In 1977, at age 16, I went to work for Noakes Data Communications in Irving Texas.
We built an 8080 industrial computer, made modems, and repaired lots of comm gear. RS232 was what we lived and breathed. And back then almost all the control signals were actually used, not just jumpered or ignored. I remember thinking at the time that the bipolar signal levels were such a waste of time for office and personal computers. They should have just gone to a TTL version for everything local like printers, and modems, and keyboards and terminals. Back then we had to use 1488 and 1489 level converters with +/-12v power supplies. Such a costly hassle. Of course, many years later we got MAX232 with 4 .1uf caps and 5v which solved the cost problem. I still have my blue breakout box from that year. It cost something like $300 at the time which was the price of a used car 🙂 I documented the company here: https://www.rogerarrick.com/noakes/ [https://www.rogerarrick.com/noakes/noakes_label.png]<https://www.rogerarrick.com/noakes/> Noakes Data Communications - Irving Texas - 1970s-1980s<https://www.rogerarrick.com/noakes/> Noakes Data Communications. 1 May 2023. Click images for larger view 1973-1987 Noakes Data Communications 3330 Stovall St, Irving, TX 75061 214-790-1050 www.rogerarrick.com -- Roger Arrick -- Tyler, Texas, USA -- [email protected] -- ________________________________ From: Doug Jackson via cctalk <[email protected]> Sent: Friday, January 31, 2025 8:15 PM To: General Discussion: On-Topic and Off-Topic Posts <[email protected]> Cc: Steve Lewis <[email protected]>; Doug Jackson <[email protected]> Subject: [cctalk] Re: RS232 then and now I own my entire working career to some random happenings as a kid with interfacing equipment to IBM PC clones using RS232. As a late teenager I used to hang out at the local computer store who sold Toshiba gear. I had a knack for making cables that allowed them to connect brother printers using RS232. One day a person from the local university dropped in asking if they knew anybody who could help interface a piece of lab gear to their Toshiba PC... I got recommended.. Then I helped to write the software to do the analysis work for them... That was in about 1986.. and here we are in 2025 some 40 years later... Remember 2 to 3 3 to 2 7 to 7 4, 5 to 6 6 to 4, 5 8 to 20 And 20 to 8... And if that didn't work. Just tie those pesky handshaking inputs to their nearest output and use software handshaking 😜... Built a career on that.. I cringe a little now I understand the intent of the signals. Doug On Fri, 31 Jan 2025, 7:20 pm Steve Lewis via cctalk, <[email protected]> wrote: > Hey all! So, I've found myself studying up on RS-232 this year for a few > reasons. > > I'm mulling over doing an RS232 themed talk at June VCF. Not a super > exciting topic, but I do think that RS232 has an interesting history: In > the SAGE relationship, and as a follow up to (essentially) prior telegraph > communication. > > From what I've read, "50 baud" was a kind of an initial goal to beat, since > that's what the top telegraph operators could achieve (in small burst, > probably not all day). And those operators did have to also deal with > things like start/stop "bits". Maybe it wasn't an intentional goal, but > just that it establishes why "50 baud" is generally the lowest we ever see > mentioned (or, if you go slower than that, might as well use the older > tech). > > Then 75/110/130 baud to have digital-systems interoperate with classic > mechanical teletypes. Going any faster and those systems jam up or > overheat? These weren't yet called "serial ports", so I'm not sure what a > late 50s system would even call their equipment that facilitate this data > exchange (since I'm not sure what kind of crystal-clock they even had > yet). > > Then, was it the SAGE program that demonstrated the idea of doing this kind > of data exchange across copper phone lines? That is, the idea of computers > collaborating not just in a room, but across long distances (miles)? And > doing so by using an audio tone presentation? (they settled on around > 3100MHz, which ended up translating to 300 baud? hence, that's basically > why the first digital to digital system data exchange settled on that baud > rate, which was reliable on both 50 and 60Hz power systems, and > meaningfully faster than prior 110 baud - so a good milestone to turn it > into a product, which was the Bell Model 103?). > > I couldn't find much details (like a manual) on the Bell 101 equipment > (anyone seen one or have a manual?). But I did find the Bell 103 manual - > the photo of its innards is grainy, so I don't understand how the Bell 103 > did 300 baud without a UART (and one of the pinout lines I see did run > power, so not sure if that's-yet RS232 or not; I know RS232 was evolving > right at that same time circa 1962). I've about the 1970ish TR1402 > initial DIP UART, with anything prior being an experiment (like a full > board concept by DEC). > > I know from 1962, both RS232 and ASCII standards still took maybe another > decade to really gain traction as standards (at least, from what I've > read). Getting the world to comply with any standard always takes a lot of > effort (for a practical reason of everyone still having invested in the > older tooling that was still functional). But it's interesting how those > two standards are still in use (not in their original form, but least the > 1967 revisions) - extending from Baudot.and late 1800s-tech on telegraphs. > > Does anyone know of any grocery stories using RS232 in the 1960s? I think > barcode scanning was just introduced in that era. I can just imagine a > smart grocery store owner, in the backroom programming their minicomputer > for payroll and inventory management. In FORTRAN and without a CRT? > Actually, in the 60s, I think included software would be negotiated with > the provider of the computer (well, I'm not sure how that differed between > minis and mainframes). > > I know early microcomputers used RS232 for keyboards (1974-1976 era). The > IBM PC keyboard is essentially another form of serial. > > Well, sorry for the rambling - have other RS232 related questions, but > first wanted to focus on the historical aspects (and see if I'm somewhat on > the right track at least). > > -Steve >
