serial ports

[fleming@utdallas.edu (Mike Fleming)]

I am trying to use the serial port on an XL1200 to control a Sony tape machine
directly. The tape machine uses 38400 baud, 8 data bits, odd parity, and one
stop bit. When I send a byte to the tape machine, it responds with a NAK, a
byte indicating a parity error, and the correct checksum. The serial stream
is opened with the proper parameters. :Check-parity-errors is t. When I change
the parity on the symbolics side to :even, I get the same response, no parity
error is generated. I've connected the 1200 to a 70. When the parity is
different on the two machines, the 70 generates the error, the 1200 doesn't.
I've tried controlling the tape machine from the 70 with no response. Will a
70 really do 38k bps? Two 70's communicate fine at 38k.
What's going on here?
Michael.