Motorola 6800
The Motorola 6800 is an 8-bit microprocessor introduced in 1974.
![](http://w140.com/tekwiki/images/thumb/a/a5/MC6800.jpg/350px-MC6800.jpg)
It requires a +5 V supply only (generating bias voltages on chip) and came initially in 40-pin DIL packages. The 6800 has non-multiplexed data (8 bit) and address (16 bit) buses, and requires an external non-overlapping two-phase 0.1 − 1 MHz clock (later versions from 1976 on up to 2 MHz).
The 6802, introduced in 1977, includes 128 bytes RAM and an internal clock oscillator. The 6808 is the same without RAM.
![](http://w140.com/tekwiki/images/1/10/Motorola_6800.png)
The 68HC11, introduced in 1984, is an upward-compatible microcontroller that adds a second index register, 8x8 multiply and 16/16 divide instructions, as well as a range of 16-bit instructions that treat A and B as a combined 16-bit accumulator. On-chip peripherals include timers, parallel ports, A/D, SPI and UART.