[Dave Farquhar] takes a walk down memory lane about the Commodore 1600 VICModem, perhaps the first phone modem to sell for less than $100. Commodore, of course, was famous for making cheaper computers like the VIC20, the Commodore 64, and lower-cost peripherals like disk drives. But how did they hit the $100 price point with the modem when competing 300 baud modems sold for at least twice that, and a 1200 baud unit would set you back at least $600?

First, Commodore didn’t handle the design themselves. Instead, they outsourced to Anchor Automation, a well-known modem manufacturer. It used a Motorola MC14412 modem on a chip, along with six other chips. The chip could, in theory, do 600 baud, but the modem was rated for 300. But it did make some interesting design choices.

Old-school modems were not allowed to connect to the phone lines directly, so you dialed the phone number and then shoved the handset into some padded cups known as an acoustic coupler that placed a microphone next to the phone speaker and a speaker next to the phone microphone. Modern modems didn’t have this problem (thanks, in part, to Tom Carter), and the VICModem also connected directly. But to save money, it couldn’t dial the phone for you. The idea was you’d dial the phone like you would with an old acoustic modem and then pull the handset cord and plug it into the modem yourself.

There was a problem. In those days, old phones didn’t always have a plug on the handset. Ironically, according to [Dave], the company bought phones to bundle with the modem in Canada only to find out the phones they bought had hard-wired handsets and were not usable. Not only that, if the phones had been the right kind, they would have been illegal in Canada at that time since the phone rules prohibited modular jacks for the handset.

To fix the problem, they also bundled the VIC-1605, which was essentially a Y cable for the phone. You plugged it into the wall, and then plugged the phone into an RJ-11 and the modem into an RJ-9.

There were other cost savings, too. There was a switch that determined if you were originating a call or receiving one, for example. A great example of how to design something as cheaply as possible, other than the faux pas with the phone connectors.

These days, it is hard to find a modem, but even if you do remember them fondly, it is surprising how old they really are and how little you needed to make a low-rate acoustic modem.