Serial197

Crosley / Serial #197

This Kenbak-1 computer is probably the best documented of any, and lead an era of renewed interest in the Kenbak-1 around 2005. It was acquired by Erik Klein, a vintage computer enthusiast, who made a number of high resolution photographs and published it to his website. Along with some schematics which came out about this time, people could finally understand the computer, and even make one up themselves. The provenance of this computer is told <HERE>.

Most of the below were shared by Erik on his website., but the first two are unique, emailed by him after request.

Photos of back and Serial Number

I asked Erik Klein if he knew his Serial Number, or had any photos of the back of his computer. We were both surprised to realize he's never really noticed the serial number, and of all the photos he's taken, he never took one of the back. So below are the photos he took and sent.

3000 x 4000

High Resolution PC Board Photos:

These below high resolution photos from Erik's site started excitement about the Kenbak-1. Visit his vintage computer collection website https://www.vintage-computer.com/

Component Side Overview

2592 x 1944

Back Side Overview

2316 x 1440

Upper Left

2592 x 1944

Upper Middle

2592 x 1944

Upper Right

2592 x 1944

Lower Left

Lower Middle

2592 x 1944 Shows the serial number 197 is stamped on the circuit board. We didn't originally know that the serial numbers were stamped on the PC board also. Had anyone noticed this was the serial number, I wouldn't have had to hound him for a back photo.

Lower Right

2592 x 1944

The (Solved) Mystery of IC99

This machine became the template from Grant Stockly's Kenbak-1 Series 2 kit (http://www.kenbakkit.com/) which was sold to vintage computer enthusiasts in the early 2000's. Grant borrowed a blank board from John Blankenbaker, to reproduce, but then used the photos on Erik's website to figure out IC's and components, having to email owners to figure out values of capacitors and resistors. Nobody seemed to notice that IC99 location in all other Kenbak-1's is an empty spot, no chip, but in this particular computer, it had an IC inserted. Yet the PC board didn't show any connections to this. After several people had built the kit, they noticed the IC99 was getting hot (probably as the inputs were left floating, which you can't do with these early TTL chips) it was brought to everyone's attention that nothing should really be in that socket, it should be empty. The below photos showed how some external wires were attached in this IC, but the reason for this modification, the extra IC and the wires, eluded explanation until Tom Crosley was identified as the original owner, and he explained how he had interfaced it to a teletype.

Forum Discussion

Click on the left image to see the Stockly Forum discussion about this IC99 when discovered. There is some incorrect incorrect conjecture, now known to be false, but interesting none the less.

Annotated for IC 99

1053 x 576 (just a crop of above photos, back side of board.)

Annotated for IC99

2200 x 1417 (just a crop of above photos, component side of board.)

Generic Photos of Exterior

The below photos are nothing unique, they are simply medium resolution directly from his vintage computer collection website https://www.vintage-computer.com/

800 x 315

800 x 263

800 x 427

More Tom Crosley Information:

Tom has been active on Quora for years, with lots of postings, and he wrote several letters to the Amateur Computer Society Newsletter where he was trying to connect with other Kenbak-1 owners, and talking about his plans to modify the hardware.

Here's a PDF of one quora posting

Here's a PDF of another quora posting

Tom Crosley Bio

1080 x 1920 Tom posted this to quora telling a bit about his experience with the machine, and interface.

Google Sites

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