What's the rarest or most unusual computer-related item do you own?

[Rick Bensene]

On 12.01.2017 20:49, Rick Bensene wrote:
>>
>> - A Tektronix 4052 desktop computer (bit-slice implementation of Motorola 6800 CPU) with very rare RAM Disk module installed under keyboard

To which Jos D. asked:

>Is this RAM disk module documented ?
>Sounds like a possible solution for my 4052, such that I would not have to resurrect those  DC300 cartridges from the dead.

Not to my knowledge.  I haven't found any documentation of it.  I am not even sure it was ever a real product offered by Tektronix.
It's a bit fussy, too.   It has its own power supply that bypasses the power switch so that it's always on.  That's how it keeps the RAM alive.
If the mains are removed, the RAM Disk content is gone.  Sometimes when I switch the machine off, the content does get scrambled, and the next time the machine is powered up, it gets a device error when it tries to talk to the RAM Disk, ad doesn't recognize it anymore.   Unplugging the mains and leaving it for a while seems to clean things up so that the RAM Disk will work again.   It has its own firmware on the board that augments the commands within BASIC to provide for saving and retrieving programs from the RAM Disk, and getting a directory of its contents, as well as deleting files.  It does not seem to work with binary files or anything else other than BASIC programs.   

I know what you mean about the DC300 carts...what a lousy design...at least from a longevity standpoint.  I've had numerous nightmares with those cartridges in a number of vintage systems that I've got.    Broken tension bands, sticky tape...just plain bad stuff.   Plus, the tape transports in the 4051/4052 are fussy as can be.   I have a 4907 single 8" floppy disk drive for my 4051, and it works great, but I don't have the proper ROMpack module to use it with the 4052, which apparently needs a different ROMpack than the 4051 to talk to the 4907.  So far, such a ROMpack has proven elusive.

-Rick