Guess that makes me a little older than you. I first encountered acoustical couplers in college in the early 70s (73 74?). Someone left a teletype in the dorm. One of my friends knew the phone number to a PDP-8 at the school computer center. There were three us that stayed up all night taking turns writing programs on it in BASIC. We tied into the PDP-8 at 110 baud. At the end of my turn, I would turn the paper punch on and type LIST. Not only did it print out a listing, but it punched a tape. The next user typed NEW to clear my program. He then loaded his paper tape and as it read the tape it would send lines of BASIC to the PDP-8 the same as if he had typed it. A new listing was also generated. My program was a nuclear war game which was pretty primitive, but fun.
Later, I worked for a company in Minneapolis that had a DEC LSI-11 with an auto-answer modem connected. They also had a Lear Siegler dumb terminal and an acoustical coupler modem. My boss would allow me to take the terminal and modem home so I could tie into the DEC LSI-11. At least now we were up to 300 baud. I wrote a BASIC game on it called, Space Maze. I documented it and published it in the 1979 issue of Creative Computing. Now that I'm retired and have both a NEC PC-8201A (that I have had since the early 80s) and a TRS-80 Model 100 (purchased this year from eBay), I'm planning on rehosting this game as well as other games I had published in Creative Computing to the these machines. I'll plan on sharing the results with this group (somehow) when I'm successful. Lloyd -----Original Message----- From: M100 <[email protected]> On Behalf Of Brian K. White Sent: Tuesday, May 18, 2021 5:02 PM To: [email protected] Subject: Re: [M100] Good Times. Anyone have a Shilling? That's what I remembered too. But acoustic couplers were just going away when I was in grade school so I only ever used them a few times. Maybe it could theoretically download at 1200, at the expense of going half duplex or reducing upload to just 75, and assuming the software on the 100 is optimized and does not update the screen while downloading. https://upload.wikimedia.org/wikipedia/commons/f/f2/Acoustic_coupler-IMG_7282-7283.jpg That even looks very similar to the one in the video. The cable is different and one of the cups looks a little different, but that does still look very similar. Maybe it was a case that, just because it says 1200 on the box does not mean it can ever actually do it in real life, and maybe 300 was the effective limit and it could only go faster in theory. Or maybe it was just the full duplex limit, since you're not going to actually do anything else but full duplex in any normal situation. You can't go over 600 in a normal situation on a 100 anyway with screen updates even via direct null-modem. And I bet the 1200 over acoustic coupler over a phone line requires a perfect phone line, which I doubt a moving train in the 80's had. But, the 100 can do 1200, in theory, with optimized software, and the modem at least claims it can do it, in theory. -- bkw On 5/18/21 3:50 PM, [email protected] wrote: > If memory serves me correct, I think the acoustical coupler modems were > limited to 300 baud? > > I also remember the old Model 33 teletypes were either 110 baud or 300 baud > and sometimes only 110 baud. > > I'm pretty sure he wasn't going for speed using an acoustical coupler modem. > Great video! Brings back great memories. > > Lloyd > > -----Original Message----- > From: M100 <[email protected]> On Behalf Of Josh Malone > Sent: Tuesday, May 18, 2021 2:42 PM > To: [email protected] > Subject: Re: [M100] Good Times. Anyone have a Shilling? > > This was a U.K. model, presumably. Did those get released w/ internal modems? > I thought Tandy pulled the modem from the UK model cuz of BT certs. > > On Tue, May 18, 2021 at 3:24 PM you got me <[email protected]> wrote: >> >> I think an external modem had a higher speed than the one built into the >> m100. >> ________________________________ >> From: M100 <[email protected]> on behalf of Brian K. >> White <[email protected]> >> Sent: Tuesday, May 18, 2021 7:13 PM >> To: [email protected] <[email protected]> >> Subject: Re: [M100] Good Times. Anyone have a Shilling? >> >> On 5/18/21 10:28 AM, ~Art wrote: >>> >>> Just saw this on the Tweeter... >>> >>> https://twitter.com/i/status/1394004961571352580 >>> >>> >>> Art >>> >> >> >> ... using an external modem on the rs-232 port, wasting the one >> already built right into the machine. Philistine! >> >> That neat all-one-piece one is more photogenic than the two loose >> black rubber cups and wires though, even if they are smaller, lighter, >> and don't unnecessarily consume a useful port. >> >> Or maybe the international model didn't have a modem? I think the >> Olivetti is like that, only the NA model has a modem built-in. >> >> -- >> bkw > -- bkw
