac, plug in the board where
the roms were, and plug the roms into the board. There is a one wire chip
clip that you are supposed to clip to a lead on a nearby chip. I didn't like
the chip clip, so I cut it off and soldered the wire where it was supposed to
go. The only difficult part of the installation (beyond getting the Mac apart)
is putting the logic board back in the Mac. The 50-pin connector sticks up a
bit too far and you have to wedge things a bit. Then you plug in your 50-pin
cable. I was able to run the 50-pin cable out of the back of the Mac beside
the battery case. I cannot put the cover back on the battery case, but
since my Mac is still under AppleCare, I don't want to hack the case. I could
at this point remove the board and make it look like the board was never there.
You then plug the other end of your cable into a SASI/SCSI disk controller, and
presuming you have that connected to a disk and power supply, you are ready to
go. I am using a Xebec S1410A hard disk controller and a Shugart 604 5-mb
winchester disk.
The software that comes with the kit supports the S1410/Shugart combination,
so I didn't have to make any changes. The software includes the sources for
a disk formatter and the driver for the Mac. Also there is a driver install
program. Sources are Aztec C. Some of the C includes assembler, so conversion
to other C is not as easy as one would like. I know that Megamax C supports
in-line assembler, but not the same. The formatter and driver are also already
built. The driver install program was supposed to be there, but was not.
It took me about half an hour to build a driver install program using
Megamax C. It is a very short program, but the calling parameters for
OpenDriver are different between Aztec and Megamax C. My program kept
crashing until I stopped to look at InsideMac.
Once you are hooked up, you run the format program. Be sure your Xebec is
jumpered for 512 byte sectors. BE CAREFUL with the format program. It does
not bother to ask you if you want to format the disk.
After the disk is formatted, you run the driver install program. When you
return to the Finder, there is the hard disk with a little over 5000K free!!!
The driver install program does not bother to make the hard disk the startup
disk and eject the boot floppy as I would like. At this point, you can
copy the System and Finder to the hard disk. Then you command-option-double-
click the Finder on the hard disk to make it the startup disk. Then, you
copy ALL your favorite files to the hard disk.
The driver supports a non-partitioned disk. There is supposed to be
a new software release "soon" that supports some kind of partitioning.
The software works great as long as you don't have any disk problems.
This version does not appear to check for disk errors. I had some problems with
this as I had a bad sector in the directory. Hopefully, the next version
of their software will correct this. The price list I got with the kit
says the upgrade will be available 8-15-85 (yes, < today) and costs $20.
I hope they don't really expect me to pay for this. The lady I talked
to on the phone today didn't know anything about the new software, but
promised to call me back.
The hard disk works quite well (barring disk errors). Very rough timings
put it at about the speed of a Hyperdrive, but I didn't have very good
times for the Hyperdrive. I have about 130 files on the disk now and
launching the finder (4.1 from the desktop) takes about 9 seconds.
This compares to 15 seconds for a floppy with 30 files and even longer
for 2 floppies. Other things like edit/compile and simply exit to finder are
much faster, and it is really great to have 1 disk with plenty of room
instead of squeezing onto 2 floppies. I have a program
that writes 512 bytes to the controller, and reads it back. It will do
1000 passes in 16 seconds, so I am getting 500,000 bits/sec including
all the overhead. Note: this is reading/writing the controller ram, not the
disk.
Overall, I am very pleased. The software could use some work. It needs:
1. Error detection. The XEBEC does retries, but if there is a bad spot,
there is just no way for the controller to recover.
2. A mount program that makes the hard disk the startup volume and ejects
the startup floppy (a la RamStart).
3. Disk partitioning (promised).
4. Multi-drive support (might come with partitioning). The XEBEC will
suport 2 drives.
5. A hard disk backup program.
This is what my system cost:
1. Fastime interface $150
2. XEBEC S1410A (from Kieruff) $165
(Paramount carries S1410's for $125. They could not
tell me over the phone if they were S1410A's. I
use the S1410A because I have them in other equipment.
Either should work with this software.)
3. Shugart 604 from Priority I (5 mb) $ 99
4. Cables, power supply. ~$ 60
You need to be a moderately good hardware hacker to go this way. Their
documentation is pretty terse. You also get schematics in MacDraw
format on the software disk. You even get a schematic for their
next product -- a SASI/SCSI controller plus some parallel ports.
They also sell kits that include the disk controller and hard disk.
I would be interested in anyone else using this product. I have written
some quick and dirty utilities to dump error stats out of the Xebec, and
read all the sectors on the disk. You can use Fedit to put any bad
sectors into a file. My directory sector problem went away after I
re-wrote it. I will be doing some more work if their next
software release does not have everything I want.
You can order from:
Fastime
p.o. box 12508
San Luis Obispo, CA 93406
(805) 546-9141
Basic Mac SCSI Host Adapter Kit $150.
UPS shipping $5.00. UPS COD $10.00
I have no connection with Fastime or DMS design. This is a home project
not supported by where I work.
----------------
Rick Watson
University of Texas Computation Center
Austin, Tx 78713
(512) 471-3241
rick@ngp.UTEXAS.EDU rick@ut-ngp.arpa
...ut-sally!ut-ngp!rick