Signetics 82S107
The Signetics 82S107 is a field-programmable logic array monolithic integrated circuit ("Field Programmable ROM patch" in the manufacturer's literature) with tristate outputs, in a 28 pin DIL package.
The device is organized as 48 words by 8 bits, addressed via a 16 bit programmable address comparator. Each word can be assigned a unique address within a 64K range by programming the comparator inputs High, Low, or Don't care via True/Complement input buffers. The contents of each word are also programmable, and are enabled to the outputs only when a programmed address is detected, which causes the Flag output to go Low.
A typical use is to accommodate field patches to code delivered in mask ROMs. On program addresses matching a programmed pattern in the 82S107, the flag output disables the mask ROM and enables replacement code, typically stored in a small EPROM, with lower bits of the address supplied from the 82S07's outputs.
Some instruments using part Signetics 82S107
| Instrument | Manufacturer | Class | Model | Description | Introduced |
|---|---|---|---|---|---|
| 4052 | Tektronix | Computer | 4052 | Graphics-capable desktop microcomputer | 1978 |
| 7854 | Tektronix | Oscilloscope | 7854 | 400 MHz waveform-processing scope | 1980 |
| FG5010 | Tektronix | Plug-in | FG5010 | 20 MHz function generator | 1982 |