UNIDENTIFIED
1200/300 BAUD MODEM
| 
 Modem Type  | 
 Data (synchronous/asynchronous)  | 
| 
 Maximum Data Rate  | 
 1200bps  | 
| 
 Data Bus  | 
 8-bit ISA  | 
| 
 Data Modulation Protocol  | 
 Bell 103 & 212A, ITU-T V.22  | 
| 
 Error Correction/Compression  | 
 Unidentified  | 

| 
 CONNECTIONS  | |||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 Line-in  | 
 J1  | 
 Line-out  | 
 J2  | 
| 
 INTERRUPT SELECT - JP1  | ||||
| 
 í IRQ | 
 Jumper A  | 
 Jumper B  | 
 Jumper C  | 
 Jumper D  | 
| » IRQ4 | 
 Open  | 
 Open  | 
 Closed  | 
 Open  | 
| 
 í IRQ2 | 
 Closed  | 
 Open  | 
 Open  | 
 Open  | 
| 
 í IRQ3 | 
 Open  | 
 Closed  | 
 Open  | 
 Open  | 
| 
 í IRQ5 | 
 Open  | 
 Open  | 
 Open  | 
 Closed  | 
| 
 ADDRESS SELECT  | ||
| 
 í COM/Address | 
 SW1/1  | 
 SW1/2  | 
| » COM1/3F8h | 
 Off  | 
 Off  | 
| 
 í COM2/2F8h | 
 Off  | 
 On  | 
| 
 í COM3/3E8h | 
 On  | 
 Off  | 
| 
 í COM4/2E8h | 
 On  | 
 On  | 
| 
 RECEIVED LINE SIGNAL DETECT BIT (RLSD)  | |
| 
 í Setting | 
 SW1/3  | 
| » RLSD bit reset/carrier detect status written to modem status register. | 
 Off  | 
| 
 í RLSD bit written to modem status register. | 
 On  | 
| 
 DATA TERMINAL READY (DTR)  | |
| 
 í Setting | 
 SW1/4  | 
| » DTR bit status written to the UART modem control register. | 
 Off  | 
| 
 í DTR bit is ignored. | 
 On  | 
| 
 PROTOCOL SELECT  | |
| 
 Protocol  | 
 SW1/5  | 
| » Bell 103 & 212A enabled. | 
 Off  | 
| 
 í CCITT V.22 enabled. | 
 On  | 
| 
 MAKE/BREAK RATIO  | |
| 
 í Setting | 
 SW1/6  | 
| » 39/61 ratio (Bell standard). | 
 Off  | 
| 
 í 33/67 ratio (CCITT standard). | 
 On  |