So following along from getting my REX installed and playing with it, the next addition for my little M100 kit was a Tandy Portable Disk Drive 2:

Tandy Portable Disk Drive 2 1

Tandy Portable Disk Drive 2 2

As the name suggests, its a portable 3.5” disk drive that goes with the Model 100, can run on AA batteries or 6V DC and reminds me very much of a top loading VCR we owned a long time ago.

The drive itself appeared in fantastic cosmetic condition when it arrived - however it did not come with the serial cable to connect it to the M100 nor any disks. I didn’t think the missing cable would be a huge deal - but as it turns out I should have asked the question before purchasing the drive. The cable is not just a straight serial cable, and has to adjust some of the voltage levels between the M100 and the drive to get things to work. I started looking online at the documentation people have produced around making your own cable. It was at this point someone very kindly offered me a spare cable that they had excess to their needs and posted it to me. To that individual - thank you!

Once I had that cable I was ready to give the drive a good clean and service. I had also ordered a replacement drive belt and some double sided, double density disks in the meantime too - which had also arrived. The drive will only read one side of the disk, and only format it to 200K, but they work. The drive only requires a few screws be removed for the plastic case to come off:

Tandy Portable Disk Drive 2 3

Tandy Portable Disk Drive 2 4

With the top, bottom and front plastic casing removed, the drive came out as a single unit. It was at this point that I gave all of the plastics a good clean. Removing a few more screws allowed the shielding to come off and the main PCB was revealed:

Tandy Portable Disk Drive 2 5

Removing one more screw allowed the PCB to be separated from the drive:

Tandy Portable Disk Drive 2 6

As you can see in the photos the drive was very clean inside, which was a nice change. At this point I replaced the drive belt:

Tandy Portable Disk Drive 2 7

You can see how stretched the old one was compared to the new one. I also lubed up all of the mechanical parts in the drive. I then turned my attention to the small power supply PCB:

Tandy Portable Disk Drive 2 8

The six capacitors all actually looked pretty good - but I replaced them anyways:

Tandy Portable Disk Drive 2 9

Tandy Portable Disk Drive 2 10

As a last step I gave the drive head a good clean with some isopropyl alcohol and reassembled the drive. I then grabbed the serial cable and plugged the drive into my M100:

Tandy Portable Disk Drive 2 11

I then turned on my M100, went into TS-DOS, hit F4 to bring up the disk menu and after a brief read of the disk, it showed the disk in the drive as unformatted:

Tandy Portable Disk Drive 2 12

So I formatted the disk - which worked first go:

Tandy Portable Disk Drive 2 13

I then saved a file to the disk, and read it back from the disk. All worked as expected:

Tandy Portable Disk Drive 2 14

I now own a vintage portable storage solution for my M100!