In the early 1980s the MSD SD-2 Super Disk Drive was one of a series of 5 1/4” floppy disk drives made by Micro Systems Development (or MSD) in Dallas, Texas.
For some, the MSD SD-2 is considered one of the holy grails of Commodore-compatible 8-bit drives and early 3rd-party hardware. Released in 1983, supposedly MSD’s drives have the notable distinction of being the first third-party devices designed to be used with the Commodore 64.
There were two models: the SD-1, which was a single-drive unit. And the top-end SD-2, which we’re looking at today.
Being so early in the C64’s lifespan, MSD decided the Super Disk Drives would include both an IEEE-488 parallel interface as well as dual custom Commodore serial interfaces. This means the MSD drives are plug-and-play and ready to go not just with the VIC-20, C64 and C128, but also the Commodore PET without the need of any special adapters.
However, with the addition of MSD's optional and custom IEEE interface for Commodore 64, which plugged into the expansion port, users could obtain enormous transfer speed gains over the 1541 on the Commodore 64 and 128 computers. A similar adapter called the IEC64W is around today and much easier to find brand new…
- Note the IEEE-488 port!
These drives were popular in the 1980’s due to their impressive speeds but even more so due to their incredible disk-copying capabilities, which we’ll look at a bit more here in a minute.
When the drives were introduced, they cost more than Commodore’s 1541 drive. The SD-1 single drive could be found in 1985 via mail-order for $249 compared to $199 for a 1541. The SD-2 was listed from $449-$675 depending on the source, however this was at least less than the Commodore PET 4040 dual drive, which sold for a staggering $699 (equivalent to almost $2,000 in today’s dollars).
Design
Right off the bat, the MSD SD-2 was the only dual drive option out there for the VIC-20 and beyond. Commodore had eventually drawn up a dual-drive prototype in the mid-80s called the 1572, but it was never brought to market.
- A long time ago a prototype of the 1572 was shown where the drives were side-by-side, fitting perfectly on top of a C128D. But in this illustration, they are stacked vertically. This book was obviously published before realizing the product had been cancelling.
The MSD drives were built like tanks with professionally painted solid metal cases instead of plastic.
And these drives are as heavy as bricks - bricks made of metal! In fact, my MSD SD-2 super-heavyweight “George Foreman” drive tops the scales at a whopping 14 pounds 2 ounces!
Features & Operation
The MSD SD-2 came with its own microprocessor and memory. It included a 16K operating system and 6K RAM buffer (only 4K came on the SD-1). It has a microprocessor-based disk controller, dual commodore serial bus interfaces, an IEEE parallel bus interface, and internal jumpers to select the device number.
The C64 came with BASIC 2. The C128 came with Basic 7. The MSD drives came with BASIC 4. Therefore, there are some BASIC commands you can perform from disk to disk with the SD-2 you can’t even perform between two 1541’s - like the COPY command.
Due to the differences with the on-board DOS, incompatibilities are a thing. Commercial disks that use certain types of copy protection, fast loaders or 1541-specific features do not work with the MSD Super Disk drives.
However, the MSD SD-2 is capable of being upgraded with JiffyDOS, as well as 3rd-party ROMs called the CLD Disk Duplicator, which transform the SD-2 into the ultimate Copy Party Battle Station.
The SD-2 can already copy quickly from one disk to another, but it can be converted into a professional disk cloning device, too. Ironically, you may need to actually load and run that copied floppy on a different drive later, though.
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The SD-2 consists of a PSU, a controller board and the two TEC 360K PC floppy drive mechanisms. They were modified by MSD to be compatible with the GCR recording format used by all Commodore floppy disk drives at that time.
And like a lot of old tech, the caps on these ancient drives are notorious for leaking.
My SD-2 needed work when I got it in 2022. Both of my drive mechanisms in the TEC FB-501 drives needed to be re-worked; all polarized electrolyte capacitors on both analog boards and both spindle drive boards needed replacing. And the smaller electrolytic capacitors on the main board also needed to be replaced.
When I received my SD-2 I located a very skilled technician in Maine, USA, who is an expert in MSD drives . If anyone has an old MSD in need of repairs or restoration, feel free to contact me and I’ll pass along his info.
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Interestingly - at least to me - my SD-2 has a professionally installed selector switch on the back that changes the drives from 8 to 9. The original owner of my drive was in Texas, and it makes me wonder if he got this fancy upgrade from the source in Dallas. The case looks to have had its switch hole punched out by the factory with a really slick switch added - not the typical long metal things hanging out the vents from a dangling wire or some other janky but functional DIY hack.
You might be wondering: “There are dual drives, so how does this switch selector even work?” It’s actually pretty interesting.
Usage
The SD-2 is seen as 2 drives under a single device ID Number. You can set both drives to either 8, or 9. You can’t, however, set one of the drives to 8 and the other to 9.
The SD-2 powers up in a DRIVE 0 & DRIVE 1 configuration where both are seen as device ID 8 or 9.
Drive 0 is the drive on the left, and Drive 1 is the one on the right.
Naturally, the syntax is a little different than we are used to. For example, in order to examine the directory of a diskette, the syntax is:
Code: Select all
LOAD "$0",8To load the directory of a disk in Drive 1, I would need to type
Code: Select all
LOAD "$1”,8See what we did there? The drives aren’t 8 and 9, they are 8-0 and 8-1.
If no drive number is specified after the $, both directories will be loaded into the computer.
To use our common LOADSTAR command, on the SD-2 it would be
Code: Select all
LOAD "0:*",8So, yeah, some different syntax to learn here with common commands if the SD-2 is to be used like regular floppy drives, which is described in detail in the user manual.
Technically, it’s also possible to change the jumper selections inside the case to make them 10 and 11 if we wanted to, or via software.
Additionally, the SD-2 really shines when used with the rare software title which recognizes a dual drive, such as Calc Result Advanced.
CLD Mass Duplicator
One of the most fascinating and frankly kick-ass features of the MSD SD-2 is the ability convert the machine into a stand-alone “Mass Duplicator.”
Since the MSD Super Disk Drive uses its own CPU and DOS, it can format disks in a stunning 9 seconds. You can even format 2 disks simultaneously in the same amount of time.
It can backup a disk in a shocking 15 seconds - including verification.
There are also Nibbler programs for copy-protected disks.
But by swapping out the original ROMs with Chip Level Designs (CLD) Mass Duplicator ROMs and installing a RAM chip upgrade, the machine can copy unprotected disks all by itself. With this upgrade, you don’t even need a computer! The drive will automatically detect disks being inserted and removed.”
To my joy and surprise, I discovered my SD-2 already had the RAM upgrade installed. I have no idea why the previous owner would have done that. It’s possible MSD provided that upgrade as a form of future-proofing, or possibly it provides a mild speed boost in normal operating mode. I really don’t know. I also don’t know how this beast got the absolutely pro ID switch.
Regardless, my machine only needed the U5 and U6 ROMs to be swapped out to become a “Mass Duplicator.”
[TEXT-ONLY] Fun fact: in the original manual they show folks how to install the ROMs - by pressing them into the PCB and bending the legs over with a screwdriver!
In all honesty, I love this. If it worked, it sure saved a lot of time and equipment. However… if it didn’t, you just bent the crap out of all those legs! (And in that case they recommend soldering. Hah!)
Anyway, with the new ROMs my SD-2 is now a stand-alone Disk Duplicator with no computer required. When we insert 2 disks and close both latches, it just starts cloning a disk all on its own and can be completely untethered from any computer or monitor. And, it does it really fast!
Once you install the new ROMs, you do a quick chip test.
Type: LOAD"CHIP TEST",8,1 and hit RETURN
Copying
The green POWER light will blink and the drive will make a faint ‘clicking’ sound as it awaits the disks. As each disk is inserted, the red DRIVE 0 & 1 lights will come on. When it has finished the backup, the POWER light will blink again. Remove both disks and repeat the process.
- When I took this photo, the drive was in the process of auto-copying the disk in Drive 0 to Drive 1, and only plugged into power. No computer, no nada.
There is also an Auto Nibbler, which will copy protected disks in 18 seconds.
If you have a stack of unprotected disks, the Mass Dupe function is awesome.
However, as we all know a lot of original disks came with copy protection. Back in the day, several Hacker programs provided support for the MSD drives. You might have noticed these options as a kid and never knew what they meant. Now you do!
Software Support
All the folks who made and sold copy software loved the MSD devices for obvious reasons. As a result, their software was made to support it, too. Some examples include classics like:
“TOP SHELF”
Kracker Jax 128 Dual Cannon
Nick’s Swift Copy
FAST HACKEM
MSD’s own Utilities programs
“THE WELL”
Uni-Copy
Sure Copy
Mr. Nibble
Maverick (Upgrades & Goodies)
The Clone Machine
Back in the day, CLD - the folks that produced the Mass Dupe ROMs - also created a special disk.
The disk does supposedly exist but it is not needed for the Mass Dupe function. It’s nothing special, has a few programs, a program to check that the extra SRAM is installed and OK, the other is just a plain vanilla MSD SD2 copy program. The Kracker Jax copy programs written specifically for the MSD SD2 are the ones you probably want to find; they even made one that works specifically on the C128 and takes advantage of the extra memory of the C128.
And, you can actually load those nibbler copy programs up and then disconnect the SD-2 from the computer then copy disks for days - totally on its own!
Reminder: Even though their nibblers may copy a copy-protected program to run in a 1541, lots of copy-protected programs that try and load their own routines into the drive RAM won’t run on the MSD drives because of the different hardware, mainly the 6511Q processor.
So you can copy all you want, but you’ll want to use a different drive to actually run that software.
Pretty EF’ing sweet, though! So come over to my house this Saturday night and bring your disks and let’s get that Copy Party started!
