Monster E&L Breadboad System (Patreon)

Thanks to your support, I just got a big bad vintage solderless breadboard system off eBay. Actually, two of them.

We use breadboards quite a bit in the lab, and when there are several of us and several projects running at the same time, I need to have enough around for everyone. 

I have a pile of simple bare breadboards of course, but the most popular item is the E&L Instruments Digi Designer DD-1, pictured below. 

It comes from late Ron Crane's home lab. Ron was former Xerox, co-founder of 3COM with Bob Metcalfe and designer of some of the very first Ethernet cards. We worked with him on the Alto restoration.

It's super convenient. It has an integrated 5V supply, a little clock generator, 4 slider swtiches to create high/low TTL levels, two push buttons that create clean, debounced pulses, and 4 LED indicators. It has been very useful to test the more complicated TTL chips like the Intel memory controller or the intelligent displays from the HP 9825.

But with the bigger chips, we tend to run out of inputs and outputs. Ron had already added a bracket at the back to mount an extra board (or maybe it was an option?). So I used it to put more LEDs, or occasionally 7-segment displays. Last week I added another extension to the extension, which holds two 7-segment hex decoders.

But while I was surfing eBay for something unrelated, the vendor I was looking up turned out to have an E&L system for sale that I had never seen before. 

Holy macaroni! This must be the mother of all breadboard systems! 3 adjustable power supplies (two up to 30V!), with an amp and voltmeter switchable to each, 14 input switches, 12 output LEDs, a pulse generator, a waveform generator, and best of all, an edge-card connector that would work with many of my HP boards. I couldn't pass this up!

It arrived in one piece, and much dirtier than shown in the eBay photo. It is huge and very heavy, much bigger than I expected. It cleaned up OK. Two out of the 3 fuse holders at the back are broken, which you could not tell from the auction, the edge connector is chipped (which you could tell), and two switches are broken. Par for the course for eBay. I have not tried it yet since I need to repair the fuse holders first.

And while I was at it, I picked up another smaller system, a BB-4. It has a triple power supply and 3 boards, but no buttons or LED. It might come in handy to build temporary analog mod/demod circuits for the Apollo Comms project. 

This one arrived in mint condition, with original manual. Apparently this was a kit that you could build yourself, although the wiring in this unit appears to have been done at the factory. It worked right off the bat, did not even need to readjust the +5V, which was right on the dot.

Here is a family photo of the three E&L systems:

With so many breadboards, I think I can start an electronic bakery...

Marc