The 6529 Single Port Interface (SPI aka PIO) was an
integrated circuit
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...
made by
MOS Technology. It served as an I/O controller for the
6502 family of microprocessors, providing a single
8-bit
In computer architecture, 8-bit Integer (computer science), integers or other Data (computing), data units are those that are 8 bits wide (1 octet (computing), octet). Also, 8-bit central processing unit (CPU) and arithmetic logic unit (ALU) arc ...
digital
Digital usually refers to something using discrete digits, often binary digits.
Technology and computing Hardware
*Digital electronics, electronic circuits which operate using digital signals
**Digital camera, which captures and stores digital i ...
bidirectional
parallel
Parallel is a geometric term of location which may refer to:
Computing
* Parallel algorithm
* Parallel computing
* Parallel metaheuristic
* Parallel (software), a UNIX utility for running programs in parallel
* Parallel Sysplex, a cluster of IBM ...
I/O port. Unlike the more sophisticated
6522 VIA and
6526 CIA, it did not allow the data direction for each I/O line to be separately specified, nor did it support
serial I/O or contain any
timer capabilities. Because of this, it did not achieve widespread use.
6529 ICs were available in 1
MHz, 2 MHz, and 3 MHz versions. The
form factor was a
JEDEC-standard 20-pin
ceramic or
plastic DIP.
The 6529 differs from a 74(LS)639 bidirectional three-state/open-Collector-busdriver in that the 6529 has passive output pullups and power-on reset circuitry.
External links
MOS 6529 datasheetMOS 6529 datasheet (GIF format, zipped)
{{MOS Interface
MOS Technology integrated circuits
Input/output integrated circuits