COMM6 Preliminary man page


NAME
COMM6 - communication program 6

SYNOPSIS
Reads data at 38400 baud from the serial port, saves it in memory starting at address $4000. Ends by timing out after ten seconds with no more data.

DESCRIPTION
Loads into addresses $3000 through $30DF inclusive, starts execution at address $3000.

Reads data from the serial port at 38400 baud, with no parity, eight bits per byte, and one stop bit. Times out after four minutes with no data. Once any data is received, the timeout period is reduced to ten seconds. (So the end of transmission is indicated by simply not sending anything for 10 seconds).

Received data is stored in memory starting at address $4000. Before beginning, the SAM is configured to use 64K of RAM, and the BASIC ROMs are mapped out. So up to 47K of data can be received. Receiving more than 47K would mean writing over the SAM's configuration registers, losing the data that was written, and probably causing the machine to crash. The bytes at addresses $3100 and $3101 contain the address of the next byte that would have been saved; ie: the last address plus one.

Only one sample is taken for each bit. Because of this, it could be less reliable than COMM4 if the input signal is noisey. But no reliability problems have yet shown up in testing.

BUGS


yakowenk@cs.unc.edu, 29-Sep-1999