pjm@spuxll.UUCP (PJ Maioriello) (06/05/84)
The purpose of this article is to present a preliminary
review on the MSD disk drive. I have received some mail
asking me to do so. I will attempt to hit most of the
highlights, but I am sure I will miss something that
someone is interested in. If this happpens send mail
and I will attempt to follow up on it.
The statements in this article will essentially be based
on 3 sources; either heresay(magazine adds, rumors etc.),
manufacturors claims (based on conversations with their
technical support people), or my personal experience (hopefully,
the latter will be the most reliable).
To begin with, I have the SD-2 model. This is the dual drive
unit (ala 4040).
To say that I am pleased with it is an incredible understatement.
To put it simply: ITS GREAT. I can copy an entire disk in less
that 2 minutes, including the formatting time (I have timed this at
an actualu 1 min and 57 seconds). Using the copy command to
copy individual files from one disk to another has finally
allowed me to group catagories of programs the way I want.
The first week I had it I must have freed up about 10 disks.
Now for the most important question compatibility;
Most (better than 99%) commercial software will work just
fine. Even disks "protected" by encoding them with errors
will load OK. The supposed reason for why it is so compatible
is that I have heard (catagory 1 above) that the president
of MSD is the guy that designed the VIC 20 for Commodore.
If so he probably knew a lot about the DOS.
The people at MSD told me that they cleaned up a lot of the
code that is in the 1541 which is where they got most of
their internal performance improvements.
Also, I have heard that the 1541 4040 drives are only read compatible.
That is you should not try to write to a disk using one
drive if that disk was formatted with another drive.
When I questioned MSD on that one they agreed with that assesment
and said that they had solved the problem by writing their
sync marks half way between what the 1541 writes and what the 4040
writes, theyeby acheiving read and write compatibility with
both. I dont know enough about drives to even venture a guess
as to wether or not that is a reasonable explanation.
I do know that I use my 1541 and the MSD interchangeably
and couldn't even guess anymore who formatted what.
I have had none of the problems using the MSD 1541 combination
that have been atrributed to a 1541 4040 combination.
The next wonderful thing about the MSD is that it comes with
a built in serial interface AND a built in IEEE interface.
I plan to upgrade to IEEE soon (everyone knows how slow the
standard serial bus is) and the dual interface means that
drive end of the cable is all taken care of.
Mechanically the drive is vastly superior to the 1541. Please dont
take that as a knock on the 1541 because I still use mine and it
was and still is cheaper. It's just that the the extra cost
of the MSD results in a better drive. For instance the housing
is metal (makes it a little noisier, but not objectionally so), and
the drive doesn't clank when formatting a disk or when doing error
retries. There are also seperate LEDs for power, open channel,
and drive operations. The disk seats more positivly and there
is a latch to close not a door. There is also no spring to pop
out the disk (or not pop out the disk when it breaks). There
are slots where your fingers can grab the disk and take it out.
The drive slots are also vertical and not horizontal as in some
of the more expensive floppy drives I have seen.
The SD2 even though it is a dual unit takes up less desk space
than a 1541. The vertical drives help in that regard.
There is also more RAM memory in the MSD. Some of the advertising
even hints at being able to reprogram it to read other disk formats.
It works with Commodore CPM (I have tried this). The SD2
properly uses drive unit 0 as the CPM drive A and unit 1 corresponds
to CPM drive B. Beats geeting the NOW INSERT DISK B message
every time you change the logging disk.
I will venture the personal opeinion here that a C64 equipped
with an IEEE interfaced MSD SD2, CPM, and a compatible 80
column board would be comparable to other native CPM machines
such as KAYPRO. And when you are done with all that real
computer CPM stuff, you can always unplug it all, load up
your favorite game and have some real fun.
If there is anything specific that anyone would like to ask it
might be a good idea to post it so as to generate some
traffic related to alternative hardware for CBM machines.
Given the initally cheap price to get started, I find it
rather interesting to consider the possibilities for giving
something like the 64 more power and greater capabilities
using after market "add ons".
Paul Maioriello
AT&T ISL
spuxll!pjmpjm@spuxll.UUCP (PJ Maioriello) (06/08/84)
OK OK
Sorry I forgot to post the price in my MSD drive review.
To answer that question: The best price I have seen
so far is from RK Enterprises (mail order 1-800-821-1545).
The SD-1 (single drive) is $359, SD-2 (dual drive) is $599.
NOTE: I don't know anything about RK (I brought mine to help out
a friend who ordered 2 SD-2s before he came back to reality) except
that they have the lowest price I have seen so far. I also have
heard the CRAZY EDDIE's (in NJ/NY area) will sell the SD-1.
Old CRAZ says he'll beat any price any time.
To answer Ray MIller's question about head alignment:
First of all my MSD is less than a month old so I can't speak from
experience. My 1541 is well over a year old and it seems to go
through periods of times where it operates flawlessly and then
every once in a while I will notice it perfoming a lot of retries (the
read LED blinks and sometimes the drive clanks).
I can always read my oldedt disks perfectly. My interpretation of
this is that the heads on the 1541 are no longer perfectly aligned,
and are over time becoming increasingly mis-aligned. I have heard
and am fairly convinced that the reason the 1541 suffers from this problem
is that in order to save money CBM did not equip the drive to detect
it's outermost track in any fancy way. Most drives, apparently (I am
not an expert here) use some tome of photo cell or switch to detect
the otermost drive when they do certain operations (like initializations,
error retries, fomatting, etc). The 1541 detects this track by banging
the head against a physical stop. This is the famous "clanking" that is
heard when a disk is formatted or when you get an error. You can
imaginw that a moving head being stopped by a physical obstruction
is probably not conducive to maintaining head alignment. When you
consider how much commercial software is "protected" by error
encoding, it is often a wonder that the heads stay in alignment
as ling as they do. How many "the noise you hear dring loading
is normal" messages have you seen. In constrast (according to the
MSD service people) the MSDs are equipped with some type of
centrifugal switch that detects the outer track. I know from
experience that the MSD does not clank. I now try to use it
exclusively to format disks (beside the fact that it does it much
faster) and to load commercial software that I haven't gotten
around to figure out how to eliminate the stupid error checks yet.
I fully expect this to provide my 1541 with a much longer useful
operating life. If any body else out there has had an MSD
for a longer period of time or can agree with or refute the
above I would be interested in hearing from them.
In summary I dont think that the MSD are going to have any more head
alignment problems that other typical drives that use a decent
method for detecting where the head is. Incidentally, I have
heard that CBM has finally realized this and the 1542 drives
will not use the bang the head method like the 1541 does.
Whew, one more thing, the followup to this article, I dont have
an IEEE interface (yet). I cant directly comment on how they
work or how compatible they are. I don't THINK however that
they will present any problem because that is what all the
other CBM computers (not 64 and VIC 20) use. In fact, the
serial bus was adopted only as a cost cutting measure (what else?)
with the introduction of the VIC 20. Prior to that CBM had
always used the IEEE standard. That's why I dont think that
there will be any big problems. Also I tried running a CPM
system generated to run on a 44k C64 IEEE system using my
MSD drive on the SERIAL bus and it worked!! It seems
as if the kernal routines don't really care all that much
wether you are hanging off an IEEE bus or the built in serial
bus. Perhaps Ray can verify this.
A friend has just gotten a Batteries Included IEEE bus card
that has some very interesting features. When I learn more
I will post another articles. My typing fingers are
getting awfully tired.
Paul Maioriello
AT&T ISL
spuxll!pjm