BEST 1200 - ISA bus internal modem

- Follows standards BELL 103/212A, CCITT V.21/V.22
  (i.e. it can operate in both USA and Europe)

       .-------------------------..--
speaker|         .tr-.       10+-|'
   --> | #BEST#  `ans'         | |  10x DIP-switch
       |                      1+-|.
       | #BEST## #F8T4HL#        ||
       |                       |==  PHONE 4x modular RJ11
       |         ########        ||
       |                       |==  LINE 4x modular RJ11 
       |                         ||
       `------mmmmmmmmmmmmmmmmm--'|
              """""""""""""""""   |

DIP-switch:  (on=down)

No   Default   Function
 1   down      DTR signal always provided by modem
 2   up        Send result code as English word
 3   down      Send result codes
 4   up        Echoes all characters in command mode
 5   down      Do not answer incoming calls
 6   down      CD signal always provided by modem
 7   up        Modem connected to an RJ11 phone jack
 8   down      Make/break pulse-dial ratio. down=USA/Canada
 9   up        Compatible with Bell 103/212A modems.
10   down      COM1

2,3,4,5,8,9 can be overridden by software commands.


Registers:

ATSr? - Read the value in a register
ATSr=n - Set a register value to n

S0. Answer incoming calls.
S1. Increases with each incoming ring. Cleared after 8 seconds.
S2. Escape character (+++). Default 43.
S3. CarriageReturn character. Default 13.
S4. LineFeed character. Default 10.
S5. Backspace character. Default 8.
S6. Wait for dial tone. Default 2 seconds.
S7. Wait for carrier. Default 30 seconds.
S8. Time period of ",". Default 2 seconds.
S9. Minimum carrier signal from remote modem. Default 6 seconds/10.
S10. Maximum loss of signal without disconnect. Default 7 seconds/10.
S11. Time between tones during tone-dialing. Default 70 seconds/1000.
S12. Time before and after escape character (+). Default 50 seconds/50.
S13. Bit:  0/1             Function 
       0   --              undefined
       1   Basic/Extended  result code set
       2   Disable/Enable  parity
       3   Odd/Even        parity
       4   7/8             data bits
       5   --              undefined
       6   no/yes          command buffer overflow
       7   space/mark      8th data bit
S14.   0   Disable/Enable  auto answer (swicht 5)
       1   Disable/Enable  local echo
       2   Enable/Disable  responses
       3   digit/word      result code
       4   on/off          modem recognizes commands
       5   0/1             Make/Break pule dial ratio. 0=67/33%, 1=60/40%
       6   CCITT/BELL      mode
       7   Disable/Enable  long space disconnect
S15.   0   --              same as bit 4
       1   --              same as bit 5
       2   Answer/Original mode
       3   Half/Full       duplex
     4,5   Baud rate       00=undefined, 01=110, 10=300, 11=1200
       6   0/1             0=Connect flag, 1=Disconnect flag
       7   --              undefined
S16. Test mode. 0=Default=datamode. 1=selftest. 2=Continious dial tone.


/ Tomas Andersson 1993-07-19