FBEFh KDS RS232 6850 (reversed-bit-order) RX Data (R)
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). And, reportedly, the hardware handshaking doesn't work properly (no idea if that's a hardware or software glitch, or maybe the 6850's 1-stage RXFIFO is just too small for high baudrates?).
* [[6850 ACIA chip]]
* [[8253 chip]]
* [[Media:MC6850.pdf|Motorola MC6850 datasheet]]