Changes
== Usage in CPC ==
Used by [[CPCI_RS232_Interface|CPCI]] (DIY german magazine CPC Schneider International):
F8DCh CPCI Serial Interface MC6850 Control/Status Register (R/W)
F8DDh CPCI Serial Interface MC6850 Data Register (R/W)
IRQ pin is not connected (can be read only by software, in Status.Bit7)
Used by [[KDS_Electronics_Serial_InterfaceKDS Electronics Serial Interface]]:
FBECh KDS RS232 6850 (reversed-bit-order) Control (W)
FBEDh KDS RS232 6850 (reversed-bit-order) TX Data (W)
Caution: KDS has wired the 6850 chip's data bus incorrectly: D7 is D0,
D6 is D1, etc. (so the bit order must be reversed by software).
Input CLK is 2MHz with variable 16bit divider (programmable [[8253 chip]])
Used by [[AMSSIO]] (DIY by Martin Zacho):
FBF0h AMSSIO Serial Interface MC6850 Control/Status Register (R/W)
FBF1h AMSSIO Serial Interface MC6850 Data Register (R/W)
Input CLK varies from version to version (v1,v2,v3), in some versions,
the input CLK is jumper-selectable
IRQ pin is not connected (can be read only by software, in Status.Bit7)
Used by [[Music Machine]] (in this case, as MIDI interface, not as RS232 interface): Port addresses and other details on AMSSIO are unknownF8ECh Music Machine ACIA Control (W) F8EDh Music Machine ACIA Data write (W) F8EEh Music Machine ACIA Status (R) F8EFh Music Machine ACIA Data read (R)
== Registers ==
Rx has a 1-stage fifo, plus 1 shift register (2 stages in total)
Tx has a 1-stage fifo, plus 1 shift register (2 stages in total)
== Datasheet ==
* [[Media:MC6850.pdf|Motorola MC6850 datasheet]]
[[Category:Electronic Component]]
