The Commodore 16 is a home computer made by Commodore International, released in 1984 and intended to be an entry-level computer to replace the VIC-20.
The Commodore 16 (C16) belong to the same family as the higher-end Plus/4 and are internally very similar to it (albeit with less RAM – 16 rather than 64 KB – and lacking the Plus/4’s user port and integrated office suite). As a result, software is generally compatible among all three provided it can fit within the C16’s smaller RAM and does not utilize the user port on the Plus/4.
While the C16 was a failure on the US market, it enjoyed some success in certain European countries and in Mexico.
Outwardly the C16 resembles the VIC-20 and the C64, but with a dark-gray case and light-gray keys. The keyboard layout differs slightly from the earlier models, adding an escape key and four cursor keys replacing the shifted-key arrangement the C-64 and VIC inherited from the PET series. Performance-wise located between the VIC-20 and 64, it has 16 kilobytes of RAM with 12 KB available to its built-in BASIC interpreter, and a new sound and video chipset offering a palette of 121 colors, the TED (better than the VIC used in the VIC-20, but lacking the sprite capability of the VIC-II and advanced sound capabilities of the SID, both used in the C64). The ROM resident BASIC 3.5, however, is more powerful than the VIC-20’s and C64’s BASIC 2.0, in that it has commands for sound and bitmapped graphics (320×200 pixels), as well as simple program tracing/debugging.
From a practical user’s point of view, three tangible features the C16 lacks are a modem port and VIC-20/C64-compatible Datasette and game ports. Commodore sold a C16-family-specific Datassette (the Commodore 1531) and joysticks, but third-party converters to allow the use of the abundant, and hence much less expensive, VIC-20/C64-type units soon appeared. The official reason for changing the joystick ports was to reduce RF interference. The C16’s serial port (Commodore’s proprietary “serial CBM-488 bus”, no relation to RS-232 and the like) was the same as that of the VIC-20 and Commodore 64, which meant that printers and disk drives, at least, were interchangeable with the older machines. Partially for cost reasons, the user port, designed for modems and other devices, was omitted from the C16 (although the connections for it were still present on the system board). Despite costing less than the Plus/4, the C16’s keyboard was higher quality and easier to type on.
The Commodore 1530 (C2N) Datasette, later also Datassette (a portmanteau of data and cassette) is Commodore’s dedicated magnetic tape data storage device. Using compact cassettes as the storage medium, it provided inexpensive storage to Commodore’s 8-bit home/personal computers, notably the PET, VIC-20, and C64. A physically similar model, Commodore 1531, was made for the Commodore 16 and Plus/4 series computers.
Typical compact cassette interfaces of the late 1970s used a small interface in the computer to convert digital data to and from analog tones. The interface was then connected to the cassette deck using normal sound wiring like RCA jacks or 3.5mm phone jacks. This sort of system was used on the Apple II and Color Computer, as well as many S-100 bus systems, and allowed them to be used with any cassette player with suitable connections.
In the Datasette, instead of writing two tones to tape to indicate bits, patterns of square waves are used including a parity bit. Programs are written twice to tape for error correction; if an error is detected when reading the first recording, the computer corrects it with data from the second. The Datasette has built-in analog to digital converters and audio filters to convert the computer’s digital data into analog sound and vice versa. Connection to the computer is done via a proprietary edge connector (Commodore 1530) or mini-DIN connector (Commodore 1531). The absence of recordable audio signals on this interface made the Datasette and clones the only cassette recorders usable with Commodore computers, until aftermarket converters made the use of ordinary recorders possible.
Because of its digital format the Datasette is both more reliable than other data cassette systems and very slow, transferring data at around 50 bytes per second; even the very slow Commodore 1541 floppy drive is much faster. After the Datasette’s launch, however, special turbo tape software appeared, providing much faster tape operation (loading and saving). Such software was integrated into most commercial prerecorded applications (mostly games), as well as being available separately for loading and saving the users’ homemade programs and data. These programs were only widely used in Europe, as the US market had long since moved onto disks.