Echoes of an Old Modem
A few days ago, I posted a photo on social media showing the configuration of what was my first computer, purchased way back in December 1992. I haven’t connected it yet, mainly because I have to reinstall the 40 MB hard drive! And, above all, I have to check everything, change the battery on the motherboard, and take care every step of the way because when a machine like this has been out of use for so many years, bad things tend to happen when you plug it back in. Someday I’ll talk about this old computer, which now looks just like it does in the photo.
The thing is, back in ’98, I think, I upgraded the machine with a modem to access the Internet. It was incredibly slow, because in addition to connection problems, a 386 wasn’t exactly ideal for surfing the web. Shortly after that, I switched to another computer and this one was left in the storage room. I had been using the Internet on the computers at the University of Valladolid (Spain) since 1993, but accessing it from home was a special challenge. The connection, via a conventional telephone line, would be cut off if someone called or if I made a call. The rates were expensive, and we used to buy vouchers in the form of cards to use monthly during certain time slots, for example, after 6:00 p.m. It was fine for emails and simple tasks, but when it came to accessing the primitive web or downloading things via FTP, it could take forever. At six o’clock, you would connect, already with a list of links or resources to download, and you could go out for a walk because, surely, when you returned, it would still be loading… that is, if the line hadn’t been cut! The modem in question is the one I just photographed.
This is an external modem, manufactured in Spain by Vayris, which was typical of the late 1990s, with data, fax, and voice capabilities, plus Internet access. In other words, a classic PSTN modem with standard V.90 “56K” speed (it could theoretically reach up to 56,000 bits/s downstream and 33,600 bits/s upstream). It connected to the PC via an RS-232 serial port and, although it had a voice and hands-free system, to which you could even connect an answering machine, I never used those functions.
In reality, the 56K speed was usually far off, reaching 49,000 bps at best. The most exciting moment was when you turned on the little gadget and it started making sounds to connect. The sound pattern was typical, so if one day it didn’t sound the same, you knew there were problems with the line or some other connection issue. Here is the sound that marked a generation.
The front panel has some very cute little lights that flashed depending on the data transfer or line status.
The lights showed the classic signal or status states for this type of device:
RS/CS: RTS/CTS (hardware flow control).
CD: Carrier Detect (there is a carrier/connection with the other modem).
OH: Off Hook (the line has been “picked up”).
RD/SD: data received or sent.
TR: DTR (the PC “says” it is ready).
MR: DSR (the modem “says” it is ready).
The “56K” was not symmetrical; the interesting thing about V.90 was that it used PCM downstream (from the ISP, which was in digital mode) and V.34 modulation upstream. That’s why the upload speed was only 33.6. Reaching 56,000, as I said, was out of the question. In many places there was a limit of around 53.3 kbps due to regulatory restrictions on power in the telephone network. That’s why many people only reached 49 or 50k on good days. Maybe one day I’ll try it again, somehow.
