Whats this board? - Page 1
Forum section: electronics / general

author: pepelevamp
author_rank: Regular Contributor
timestamp: October 31, 2019, 06:34:22 pm
content: Just saw this on NZ's version of ebay called TradeMe. Anyone got some guesses as to what kind of board this is? Its in the vintage computing section, but it might not necessarily be computer / PC related.I have one or two ideas but I'd like to see what you lot thinkhttps://www.trademe.co.nz/computers/vintage/listing-2381126135.htm

author: jmelson
author_rank: Super Contributor
timestamp: October 31, 2019, 08:33:19 pm
content: The C106 components are SCRs.Jon

author: Cyberdragon
author_rank: Super Contributor
timestamp: November 01, 2019, 12:24:06 am
content: Quote from: jmelson on October 31, 2019, 08:33:19 pmNo, too new and the wrong package.These are (2S)C106 signal transistors.It appears to be from the late 60s to mid 70s and judging by the identical columns of components and use of lots of diodes (for logic) it appears to be a logic board out of something like a calulator or digital meter.

author: mengfei
author_rank: Regular Contributor
timestamp: November 01, 2019, 03:16:23 am
content: could be an IBM interace cardcheck these outhttps://vipclubmn.org/Artifacts.htmlhttp://www.righto.com/2015/03/a-database-of-sms-cards-technology.html

author: VK3DRB
author_rank: Super Contributor
timestamp: November 01, 2019, 01:39:09 pm
content: Quote from: mengfei on November 01, 2019, 03:16:23 amDefinitelyNOTan IBM interface card for four reasons:1. No IBM card soldered to gold tabs.2. Prior to the early 1908's, IBM used their own part numbering schemes of everything, including discrete semiconductors.3. Workmanship is generally poor. Wire-adds were never placed in such a haphazard way on IBM cards and there is no bevelling on the card connector edge.4. ALL IBM PCBAs and PCBs have the part numbers and usually the EC number on them as well.I worked for IBM for many years on a very wide range of equipment made from 1926 (ICT) until 1999, covering a broad range of technologies, from valves (vacuum tubes) right through to advanced VLSI. That includes IBM's SLT boards which are vaguely similar to the board shown here.It looks like a board out of an old adding machine, early impact printer or OEM tape drive. In any case, EMC was never a consideration!

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: November 01, 2019, 02:10:48 pm
content: Quote from: Cyberdragon on November 01, 2019, 12:24:06 amI'm afraid he's right, and the names are THxxx => thyristors... !https://pdf1.alldatasheet.com/datasheet-pdf/view/616889/NJSEMI/C106B1.htmlCould be the driver for an 8 pins dot matrix head? Of a very early DMP... ?

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 01, 2019, 03:13:45 pm
content: Yes, the C106B1 is an SCR that was available from several vendors. B1 is the 200V version.Mouser still holds a datasheet as well:https://www.mouser.com/ds/2/68/c106a1_series-534345.pdfCould it be some kind of Nixie tube driver?

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: November 01, 2019, 03:31:27 pm
content: Why are the traces soldered to the gold fingers on the edge connector? Why not just make them contiguous when laying out the board?

author: Syntax Error
author_rank: Frequent Contributor
timestamp: November 01, 2019, 09:12:25 pm
content: A longgggg time ago, I remember seeing circuits of this type, size and colour in our science class. Our teacher had a box of old circuits which he used to teach us the art of soldering and flux abuse. He was a former technician for the British General Post Office (now British Telelcom) and he'd obtain derelict exchange parts as teaching aids.Looking at the distribution of components, it's certainly a three or four channel 'something'. It also looks like the solder has been used to make the tracks more robust. I would start my Googling for vintage telephone exchange equipment. The card's form factor certainly fits in an environment that needs a fast change-out. The PCD may be obvious when we know where this came from.Maybe these are pulse or audio amplifiers? It would be cool if this was from something from a missile launcher or an early 1960's synthesizer, but without provenance, they're just 'vintage'.

author: pepelevamp
author_rank: Regular Contributor
timestamp: June 12, 2020, 01:27:22 pm
content: Thanks fellas. Sorry for the late reply. I'm looking at 'PCD' in the top of the board there. Taking into account what you're saying about possible vintage exchange gear maybe this is a 'Pulse Code Decoder' ?it just doesn't seem to have any blocks of logic that i can see anywhere. its all discrete stuff.If those are all thyristors is this an amplifier or switch of some kind? Power Control Device?Something to get smooth power into the rest of the phone system?

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: June 12, 2020, 01:35:35 pm
content: My old SD nixie counter has numerous SCR-based (actually 4-lead silicon controlled switches) counter cards for each display tube similar to what you've shown. I'm guessing a counter/driver card.

author: pepelevamp
author_rank: Regular Contributor
timestamp: June 12, 2020, 02:45:45 pm
content: Thats pretty cool. That sounds about right to me. Heh you know, even if thats not what it actually is - the fact that you could probably use the board to control a nixie is enough for me to consider the case closed. I like your signature about not getting old unless ya have stories.

author: duak
author_rank: Super Contributor
timestamp: June 13, 2020, 12:38:38 am
content: I count 8 SCRs so I propose a solenoid driver for a paper tape punch. 7 bit ASCII plus parity. Remex and Facit ring a bell.These things were also used on CNC machine tools to at least 1984. In the days before PCs one could edit a CNC program on the built in computer and then punch out a revised version if need be.

author: pepelevamp
author_rank: Regular Contributor
timestamp: June 14, 2020, 04:45:33 am
content: Quote from: duak on June 13, 2020, 12:38:38 amzomg maybe you are right. that never even occurred to me.