Just for fun, you want to ID this? - Page 1
Forum section: electronics / general

author: Rick Law
author_rank: Super Contributor
timestamp: April 18, 2013, 09:24:06 pm
content: I was looking for my 40 year old breadboard and associated stuff, it turned into an electronics-archeology field trip in my basement. Looking at old stuff is kind of fun. I found this old board.Forfun, do you want to speculate what this is? This board is probably 25 years old.(I blanked out the product/manufacturer ID in 3 parts of the board so you don’t see the answer)

author: baljemmett
author_rank: Unknown
timestamp: April 18, 2013, 09:31:33 pm
content: Quote from: Rick Law on April 18, 2013, 09:24:06 pmMy guess would be a modem of some description, although I'm wondering why it would have two phone jacks -- passthrough, I suppose, since they look like they're bussed rather than two lines.(I'd also guess at Hayes as the manufacturer!)

author: c4757p
author_rank: Super Contributor
timestamp: April 18, 2013, 09:33:16 pm
content: Yep. It's got two phone jacks apparently in parallel, a UART, a relay and a speaker. It's got to be a modem.

author: Unknown
author_rank: Unknown
timestamp: April 18, 2013, 09:38:37 pm
content: Yes, the same here but it seems one hell a lot of IC's although, if it also has a dial-up too ?

author: free_electron
author_rank: Super Contributor
timestamp: April 18, 2013, 09:46:13 pm
content: 12 baud modem. made in the usa (c) 1983. using a romless z8.. why did you blank out the rom ? ah, it must be mask rom and probably has the name of the firmware writer on it. Rockwell. no , can't be . it would have rockwell chips. The board layout style and font are not IBM ... must be .. US robotics then

author: baljemmett
author_rank: Unknown
timestamp: April 18, 2013, 09:52:52 pm
content: Quote from: vlf3 on April 18, 2013, 09:38:37 pmIt's an 8-bit ISA card by the looks of it, so it's going to be from a rather less-integrated time -- a lot of chips bearing 1984 date codes (free_electron suggests 1983 for the copyright date; I can't quite read it but can squint and make it look like '83 indeed), so there you go. Entirely in keeping with cards of that era; I remember seeing a 3Com EtherLink III (with a nice big ASIC) for the first time and being amazed as how empty it was compared to the EtherLink II (which was absolutely festooned with chips).

author: Rick Law
author_rank: Super Contributor
timestamp: April 18, 2013, 10:33:36 pm
content: Hats off to you guys, you guys are good. This is no challenge to you at all!I am really impressed! You guys ID it in moments.It is a "Hayes Smart Modem 1200B". Indeed an 8bit ISA card used in my Zenith Z100 PC-compatible. Attached is the full photo (before I did the blank-out). Next to the serial number, the product ID and copyright said 1983. Same on the ROM with the HAYES trademark and company logo.With so many IC's on it and workmanship, I think it must have cost me a mint back then. I think I am going to desolder those IC's, resistors and capacitors. I've got to extract some residual value out of it. The few OpAmps I can reuse, loads of resistors, capacitors...Speaking of spending a mint, I wish I found my HP35 and my HP45 instead of this modem. I regret selling my SOL-20; it took me almost over a week to build. It worked like a charm. Those three things I miss. This modem, I will get some use out of the resistors... Resistance is futile; you resistors will be assimilated into my parts box.

author: c4757p
author_rank: Super Contributor
timestamp: April 18, 2013, 10:35:40 pm
content: Why the hell would you harvest resistors??They're like 5 cents each and they're all cut to size on that board!

author: MacAttak
author_rank: Unknown
timestamp: April 18, 2013, 11:50:47 pm
content: Here's a cool bit of engineering history to go along with your find.Dale Heatherington was the engineer who designed that modem (as well as everything before it). He is a local resident still here in Atlanta - these days he builds robots and is a member in the Atlanta Hobby Robots Club, where as I understand it, he usually wins the battle competitionshttp://www.wa4dsy.com/robot/home/about

author: ve7xen
author_rank: Super Contributor
timestamp: April 19, 2013, 12:28:34 am
content: Quote from: baljemmett on April 18, 2013, 09:31:33 pmYou must be from a time after modems were in wide use.Don't think I've ever seen one without a passthrough for connecting a phone/fax.

author: xrunner
author_rank: Super Contributor
timestamp: April 19, 2013, 12:30:59 am
content: Quote from: Rick Law on April 18, 2013, 10:33:36 pmI remember back in the day having to keep track of what cards were using what IRQs. I used to keep a text file on each computer to remind me of how many were left to be used.

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: April 19, 2013, 01:52:11 am
content: AHH the screaching DEE DAHH DOO CRRRRRRR of the modem.I don't miss it, the irq conflicts, or taking two days to download a 1 meg file.

author: TerraHertz
author_rank: Super Contributor
timestamp: April 19, 2013, 10:48:30 am
content: Quote from: Rick Law on April 18, 2013, 10:33:36 pmYears after buying my HP45 in uni, I nearly sold it. So glad I didn't. Still use it.You know it's very easy to buy those old HP calculators?http://www.ebay.com/itm/Vintage-HP-45-Calculator-with-Extras-still-Working-Great-/251262078330?pt=Vintage_Electronics_R2&hash=item3a80630d7a

author: Gall
author_rank: Frequent Contributor
timestamp: April 19, 2013, 11:10:15 am
content: Oops, I'm late...A 8-bit ISA card. Ok.A really old card - discrete logic.A transformer? Hm. Capacitors near the jacks. This should have been connected to something that works at higher voltage, a phone line probably.Jacks? Phone Jacks?A speaker at the left?A board that connects to phone line and has a speaker? MODEM, of course!

author: baljemmett
author_rank: Unknown
timestamp: April 19, 2013, 08:14:18 pm
content: Quote from: ve7xen on April 19, 2013, 12:28:34 amNo, not really - it's just that only one of mine had a passthrough jack, that I can recall, and that was a voice modem so I presumed it was there mainly to support the voice features. The IBM model currently hooked up to the AS/400 in the garage, and the USR card in my old XT, don't have a second jack to the best of my recollection!The difference might be that British telephones don't terminate in RJ11s, so a splitter in the BT socket probably makes more sense than the little pigtail adapter that my Hayes needed to connect a phone to the passthrough.