Modem 300 [Model 1660]
The Commodore 1660, also known as the “Modem/300”, is Commodore’s first full-featured modem: It connects directly to the phone line and supports pulse and tone dialing for 300 baud duplex connections.
Historical Context:
| Year | Name | Model | Description |
|---|---|---|---|
| 1982 | VICMODEM | 1600 | connected to phone’s handset connector; manual dialing through phone; Motorola MC14412 |
| 1982 | AUTOMODEM | 1650 | connected to phone line, pulse dialing in software; Motorola MC14412 |
| 1985 | MODEM/300 | 1660 | added tone dialing support by feeding SID output into modem; Texas Instruments TMS99532A |
| 1987 | MODEM/1200 | 1670 | Hayes command set; pulse and tone dialing in hardware; 300/1200 baud support; U.S. Robotics chipset |
On the back, there are:
- two phone line connectors. “LINE” is connected to the telephone network, and an existing telephone can be connected to the “PHONE” line.
- an RCA audio connector. The circuitry in the modem only does the 300 baud data transmission part once the telephone connection is established – tone dialing is done by using software to generate the audio using the C64’s sound chip, which is looped into this connector! (Pulse dialing is also done in software, by timing on-hook and off-hook events.)
The modem comes with one phone cable. And there are two cables that connect the C64’s audio output to the modem:
- The DIN to RCA cable takes the audio signal from the C64/C128 AV connector. It is used if the C64 is connected to a TV through the RF connector, so the AV connector is available.
- The RCA Y-cable takes the audio signal from the monitor cable. This is used if the C64 is connected to a monitor using the AV connector.
Software (click label to download .d64 disk image):
Side A:
Side B:
Modem 300 manual
additional material
