Written by 2021 by Joerg Walke, visit his webiste for the most actual version!
The Junior Computer ][ is an expanded version of the original Junior Computer. To make it more useful, I’ve equipped it with 32KB RAM, 8KB ROM and an onboard RS232 serial interface for connecting a terminal or a printer. For the use with a terminal, I also wrote an extended monitor program thats included in the bigger ROM. The development of the Junior Computer ][ is still in progress, so some other features will find its way to the mainboard.On the picture above, you can see the actual rev. 2 board of the Junior Computer ][.The new revision 3 board has arrived!…all components assembled and soldered…and it works fine!

Thanks to Friedrich Hofmann I have added information on the Video PLUS II and DRAM PLUS borads to The Computerist page.

Recently on Ebay a KIM-1 lookalike showed up. The PCB is inspired but clearly newly designed. It is called ‘Scandinavian’ because another identical ‘clone’ had a scandinavian businness sticker on it. Armin Hierstetter bought it and send me photos shown on the “KIM-1 related’ page.

The Data Handler is a SBC (actually two boards!) built in 1975 by Western Data Systems Corporation.One of the first computers based upon the then new 6502, as the KIM-1. Jolt, OSI 300.

Additions tot the TM and KIM-1 information:

The story Of TIM (documenting the work by Ray Holt and Manny Lemas

The Story of the KIM-1

(from Ch.1.5 of “On the Edge: the Spectacular Rise and Fall of Commodore”)

Update 24 march 2022: added KIM-1 Re v photos from HomeComputerMuseum (thanks Bart!)

The KIM-1 went trough several revisions without any change to the specifications. The first revisions appeared as MOS Technology products, the label MOS in in the front top right corner. When Commodore took over MOS late 1976 the label changed to Commodore C MOS.

MOS did three versions, the unnamed first one, a Revision A and a Rev B. I have never seen a Rev C.
Commodore MOS did Rev D to G, starting in 1977 and well into the 80ties. Many KIM-1s were sold, first to industry and later to education and hobbyists. Nowadays KIM-1s are not rare but have become quite expensive, collectors value especially the early ones with a white 6502 IC. The KIM-1 was an OEM product by Rockwell, with its Rockwell branded documentation and a Rockwell sticker at the right top part covering the Commodore MOS label. I know of at least two versions by Rockwell, a Rev D and my Rev F.

See this page for images of the revisions known to me.