Keyboard
The VIC-20's keyboard largely conforms to the QWERTY standard, however it differs from modern computer keyboards in several aspects:
- There is no ESCAPE key, although a left pointing arrow in the upper left corner of the keyboard can be made to function this way in software.
- There is no cursor "T" pad. Instead, there are two cursor control keys. One for UP/DOWN and another for LEFT/RIGHT. Pressing a cursor key with or without the SHIFT key held down toggles that key's function.
- There are no ALT keys.
- A Commodore logo key (also called the "CBM" or "Chickenhead" key) enables special functions when depressed simultaneously with other keys. Some of these functions are: toggle Upper/Lower case characters and enable PETSCII graphics).
- A RUN/STOP key on the VIC-20 can be used to start and stop the execution of BASIC programs.
The keyboards used in VIC-20 computers were manufactured for Commodore by Matsushita Corporation of Japan. Those used on the very first VIC-20s were almost completely flat-topped and identical in shape to that of Commodore's PET computer (however, on the VIC-20 the PET's number pad was replaced by four wide function keys). The keyboards on later VIC-20s were manufactured with slightly concave tops. The concavity of the “F” and “J” keys was slightly more prominent to provide tactile feedback for touch-typists seeking the “home” position.
There are several variations of the VIC-20's keyboard:
- English standard version.
- Japanese version (seen on VIC-1001) with kana (Japanese characters) and a Yen currency symbol.
- Scandinavian keyboard (with Scandinavian letters).
The VIC-20 keyboard is electronically and physically compatible with that used in the Commodore 16 and Commodore 64 model computers (although the C16 keyboard has some keys labelled differently). The keyboard of the VIC-20 connects to a row of pins on the VIC-20 motherboard by means of a long plastic female connector. This connector carries ROW and COLUMN signals from the keyboard matrix.
Internally there are graphite, carbon coated, spring loaded plungers under each key. When a key is depressed the plunger touches a corresponding metal contact on a printed circuit board, thereby sending a signal to the CPU. Some very early VIC-20 keyboards seemed to have been assembled using the same printed circuit boards used in PET computers. In these, the electrical contacts for the PET's number pad are still present, but as the VIC-20 has function keys instead of a number-pad, the unused contacts are covered over with electrical tape.
Keyboard input/output is controlled by one of the VIC-20's VIA chips. If VIA #2 is bad, keyboard problems (such as every other key not responding) will manifest themselves.
The VIC-20 keyboard has all of the PETSCII graphic characters printed onto the front face of each of the keys (the side facing the user). Holding down either the COMMODORE or SHIFT key while pressing a PETSCII graphic key will cause that symbol to appear on-screen.
Over the manufacturing lifespan of the VIC-20, three different fonts were used to print the letters and symbols on the key-tops:
- Earliest VIC-20 keyboards used the Microgramma Extended font which was also used on PET computer keyboards.
- Second generation keyboards used the Eurostile font which was less-bold, but still square in shape.
- Third generation keyboards used a tall, thin font similar to Helvetica Narrow. This font also was used for the first Commodore 64 (breadbox style) computers.
The early "PET" style keyboard was lower in profile when compared with the two later VIC-20 keyboards.
Most of the VIC-20's keys were moulded in dark-brown plastic, with the function keys being a lighter brown/mustard. However, some very late production production VIC-20s were shipped with Commodore 64 grey coloured function keys. It also seems that a few extremely early Commodore 64 prototypes and production-line computers were assembled using VIC-20 coloured brown/mustard function keys.
