Microbyte Floppy Disk Drive
Paradox Enterprises, Inc.
Version A, 360K Nth $235
Version B, 1.2MB Nth $245
by Matthew J.W. Ratcliff
The Microbyte 5-1/4-inch floppy disk drive for the Atari ST is an extremely useful device to own—if you need one. If you have an IBM at work, or a PC at home, you'll probably want, if not need, this drive. (I tested the 360K version for this review.)
We know ST cannot run IBM programs (at least, not without an emulator), so what use is this drive? Let me give you a few examples. If you use Generic CADD at work, you might like to bring your designs home and use First CADD on those same files. (These programs don't use the same format, but are written by the same software house. The ST version of First CADD comes with a utility for performing the necessary conversions). A similar argument holds true for Lotus and VIP Professional, which are file compatible.
Moreover, if you write a lot, it's always convenient to be able to easily move text files between the two machines. I occasionally develop code for work at home, and vice versa (on my lunch breaks or course), so I've really had a chance to put the Microbyte through its paces. Currently, 5-1/4-inch floppies cost about one-fourth as much as the 3-1/2-inch diskettes, so the Microbyte is handy for archiving a lot of files economically.
The drive comes in a sturdy metal case (color matched to the ST system), and is a half-height mechanism, just like the current crop of DS/DD drives found in IBM PC XT compatibles. This unit employs the same power supply as Atari's 8-bit 1050 disk drive: a simple 9-volt AC output transformer (easily replaced).
Of course, it's as simple to hook up as any other ST drive. The interface cable is hard-wired into the drive, with a male connector for the computer or the other drive at the opposite end.
There's no output connector on this unit. This means that the Microbyte is drive B if you have a two-drive system. If you wish to use it as drive A, you cannot have a second floppy on the ST.
The connector is a bit oversized. Although I had no problem daisy chaining it to my old SF354 Atari drive, when I upgraded to the newer SF314, I found it very difficult to get the Microbyte connector to stay in place. Careful arrangement of the cables solved the problem.
Once the drive is hooked up to the ST, the busy light comes on and stays on while the computer is booting. When the system is up, and all is well with the Microbyte, the busy light pulsates dimly, like a heart beat, to let you know everything's A-okay with the unit.
Two programs come with the drive. The Paradox program must run from an auto folder at boot time, which sets a different step rate for the Microbyte drive. The head access time is slower for a 5-1/4-inch unit than than the 3-1/2-inch floppies normally used. If the step rate is not set properly, you'll get constant read and write errors.
The second program is a format utility, used to perform a double-sided, double-density 360K format of the 5-1/4-inch drive. (The 360K formatting we normally do is for a single-sided 3-1/2-inch unit; it just won't work for a 5-1/4-inch drive.) The biggest problem with this formatting utility is that disks prepared with it cannot be read on an IBM PC or compatible. This is frustrating because you must format all your 5-1/4-inch disks on the PC, if porting files is your primary goal. (A disk formatted on the PC can be read and written on either computer.)
The formatting program provided by Paradox writes all zeros to the empty sectors, as does the GEM format utility. However, the IBM expects to see the following bytes (this information courtesy of Joe Pierce, Delphi user-name JOEPIERCE), in the first four positions of track zero, sector zero:
PS7 FT6 $EB, $2C, $90, $49
If those bytes are not there, the IBM assumes the disk is blank, or damaged. When Joe gave me this data, I took an ST formatted 5-1/4-inch disk to work and used a disk editor to write those bytes out there. After the modification, the IBM no longer thought the disk was blank, but could read and write to the disk with no problems.
Paradox definitely needs to update its formatter with this information. I would prefer an accessory version of the format utility, so a 5-1/4-inch disk can be formatted from a desktop menu, like the 3-1/2-inch disks.
Because of the unique format of a 5-1/4-inch disk, none of the hard drive backup utilities will work with the Microbyte, which, of course, is one of the uses I had planned for it. I have been archiving some valuable folders from the hard drive "by file" to the 5-1/4-inch disks with no problems, however. A hard drive backup utility, specifically written for the Microbyte drive, would certainly be useful.
One particular annoyance you will encounter with this drive is that the power switch is at the rear, making it difficult to access if you have a computer hutch or similar setup. You will also find it necessary to shut it off from time to time with certain commercial software. Some programs (World Championship Karate, for instance) detect the presence of a second drive. If they find one, they automatically expect a data disk to be there.
After several months of daily use, I've found the Microbyte to be a quiet, fast and reliable little workhorse. It comes in handy for proting files and making inexpensive backups of my files, and most important, keeping the clutter off my hard drive.