6850

Asincronous Communications Interface Adapter (ACIA)

Cross-Reference

BRAND	TAG	NUMBER	CLOCK	MARKINGS
Altera	A	6850	1.0 MHz	A6850
Gould	S	6850	1.0 MHz	S6850
Gould	S	68A50	1.5 MHz	S68A50
Gould	S	68B50	2.0 MHz	S68B50
Motorola	MC	6850	1.0 MHz	MC6850
Motorola	MC	68A50	1.5 MHz	MC68A50
Motorola	MC	68B50	2.0 MHz	MC68B50

Pinout

       DIP24-600mil
         +--\/--+
     Vss |1   24| *CTS
 Rx DATA |2   23| *DCD
  Rx CLK |3   22| D0
  Tx CLK |4   21| D1
    *RTS |5   20| D2
 Tx DATA |6   19| D3
    *IRQ |7   18| D4
     CS0 |8   17| D5
    *CS2 |9   16| D6
     CS1 |10  15| D7
      RS |11  14| E
     Vcc |12  13| R/*W
         +------+

Frequency

Set reader to FREQ, put black probe to GND, red probe to 3,4 to measure CPU clock

External links

"6809 support chips" page on CPU-World

Files

• 
  A6850 Datasheet
• 
  MC6850 Datasheet
• 
  S6850 Datasheet