MOS Technology TED
The 7360 Text Editing Device (TED) was an integrated circuit made by MOS Technology, Inc. It was a video chip that also contained sound generation hardware, DRAM refresh circuitry, interval timers, and keyboard input handling. It was designed for the Commodore Plus/4 and 16. Packaging consisted of a JEDEC-standard 48-pin DIP.
Video capabilities
The video capabilities provided by the TED were largely a subset of those in the VIC-II. The TED supported five video modes:
- Text mode of 40×25 characters with 8×8 pixels
- Multicolor text (4×8 pixels per character, double pixel width in x direction)
- Extended background color mode (8×8 pixels per character)
- Multicolor Graphics 160×200 pixels
- Hi-Res Graphics 320×200 pixels
These were largely unchanged from the corresponding VIC-II modes aside from different register and memory mapping (see the article on the VIC-II for information on graphics modes). However, the TED lacked the sprite capabilities of the VIC-II, and so game animation had to be done with programmable characters like on the VIC-20. This tended to restrict the graphics of C16/Plus 4 games versus the C64. The TED did include two features that the VIC-II lacked: luminance control and blinking text. Fifteen of its 16 colors (black being the exception) could be assigned one of 8 luminance values, thus making the TED capable of displaying a far wider array of colors than the VIC-II. The full palette of 121 colors is shown below.[1]
hue / luminance 0 1 2 3 4 5 6 7 1 — black 1,0 1,1 1,2 1,3 1,4 1,5 1,6 1,7 2 — white 2,0 2,1 2,2 2,3 2,4 2,5 2,6 2,7 3 — red 3,0 3,1 3,2 3,3 3,4 3,5 3,6 3,7 4 — cyan 4,0 4,1 4,2 4,3 4,4 4,5 4,6 4,7 5 — purple 5,0 5,1 5,2 5,3 5,4 5,5 5,6 5,7 6 — green 6,0 6,1 6,2 6,3 6,4 6,5 6,6 6,7 7 — blue 7,0 7,1 7,2 7,3 7,4 7,5 7,6 7,7 8 — yellow 8,0 8,1 8,2 8,3 8,4 8,5 8,6 8,7 9 — orange 9,0 9,1 9,2 9,3 9,4 9,5 9,6 9,7 10 — brown 10,0 10,1 10,2 10,3 10,4 10,5 10,6 10,7 11 — yellow-green 11,0 11,1 11,2 11,3 11,4 11,5 11,6 11,7 12 — pink 12,0 12,1 12,2 12,3 12,4 12,5 12,6 12,7 13 — blue-green 13,0 13,1 13,2 13,3 13,4 13,5 13,6 13,7 14 — light blue 14,0 14,1 14,2 14,3 14,4 14,5 14,6 14,7 15 — dark blue 15,0 15,1 15,2 15,3 15,4 15,5 15,6 15,7 16 — light green 16,0 16,1 16,2 16,3 16,4 16,5 16,6 16,7
Sound capabilities
The TED featured a simple tone generator that produced two channels of audio. The first channel produced a square wave, and the second could produce either a square wave or white noise. This tone generator was designed for business applications, and did not provide the extensive sound features found in the SID chip.
Other features
The TED includes three 16-bit interval timers, which consist of down counters operating at the master clock frequency. They can generate IRQs on underflow. The chip also contains an I/O port, which is used on the Plus/4 and 16 to scan the keyboard and joystick. In addition, it handles bank switching, used by the operating system to maximize the amount of RAM available to Commodore BASIC.
An undesirable feature of the chip is its well-known tendency to destroy itself though overheating. To preserve a computer which employs this chip in working order, it is recommended to improve its cooling.