Tecmar Mac Drive (10 MB) A serial hard drive?! (The first Macintosh external hard drive)

[Mac84]

I’m assuming the drive was used at some point in time - and hoping there’s data on it. I’m mainly curious to see what goodies are on it versus using the blasted thing as a new drive, but I guess that can be plan B.

Since one of the boards seems to be connected via SASI/SCSI, I’m going to experiment using BlueSCSI Initiator mode to see if it can read anything from it. You never know!

 

[JDW]

Since one of the boards seems to be connected via SASI/SCSI…

Really? SCSI?

I’m assuming the drive was used at some point in time - and hoping there’s data on it. I’m mainly curious to see what goodies are on it…

If you don’t have an ancient PC that might me able to extract data from it, I’d suggest reaching out to Adrian of Adrian’s Digital Basement because I know he has such a setup and he might be able to extract data from it if you ship it to him. Packing it to avoid damage will be critical, but since you said that heads never moved, then I must assume they are PARKED and not hovering over the platters, which would be required before shipping it. My HyperDrive doesn’t auto park the heads, so GCC wrote a head Parker Utility.

 

[Mac84]

The thought is, that this board converts the drive to SASI/SCSI (at some point), the pinout of the 50-pin cable seems to confirm that. So that's one avenue to explore. At least nothing exploded...

The good news is the drive head is moving! If I manually move the head a bit out of the parked area, 5-6 seconds after it powers on, it will retract. I'll need to probe the test points to see what state the drive is going in afterwards.

I did try another Mac 512K, to determine if the serial ports on my other Mac were the culprit, but I got the same error as before.

If you don’t have an ancient PC that might me able to extract data from it, I’d suggest reaching out to Adrian of Adrian’s Digital Basement because I know he has such a setup and he might be able to extract data from it if you ship it to him.

Way ahead of you, I've been picking Adrian's brain about this since I picked up this hunk of metal at VCF Midwest.

Will keep everyone updated as I press on...

 

[snuci]

I had bought one of these some time ago quite a while back but never actually tried it because it has issues with the power supply and drive. I suppose it's waited long enough for me to look at it. The good thing is, I have software and the original cable (and box too!). What I don't have is documentation so I can't help there. Anyway, here's my drive. I've imaged the diskettes here: https://vintagecomputer.ca/files/Apple/Macintosh/Tecmar/ I have also had a decent amount of experience with MFM and SASI so I'll check out the internals and see I can figure out. I can also image my drive if it actually works before doing anything.

Hope the floppies help. I will also check the serial cable pin out to see if it's straight thru. FYI, I was also told this worked on or with a Lisa. I am not so sure of that but if I can figure out the files or access it after repairs/restoration, we'll see what's on it.

Good luck with yours.
Santo

 

[snuci]

Also, not straight thru. I have to assume this is the correct cable as it's the only one that came with it. Of course, I don't know for sure but it's a good bet. Hope you can figure it out from this:

 

[Mac84]

I had bought one of these some time ago quite a while back but never actually tried it because it has issues with the power supply and drive. I suppose it's waited long enough for me to look at it. The good thing is, I have software and the original cable (and box too!). What I don't have is documentation so I can't help there. Anyway, here's my drive. I've imaged the diskettes here: https://vintagecomputer.ca/files/Apple/Macintosh/Tecmar/ I have also had a decent amount of experience with MFM and SASI so I'll check out the internals and see I can figure out. I can also image my drive if it actually works before doing anything.

Hope the floppies help. I will also check the serial cable pin out to see if it's straight thru. FYI, I was also told this worked on or with a Lisa. I am not so sure of that but if I can figure out the files or access it after repairs/restoration, we'll see what's on it.

Good luck with yours.
Santo

THANK YOU @snuci for your reply and sharing your knowledge!

If you need any help with the power supply, I'm happy to take photos of mine. Mine has two RIFA caps inside, and I was able to replace them with the same type and value I used in a Mac 128/512/Plus analog board.

I was super curious about the cable, this explains a lot - the cable I've been trying is straight through. I'll try to create a cable like yours. I believe yours is the original, as it matches the color and unique connector shroud I've seen on eBay. Funnily enough that connector apparently doesn't fit well on some Macs, so you have to remove the metal housing.

 

[snuci]

It's never easy. The RIFA caps look as fresh as they day they were delivered from hell. I do have a couple of large caps where one has the outer jacket split along one side and another that looks like it was starting to. I'll have to remove the caps and check them. Hopefully it's one of those that "blew up".

First off, nobody told me there was a 68K computer in one of these (albeit 8-bit bus). Very cool. It's definitely SASI. There is a Xebec 1410 MFM to SASI bridge board in there. Same one I used with the Mindset hard drive. They are pretty reliable. Second, they were built like a tank but there is zero shock prevention. I guess GCC Hyperdrives were a little overly cautious at the time.

A picture of the Tecmar "Macdisk PCB" with a Motorola 68008 in it. You could expand the memory. I guess that's a cache of some sort? Very interesting. I'll also back up my firmware. I am curious if you have the same version.

EDIT: Just took a closer look at your pictures. You have the same version as well.

Anyway, I'll take a look at my power supply tomorrow and see if I can spin up the drive and archive it. I just worked on a Tandon PC with a Tandon drive last week that I had to give up on because the head stepper motor was weak and it worked one i every 20 tries or so. There was nothing worth saving on it so it was okay. Hopefully, this is better.

Santo

 

[Mac84]

Awesome! My ROM appears to be newer (1.7 instead of 1.2). I think the RAM is used for the print spooling feature too.

I've attache both of my ROMs, one was on the "power" board (with the M68008) and the other on the "data" board with the Z80. They're attached to this post.

Also, I'll be streaming on YouTube as I make a cable later today, hopefully this ties it all together.

 

[snuci]

I'll try to check out the stream later today. Perhaps I am mistaken but I was referring to the chip on the Macdisk board marked 7000007, v1.2 which is the same as mine. I also see you have a Tandon TM600 series drive. I have not had the best of luck with those. Various models were used in the early TRS-80 5MB external hard disk units and a different model in the Commodore D9060 and D9090 external hard drives. Two of my four were bad. Hopefully you make out okay. If it doesn't sound like a plane taking off, you have a much better chance of it working just fine, Good luck!

 

[JDW]

...they were built like a tank but there is zero shock prevention. I guess GCC Hyperdrives were a little overly cautious at the time.

The rubber gel-filled shock absorbers used in my HyperDrive kit have done well through the years, as you can see in these photos:



The drive is completely suspended by them.



That was an appropriate measure to take to protect those extremely sensitive and expensive drives at the time. But despite those shock absorbing precautions, even at the time I obtain this kit many years ago, the shock indicator had turned red (either through time or because of shock):



So there are no rubber pieces used to mount that HDD inside the Tecmar enclosure at all? Really?

 

[David Cook]

Also, not straight thru. I have to assume this is the correct cable as it's the only one that came with it. Of course, I don't know for sure but it's a good bet. Hope you can figure it out from this:

1 to 1: GND to GND
2 unused: +5V
3 to 3: GND to GND
4 to 8: transmit+ to receive+
5 to 9: transmit- to receive-
6 unused: +12V
7 to 7: external clock to external clock
8 to 4: receive+ to transmit+
9 to 5: receive- to transmit-

A RS-422 crossover cable with external clock pin

 

[Mac84]

It freakin' WORKS! Woo-hoo!

Huge thanks to @snuci for sharing the cable pinout. I created my own crude cable, and inserted the MacDrive 2.3 boot floppy... and my Macintosh 512K booted from the floppy, and then accessed the hard drive! I was able to successfully backup the entire drive. Only about 2.5 MB was used out of the 10 MB drive.

My sincere thanks to everyone who helped me with this and who listened to me yammer on about this thing for the past few days.

Here's a video clip (28 seconds) someone trimmed of my live stream where it booted up with the drive for the first time. And the full 6 hour live stream is below for reference.

The Welcome to Macintosh screen with the Tecmar software installed on the boot floppy.

The Mac booting from the MacDrive!

The Volume manager software, showing the volumes on the drive.

The drive accessing data, showing a solid red LED:

Some things to note about the set up:

1. It doesn't seemingly work with my upgraded Macintosh 512K with Mac Plus ROMs. The system will display the error of it can't find/recognize the drive. I read about some Mac Plus incompatibility from old bulletin board posts, so that explains that.
2. It does work with a Macintosh 128K and Macintosh 512K, I'll have to test it with my Mac 512Ke.
3. The Tecmar drive acts in a similar way to the Apple HD20 external drive. You'll need the Tecmar boot floppy (System 3.2 w/ the "Volumes" suitcase file and "Volume Manager" application). Once it boots, the floppy disk is ejected and the Mac boots from the Tecmar hard drive.
4. The hard drive cannot be accessed without the boot floppy (seemingly). You can't boot from an HD20/SCSI HD and then mount the Tecmar drive.
5. I only needed to let the drive turn on and spin up for 5-10 seconds before turning on the Mac.
6. I had the Tecmar drive plugged into the Modem port on my Macs using the special pinout cable. I'm unsure if it'll work via the Printer port. I did not try the pass-through serial port, which apparently has a print spooler for use with an ImageWriter.
7. The Tecmard drive doesn't want to mount if you boot from an HD20 drive (with an HD20 boot disk on the Mac 512k, even with the Tecmar software on it). As the Mac boots to the HD20 drive after the boot floppy on the Mac 512K. Even if the Tecmar software is loaded on the HD20, it won't see the disk. Well, unless you trick it... !! (see below... ).
8. Due to limitations of the early Macintosh OS and file system the MacDrive uses special "volumes" to split up data. These volumes can be user defined in size to help get the most storage space out of your drive. The software recommends volumes that are at least 200KB and no larger than 2MB. You can also define startup volumes.
9. You can only mount a few volumes at once. A Mac 128K can not mount as many simultaneous volumes as a Mac 512K. You can easily mount and unmount these volumes via the Volumes Manager application that comes on the boot disk.

How I backed it up with a BMOW Floppy Emu pretending to be an HD20 drive:

Backing up the drive was HUGE challenge because my hopes of using my Mac Plus and the BlueSCSI were dashed when I realized it doesn't like the Mac Plus ROMs. I was going to back everything up to floppies, but I didn't want to risk running out of disks etc.

Armed with a Mac 512k, a BMOW Floppy Emu and a real 400K external disk drive (and one blank floppy) I was able to make it happen. One thing I learned, is that you can actually trick the Tecmar drive to show, even alongside an HD20 drive! Here's how...

1. I used the Mac System 3.2 HD20 boot floppy and booted the Mac with it without any of the Tecmar or HD20 drives connected (in my case I don't have an HD20 drive, so I used the BMOW in Mac Hard Disk mode). Then, I used the Tecmar MacDrive 2.3 disk to install the Tecmar software onto that HD20 boot floppy, although I had to throw away all extras, like the HD20 Tester app and an ImageWriter extension.
   
   
2. Once the boot disk was ready (on the real floppy disk), I ejected the floppy. I then set the BMOW Floppy Emu into Mac Hard Disk mode, which requires 1 restart of the Mac to set the mode, and then ANOTHER restart once you set the HD20 disk. This means you have to time things correctly.
   
   
3. Once the Mac was restarted twice (to set the mode and once the HD20 disk on the Floppy Emu was selected), I then inserted the System 3.2 HD20 boot floppy I modified with the Tecmar MacDrive 2.3 software. It's okay to leave the Tecmar drive plugged in during the above process, as the drive isn't accessed until the special boot floppy accesses the HD.
   
   
4. The 'Welcome to Macintosh' screen appears, and then it says "Hard Disk 20 Startup", this is when you need to be sneaky. I kept pushing the power/reset button the Floppy Emu, so the HD20 emulated disk drive wouldn't "mount" before it loaded the MacDrive / Tecmar files.
   
   
5. This took about 10-20 seconds, eventually I saw the access light (and heard the drive seek) on the Tecmar drive. The "MacDriveTM System 2.3 installed" text is added to the Welcome to Macintosh banner, and the boot floppy is soon ejected, as the Mac boots from the Tecmar drive.
   
   
   
   
   
6. During this I let the BMOW Floppy Emu load the HD20 disk drive, once the desktop slowly loaded, a few seconds later I saw activity on the Floppy Emu. After waiting a bit, I saw the HD20 drive mount! This made it wayyy easier to backup everything from the Tecmar drive to the virtual HD20 drive.
   
   It took HOURS of fiddling to figure this out, so I hope this informaiton is helpful to anyone who travels down this path in the future.
   
   That's it for now, what a night!
   
   
   

 

[JDW]

Congrats, @Mac84 !

I didn't watch your entire video, but I did catch your exuberation and "Holy Crap if F'n works!"

Glad to see it was just the cable because those solutions really are the best kind. No soldering, cleaning or hacking required in that case!

Just curious though if there's a manual HEAD PARK utility in that software, similar to what the GCC HyperDrive offers. Or does that drive auto-Park the heads? If it doesn't auto-Park, it's best to manually Park them before moving the drive around.

 

[snuci]

Congratulations! I am an early riser so I was watching the live stream until just before midnight and saw most of the fun. I'll watch the rest of it today and coupled with what you wrote above (thank you!), I'll figure it out if I can get mine to work. I've never used my Floppy Emu as an HD20 so I'll have to sort that out to. I'll also figure out how to make the Mac Drive/HD20 boot floppy and see if there is anything interesting on mine.

Glad I could help in some small way. Your reaction to it working was classic
Santo

 

[snuci]

But despite those shock absorbing precautions, even at the time I obtain this kit many years ago, the shock indicator had turned red (either through time or because of shock):

I think it's age. I have two or three Hyper Drives and all of them have red shock indicators.

So there are no rubber pieces used to mount that HDD inside the Tecmar enclosure at all? Really?

Nope, no rubber whatsoever. The metal Mac Drive case is more heavy duty than I've seen with most hard drive enclosures of the period. It was well designed.

 

[Mac84]

Congrats, @Mac84 !

I didn't watch your entire video, but I did catch your exuberation and "Holy Crap if F'n works!"

Glad to see it was just the cable because those solutions really are the best kind. No soldering, cleaning or hacking required in that case!

Just curious though if there's a manual HEAD PARK utility in that software, similar to what the GCC HyperDrive offers. Or does that drive auto-Park the heads? If it doesn't auto-Park, it's best to manually Park them before moving the drive around.

I was shocked it was just the cable, I had a gut feeling the drive was okay, but this finally proved it!

The software has no ability to park the heads it seems (at least from what I see in the menus). The drive appears to retract the heads away from the drive as part of the power down motions. Also, there are shock absorbing rubber stoppers, two of them are hidden between all the metal brackets and PCBs.

Congratulations! I am an early riser so I was watching the live stream until just before midnight and saw most of the fun. I'll watch the rest of it today and coupled with what you wrote above (thank you!), I'll figure it out if I can get mine to work. I've never used my Floppy Emu as an HD20 so I'll have to sort that out to. I'll also figure out how to make the Mac Drive/HD20 boot floppy and see if there is anything interesting on mine.

Glad I could help in some small way. Your reaction to it working was classic
Santo

Thank you! Again, this wouldn't be possible with you testing the pinout for your cable. Thank you so much for that! I've added chapter markers on YouTube so nobody needs to suffer through the whole video.

Oh and yes, the ROM on mine is also a v1.2 - the "1.7" was a typo on my part! The drive I have is a Tandon TM 502 (serial # 4 30 00002476)

I'd try first booting with the Tecmar floppy, if you see the Tecmar HD mount and it has a bootable OS, then you can proceed like I did with the HD20 emulated drive.

The biggest pain is the Floppy Emu's HD needs to be reset multiple times to switch it into HD20 mode, and select a disk, etc.

I've attached my boot disk (with the HD20 + Tecmar files), technically any HD20 image should work, but I'll try and upload mine too. You just need to follow my instructions above and delay the HD20 from trying to be read from during the startup process... otherwise the boot disk will load the Mac OS from the HD20 and not boot from the Tecmar drive (this assumes your Tecmar drive has a bootable partition!)

Update: I'll upload the .dc42/.moof disks you provided to Macintosh Garden if that's okay, that way we can put all the proper software in one spot.

 

[snuci]

Thank you. This will help tremendously. Much appreciated and I appreciate the time markers too

Looking at my Mac Drive power supply, I saw some caps are out of spec so I made note of them for replacement. I saw two caps that were the same value but one was taller than the other. As it turns out, the taller one had exploded and increased in height. The internals were black like the outer jacket color so I couldn't spot anything weird at a glance. Caps are on order so I won't be doing anything until next week but this will definitely help.

I can check if my hard drive powers up and sounds okay. I am doubtful that Guesswein's MFM Emulator can read it properly (it tries to read the drives by what it knows about other drive types) so we'll see what happens.

Thanks again,
Santo