Bit Banger was Analog modem emulator?
swtpc6800 at comcast.net
Mon Aug 15 20:05:50 CDT 2005
An early example of a bit banger serial interface was the Motorola 6800
MIKBUG Monitor ROM. It used a parallel interface chip (MC6820 PIA) as a
bidirectional serial interface. It would work at 110 and 300 baud (some
people clocked it at 1200 baud.) This was the used in original (1975)
Southwest Technical Products 6800 computer. Motorola had a real UART (MC6850
ACIA) at the time so I don't know why Motorola did this. SWTPC later
switched the their own Monitor ROM and a MC6850 serial port.
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