1050 case differences

[StickJock]

There was a recent thread that mentioned that there were two different top shells for the 1050 floppy drive.  As it happens, I just came across a box with an 800 & two 1050s.  They were pretty dirty, so I disassembled everything to clean them.  The two 1050s had different top cases, so I thought that I would take some pics of the differences and post them here. 

 

 

Here you can see that the front edge has different interlocks that go to the front frame.  You can also see that the hold-down post (center left) that presses on the drive mechanism is in a different location and is a different height.  The one on the left presses on the aluminum drive casting, and the shorter one on the right presses on the shaped sheet metal closer to the front.  The rubber bumpers are different between them as well.  The ones on the right seem to be just rubber "bump-on feet".

 

 

This shows a closeup of the left top shell and the front bezel.  You can see that the interlocks are like loops, with simple projections on the top shell.

 

 

 

Here is the closeup of the right shell.  You can see that the bezel has groups of three "finger hooks" to hook onto beefier projections on the top shell.  Some of the top shell has been cut back where a (probably write protect) switch was added.  There was also a small plastic hook on the bottom right (top left in pic) of the bezel, which broke off.  I'll probably CA it back on.  The other bezel doesn't have this hook, and both bottom shells have the tab for the hook (bottom shells are same part #).  This one also has plastic ridges on either side of the drive opening that the one above doesn't have.

 

 

[+Nezgar]

Check the label, and I believe the difference is:

1. Made in Singapore, Tandon mechanism, three fingers faceplate. PCB not screwed to bottom case.
2. Made in Hong Kong, World Storage Technology mechanism. Maybe wide-bar interlock with top case? Post from top case contacts mech in different location compared to Tandon. PCB may be screwed to bottom case.

[StickJock]

Neither PCB was screwed down, and I'm pretty sure that they are both Tandon drives, but who knows what happened to these drives in the past 35 years.  Well, nothing in the past 25 since they were in a box in a closet, but prior to that...?

I did think that it was odd that the drive from the case with the longer, rearward post had discoloration on it from where the shorter, forward post would press.  It seems that at some point in it's life, the case was swapped on this.  It is also missing the four lower bumpers on the drive alignment pins, and has what appears to be a homemade US Doubler installed (stacked RAM with the wires across the top & eprom instead of masked ROM, and case label has "USD" written in sharpie).  The other drive has an actual ICD US Doubler in it. 

 

These drives, along with an 800, were in a box (no cables or power supplies) in the back of a closet for 25 years.  They belonged to my wife BitD.  I didn't even know about them until Saturday when I was pulling out the rest of my old 8-bit stuff from the closet.  Since I retired last year, I figured that I would get back into them.  All of my old stuff was stored in their original boxes (2 1050s (one with USD), 800, 130XE (with 320K), 850, trackball, 1020 plotter, Anchor 2400 baud modem - still haven't come across the Epson RX80 F/T+ yet).  Yeah, I'm a packrat. ?

 

 

[+Nezgar]

I just opened both types of drives for comparison.

• WST drive cover has the 'bar' interlock for the faceplate, Tandon has the 3 'fingers'
• Also note the difference in the post towards the middle of the drive, the WST one is about 1 inch long, the tandon one is about half an inch long. So, you wouldn't be able to close a WST cover onto a drive with a Tandon mech.

[+Nezgar]

And this is what a WST "World Storage Technologies" mechanism looks like. Quite visually different compared to a Tandon mech:

[StickJock]

Both of the drives are Tandons.  The longer post is farther back, so it pushes on the aluminum casting (or, least misses the taller part of the drive).  The shorter post pushes on the sheet metal.  Obviously, it did close as both drives were sealed up with the 4 corner screws & 2 bezel screws.  My wife said that she got them from her sister, whose husband probably bastardized it back in the 80s.  He probably put the wrong top & faceplate on it, maybe while upgrading several to USD?

 

I still need to clean the mechanisms & power them up to see if they still work.  Oddly, one was set as D4.

Edited February 12, 2020 by StickJock