Way too much detail about breadboards

• breadboards & accessories
• several breadboard sizes & styles
• The classic EXP-300 breadboard that interlocks on all 4 sides
• The UBS-100 breadboard with 2 busses per side

Somehow I have the history of the breadboard company as it changed names from Elenco Precision to Continental Specialties to Global Specialties (with or without logo), and even labelled "Archer" for Tandy/Radio Shack. The .3" center breadboard's remained mostly unchanged for all these years. The Elenco Precision Breadblox model 9550 had slots in the center and only 2 mounting holes compared to the solid center and 4 mounting holes of the Experimentor 300.

Meet the family of Experimentor breadboards: quad bus, .3 and .6 inch centers.

I like the way the Global Specialties Experimentor breadboards interlock on all sides.

	Okay, who's playing with the TARDIS controls? I just accidentally stepped into a time-wormhole while sorting thru a magic box-o-parts and found 2 positively ancient Elenco Precision Breadboard Aids breadblox model no. 9550 (label) 9555 (tag) 550 tie points with two power lines And on the right, an AP Products 432-875 really minimal breadboard (no numbers/lettering, no busses, no mounting holes, no edge strips or tabs to click together).
	Elenco label & tag Oh my! None of the numbers match! On top is the rear label from the pre-model 300 breadboard. It's exactly same size (a little under 6"), 47 columns of clips, 5 per side, and one bus bar to each side with 8 groups of 5 contacts. But it's labelled the "model no. 9550, 550 tie points with two power lines". Technically, it's correct: 47 x 10 = 470 central contacts (called jacks on the tag), 8 x 5 = 40 contacts per bus, x 2 busses = 80 bus contacts, 470 + 80 = 550. But the bag label says "part no 9555" which does not match the breadboard's label or even the back of the bag which lists even larger "bredblox" (different spelling). The bag tag lists this as "no. 9415 with 470 jacks and 5 5/16" lgth" but I measured it as 5 15/16"! Had they made the no. 9416 with 590 jacks, that's 59 columns (vs. 47 of the model 300) which would have compared favorable to the 63 columns on the 6.5" ones by EIC (even the same length!)
	The top one with the binding posts is the Elenco, the bottom one a matching contemporary Global Specialties Corp Experimenter 300 breadboard.
	The Elenco is so old that the rear labels have neatly fallen off, revealing the same contacts still used by the Experimenter (as seen as label indentations). This opens up some interesting opportunities connect the binding posts to the bus strips mount the breadboard to a prototype system (PIC, AVR, etc) and wire the bottom of the tie-points directly to signals of interest so everything's just one jumper-wire away What insulation should I use under the bare contacts? fish paper? thin plastic? Whatever felt or fabric I have in reach? Robin Whittle did that years ago with his DIY Audio Patchbay made from a Solderless Breadboard. Inspired by this web page, he documented his other breadboards.
	Here's a vintage Continental Specialties "Proto-Board no. 100" I think that's a phenolic backing instead of aluminum for a ground plane. Perhaps the address helps date it? 44 Kendall Street / PO Box 1942 New Haven Conn 06509 A-ha! The PO Box address is on the 2nd one in this photo with the CSC logo and was retained as they moved to 70 Fulton Terrace.

• 30 on the tiny EIC
• 63 on the 6.5" EIC (the markings are clearer than the nearly identical Global UBS-100 breadboard)
• 47 on the Global Experimentor 300, 600

• The edge tabs on the small EIC do NOT match the larger EIC: they cannot interlock!
• The bus strips are separate parts held by the bottom glue-pad
  whereas the Global EXP breadboards are one solid piece
  

• The ubiquitious bug box
  Inside the BugBox are spare contacts from a REALLY OLD AP breadboard where I had to assemble it myself: push in all the contacts!
• the Archer/Radio Shack pack of scratchpads for the Global experimenter 300
• a tiny E.I.C. breadboard (the ones with color imprints).
  

And no-name generics
	On the right: This mail-order breadboard came pre-mounted on a blue metal backplane. There's no mfgr's name: the box says only "R.S.R. NE #304 solderless breadboard". What a gyp! only says "durable & 100% contact", no assurance of nickel-silver spring clip contacts NO markings at all for grid, busses (I suspect the busses are SPLIT in the center: notice the subtle difference in spacing!) NO edge clips or interlocks, only mounting holes to use more than one
	Here's the tiny EIC on top of the R.S.R. See how much easier it is to read the EIC markings and bus designations?
	This ebay Chinese clone has a clue! The split bus-bars ARE FINALLY CLEARLY MARKED well marked main points: even numbers on one side, odd on the other almost as good as a genuine EIC
	My NJIT 68000 trainer lab kit has a remarkably similar generic breadboard but with numbers. I inked the red marks to remind myself of the split busses.