Way too much detail about breadboards

Unobtanium! (discontinued product)
Just to prove it exists, here's my Global Specialties Corp "Experimenter 600" breadboard with a WIDE gap in the center for .6" chips.
See how neatly the 4: HP 5082-7340 hex displays fit!
Global Specialties is still in business

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.

A cardboard slide-rule of conversions from Continental Specialties Corp
at 44 Kendall Street, New Haven CT 06512
Why not something EE related
such as the resistor color code or parallel resistance calculator?

Other breadboard makers

The AP Products 201k ACE: All Circuit Evaluator was my first breadboard!
I bought it as a kit! I had to push in all the connectors from the bottom!
Here I'm breadboarding a Dale Wheat Pic-A-LCD (the manual is online here)
with a Sipex version of the Maxim RS232 transceiver.
My name's on the bottom using a genuine Dymo script lettering wheel.

Here's something few folks see: the clips from inside the breadboard.
These are spares from my AP ACE 201k kit.
I bought mine from an ad in Popular Electronics,
such as this vintage ad from July 1976 via Windell Oskay's flickr
AP and 3M no longer seem to make brotoboards but they still make test clips.

AP Products clips from 8 to 64 pins!
My largest is 64 pins at 0.8" width
then 48, 40, 28, 24 pins at 0.6"
then 24, 16, 8 pins at 0.3"
48, 64 pin ones are for the 68000

The pins that grab the chip are hard to see in these photos.
The AP ones use a spoon/duckbill shape to better grip each IC pin.
springs and hinges
The better ones use a spiral spring, metal hinge pin
and a piano hinge for a uniform grip of all pins.
The blue Archer (Radio Shack) one uses a plastic hinge as spring too.
other variations: the top connectors
3 styles:
  • nail head: individual clips won't slip off
  • smooth pins: connect entire row with a ribbon cable
  • flat ones: cheapest, easy to bend
    but individual clips won't slip off or swing around
Some are the same length on both sides.
Others have one side higher than the other
for clips or connectors to reach over each other
Some AP clips were sold under the 3M or Lafayette label.
I'm unsure who made the Archer Radio Shack one.
The blue 20 pin SOIC clip is by ITT Pomona

Another ancient breadboard in excellent condition:
SK-10 by E&L Instruments of Derby Connecticut, made in Israel!
A ceramic Z80A's on this SK-10 solid one piece breadboard, with 4 busses!
This is now sold by Global Specialties as the UBS-100
still with E&L markings on top with 64 tie points, making it the largest available!
EIC vs. Global breadboards
Admittedly, the Global Specialties "EXP" (Experimentor) breadboards (bottom) have fewer tie-points than similarly-sized E.I.C. brand breadboards (center, top) but it's one solid piece with edge channels that connect on all sides. Counting only the 10-across rows:
  • 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
More details about the EIC breadboards
  • 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
And another gotcha: on SOME breadboards, the side busses go all the way, others are spilt in the center WITHOUT ANY MARKINGS TO WARN YOU! I guess it's kinda implied by the subtly greater space between the center holes.
And accessories:
  • 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: a mail-order breadboard 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: note the subtle difference in spacing!)
  • NO edge clips or interlocks, only mounting holes to use more than one
  • Electronix Express is a Division of R.S.R. Electronics, Inc.
    but it looks like most of their breadboards have been upgraded
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?
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.
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
Niel Cherry (an IXR member) has this breadboard with gold contacts!
The bottom was covered over so we don't know the maker.

Some have totally yellowed, some not at all, some barely yellowed at the edges.
I'm unsure if it's anything about how & where I stored, them, etc.
Apropos of that: retr0bright is a clever solution for case yellowing.

other breadboard resources

Electronics Express has a good selection of breadboards by many makers, at great prices.

Abra electronics has the most complete selection I've found for breadboards: name-brand and their own (in fun colors, even clear and translucent red).
The brands offered:
PI Manufacturing Corp. has a wide selection and nice jumpers too.

I'm not the only one frustrated by breadboard variations

updated 19-April-2017