Comments - Husky MP2500 Manual

Bits of AL indicate the modem handshake status as follows, when set:
Bit Significance
7 Receive line signal detect
6
Ring Indicator (RI) – Not supported by MP2500
5
Data Set Ready (DSR)
4
Clear To Send (CTS)
3
Delta Receive line signal detect
2
Trailing edge RI (Ring Indicator) – Not supported by
MP2500
1
Delta DSR 0 Delta CTS

Comments

IBM PC BIOS provides five functions:
00H Initialise port
01H Send a character
02H Receive a character
03H Get port status
04H Extended initialise port (PS/2-compatible)
MP2500 BIOS provides identical functions, plus a number of extensions,
providing access to additional facilities such as higher speeds and
protocols, listed below. The functions marked with an asterisk (*) are
ignored by MP2500 but ARE supported by FS3 - see Appendix G for more
information.
1EH Read communications parameters
1FH No effect
20H Select communications parameters
21H Extended control
22H Extended status
23H Control handshaking
24H Reserved
25H Reserved
26H Ignored *
27H Get installed protocols count
28H Get protocol name
29H Get protocol handle
2AH Extended protocol menu
218 H MP2500 System Developer's Guide
USKY