Epson 500 Series - Manual (Page 96)

Option Register
S14 Bit mapped configuration register
Bit 0 Unused
Bit 1 0 Command echo disabled (E0)
1 Command echo enabled (default E1)
Bit 2 0 Result codes enabled (default Q0)
1 Result codes disabled (Q1)
Bit 3 0 Digit result codes (V0)
1 Word result codes (default V1)
Bit 4 Unused
Bit 5 0 Tone dial (T)
1 Pulse dial (default P)
Bit 6 Unused
Bit 7 0 Answer mode
1 Originate mode (default)
S21 Bit mapped configuration register
Bit 012 Unused
Bit 34 0 0 Modern ignores DTR (&D0)
01 On-to-Off transition on DTR causes the modem to go to the
command state (&D1)
10 On-to-Off transition on DTR cause the modem to hang up
(default &D2)
11 On-to-Off transition on DTR causes the modem to reset (&D3)
Bit 5 0 DCD always ON (&C0)
1 DCD tracts the actual state of the data carrier (default & C1)
Bit 6 Unused
Bit 7 0 Long Space Disconnect disabled (default Y0)
1
Long Space Disconnect enabled (Y1)
B-10 Fax/Modem