|
|
How to Convert a CMD Hard Drive into an HD-Zip Drive
by Dale Sidebottom and Roger Lawhorn
(this article first
appeared in the May 1998 LUCKY Report Newsletter)
As our skills grow, so grow our needs. Thus, we find greater need for more and more memory in our Commodore drives. Roger and I recently converted 650 PostScript fonts from a Macintosh CD to the Commodore. How much memory did that take? 50 megabytes! I only have a 40MB CMD HardDrive, and it would not even store all of my fonts!
I looked around for a solution, and Maurice Randall had heard of a lady named (I pray that I have her name correct) Barbara Gann, who had converted her CMD HardDrive into a ZipDrive. So far as I know, she was the first to prove it could be done, and I admire that.
So with encouragement from Maurice and Roger, I decided to follow in her footsteps and try it. This is a report semi-technical description of how Roger and I put it together. The technical part is written by Roger, of course. He would like you to know that any errors in this article are my fault, since I had it last!
I already had a 40MB CMD-HD, and I did not want to lose what was in it, so I called CMD and asked what they would charge. Each SCSI hard drive, such as those we use with our Commodores, has four basic parts...the metal case, the power supply, the controller (the SCSI mechanism that contains the on-board instructions for the drive), and the hard drive mechanism itself. Well, I needed everything except the hard drive mechanism, and CMD told me that they would sell it to me for $239, which is $30.00 below the cost of a 40MB drive.
If you are not familiar with a Zip drive, it is a special device that allows us to store programs and data on 100MB disks. Actually, each of them is a hard drive in a disk. It works like a hard drive mechanism, but you can purchase them for less than $25.00 apiece. If installed, a Zip disk could up my storage from 40MB to looMB immediately, and when I filled that memory, for the price of a dinner and a movie, I could put in 100MB more.
I also realized that if I got the new one to work, I would have the confidence to overhaul my old CMD HD40. Soon I could have two 100MB drives with replaceable hard-drive disks. Now that should take care of almost any Commodore storage problem!
I purchased the case, controller, and power supply from CMD. I still needed a hard drive mechanism. So I bought an internal SCSI Zip Drive from Iomega Inc. Actually I bought it through Computer Shopper magazine for $129 plus shipping. Roger and I successfully installed it, and it is everything I hoped for.
If you want to create a "Zip/CMD Drive" you will need the following:
A CMD Hard Drive or a Case, Controller boards, and Power Supply from CMD.
An internal SCSI Zip Drive from lomega Inc.
Sheet metal to make a bracket for bracing the Zip drive (I cut up the braces that came with the Zip drive itself.)
Two to four small machine bolts with nuts and washers to fasten the sides of the bracket
Two size 4-40 machine screws, one quarter inch in length to screw into the bottom of the Zip drive. (1 could not find them that short, so I bought them longer and used washers.)
Set of Allen wrenches (very small)
Regular Philips screwdriver
Flathead screwdriver (very small)
Socket set (small sizes)
A hacksaw
Tinsnips (1 used two pair, one to cut straight and one to cut along a curve.)
Carpenter or other razor-sharp knife
Pliers to bend the sheet metal
An electric drill and small bits.
You will need to observe certain precautions:
1. All electronic devices are sensitive to electrical static discharge. You must ground yourself. If you are not familiar with this you should have a service professional do this for you as you WiLL be voiding your warranty by doing this procedure.
2. You must make extra certain that NO metal dust particles get onto any of the internal boards!
Let's Begin
Make sure you are working on a clean large work area so that no screws are lost.
If you are starting with a regular CMD HardDrive, you must disconnect the drive from the back of the case. (Roger's note: I nearly ruined a drive once, because I did not know about this screw.)
Grab your allen wrenches. Turn the CMD HD around so that you are facing the back-side. Run your finger over the upper-left-hand comer. You should feel a small circular hole under the external covering. The back of the drive looks like solid metal, but actually it is covered by a thin sheet of plastic-like material. Using the knife, try to peel back the outer layer starting at the upper left corner until you see the allen screw. If you cannot peel it back, simply cut a round hole with the razor-edged knife around the head of the hex screw. Now remove it.
Next, remove the four screws from the bottom of the drive. There is only one way to remove the top. Pull the top off the case moving towards the front of the drive. Moving the other way can bend the bottom portion of the case.
If you need to remove the hard drive mechanism, simply lay the drive on it's side and remove the screws from the hard drive located at the top. Holding the drive in place, turn it over and remove the other two screws. DO NOT let the HD drop onto the motherboard below it. Remove the SCSI cable and power cord from the back of the hard drive mechanism and then you can set it aside. You won't need it anymore!
Next, I suggest that you test to see if you have a working system. On the top of the Zip drive, you will see a diagram describing how to set the jumpers on the back of the drive. You must set the drive to device zero (0) in order for it to work with the CMD-HD motherboard. You must also make sure that the jumper is set so that the drive is terminated. You will see four sets of tiny wires which may or may not have a jumper. If you want to set yours properly, the set of wire-ends to the left will need a jumper to connect them, the other three sets will not.
If you do not have a CMD HardDrive of your own, and just ordered the case, controllers, and power supply; I suggest you think strongly about buying the book and accompanying disk which spell out in detail how to format and utilize a CMD HardDrive. Even though the Zip drive will replace the usual CMD hard drive mechanism, the controllers belong to CMD! So they write the rules.
Now, hook it up to your C64/128 and load the CMD program known as "LLFORMAT". This stands for Low Level Format. Run it. If it can't find your Zip drive as device '0' or at all, then you probably need to reset the jumpers. Formatting can take up to 10 minutes. The Zip drive light should flicker the whole time.
Now run "create sys.64" or "create sys.l28" in order to create the partition table and write the system info. Next run "HD-TOOLS" and partition it like a normal hard-drive. The easiest thing to do is to divide it into six 16MB partitions. Make sure everything works before you proceed.
If everything is in good order, you are ready to tear down your drive to the bare metal. There are four screws holding in the motherboard. Remove them. Unplug the front panel, the external SCSI port, and the ON/OFF switch from the motherboard. Place the motherboard onto some anti-static foam, plastic, or some clean newspaper will do.
Grab a pencil and draw a line across the top side of the control panel motherboard. This will mark where the Zip drive will lay on the top of the board and where to cut into the front case. Remove the control panel from the front inside of the case using a socket wrench. Be careful to remember how everything goes back on. WRITE IT DOWN! You WILL forget!
Now that you have removed all drive parts from the steel case, you may now start the fun part. Hold the bottom of the Zip drive against the line you drew. The top of the Zip drive should be level with the top of the font panel. The horizontal line must be just over one inch from the top. Next, center it and mark the outer edges of the Zip drive. You have now outlined the hole that you have to cut out of your front panel.
How you cut out the hole is your own business. If you would like to try it our way, cut the verticals with the hacksaw and the horizontals with the snips. Of course, with the snips, you have to cut down a little bit at a time. Only bite off what you can chew.
Some marring of the front face is unavoidable. We used black electrical tape to cover up any scratches and to give the final product a finished look.
Now that you have a perfectly square cut (we hope) the exact size of the front of the zip drive (hmmm...), you will need to make sure that you wipe down the case with a DRY towel. Now make a bracket out of sheet metal. As I said, I 'cannibalized' the metal brackets that came with the Zip drive. Either cut them, or other sheet metal, so that you can make a bracket 5 inches long with at least a half inch folded down on each end.
Measure the distance between the centers of the two small screw holes in the bottom of the Zip drive mechanism (approximately 3 3/4" apart) and bore two holes just large enough to accommodate the 4-40 sized machine screws. Next, lay the head of the Zip drive into the hole you cut in the front panel, and mark where you must drill your holes in order to fasten the sides of the backet to the steel sides of the CMD hard drive casing. (Check the picture of the insides of my drive to see how I connected the bracket.)
First, make sure everything fits by fastening the bracket to the bottom of the Zip drive with the size 4-40 screws. Then pin the brackets to the sides by using the small bolts (without tightening them). You should now have your Zip drive fastened in place sufficiently to determine if your hard drive casing will slip over the top. Remember, slide it from front to back, just the opposite of the way you pulled it off. If it does not fit, then this is the time to make adjustments.
When everything fits, then it is time to set the Zip drive aside and clean up. Be careful to NOT leave any traces of metallic particles anywhere. They might short the drive out! Remember, CMD cannot give you a warranty on your work. At this point, you have already proven that their equipment (and the Zip drive mechanism) is good. If you break something or short it out now, there will be no free replacement policy. Clean everything thoroughly!
Now for the fun part...putting it all back together! Did you remember to write everything down? Like how the ON/OFF switch goes back on?
First of all, fasten the sides of the bracket to the sides of the casing. This was by far the most difficult part of the reassembly for me. When these are fastened, the drive should be held securely and you are ready to proceed.
Place the control panel back on next. Make sure that you do not tighten down the nuts too hard. Doing so will cause the control panel to stay on constantly and the drive won't work!
Let's go through the check list:
Did you put the motherboard back in?
Did you put the control panel back on? Did you connect it back onto the motherboard?
Did you hookup the ON/OFF switch and external cables?
If so, that's everything.
The cables are easier. Just match the colors on the power cable. The data transfer cable has notches so that it can plug in only one way.
Put the top back on and power it up. Watch for unusual happenings like no lights at all or all lights on constantly. You may have inverted a cable or hooked up the ON/OFF switch wrong in this case or have the control panel fastened too tightly. If the drive goes through the normal power-up sequence on the front display, then you have probably done everything correctly. You now have a $360 CMD/Zip drive that is lOOMB in size with this added advantage. When it fills up, you can install the next lOOMB "hard drive mechanism" in only a few seconds!
NOTE - On July 21, 2001 Click Here Software took over production of all CMD Hardware. If you want to tackle this project check the Click Here Software web site for availability of the HD components.
This is the internals of Dale's HD-Zip drive.
bravenet.com