; TITLE ZMZB-1.Z80 - 01/01/88 - ZMD I/O Overlay for ZORBA BIOS/HAYES ; Copyrighted (c) 1987, 1988 ; Robert W. Kramer III PAGE ;- -; ; Update History ; ; ; ; Date Release Comments ; ; -------- ------- ---------------------------------------------- ; ; ; ; 01/01/88 v1.00 - Initial version ; ;- -; ; MSPORT EQU 21H ; Status register for rs232 TXRDY EQU 1 ; Bit to test for ready to send RXRDY EQU 2 ; Bit to test for received data DPORT EQU 20H ; Data port ; ;-------------------------------------------------------------------------; ; Input/Output Jump Table | ;-------------------------------------------------------------------------; ; ORG 0580H ; Start after configuration table JP 0000H ; See CONOUT.INF JP INIT ; Initialization routine JP UNINIT ; Unititialize routine JP SNDCHR ; Send character JP CARCHK ; Test for carrier JP GETCHR ; Get character from modem JP RCVRDY ; Check receive ready JP SNDRDY ; Check send ready ; ;-------------------------------------------------------------------------; ; System startup inititialization routine | ;-------------------------------------------------------------------------; INIT: RET ; ;-------------------------------------------------------------------------; ; System exit unititialization routine | ;-------------------------------------------------------------------------; UNINIT: RET ; ;-------------------------------------------------------------------------; ; Send character out modem | ;-------------------------------------------------------------------------; SNDCHR: POP AF ; Load up the character from the stack OUT (DPORT),A ; Send char RET ; ;-------------------------------------------------------------------------; ; Check for carrier | ;-------------------------------------------------------------------------; CARCHK: IN A,(MSPORT) AND 80H ; Mask DSR XOR 80H RET ; ;-------------------------------------------------------------------------; ; Get character from modem | ;-------------------------------------------------------------------------; GETCHR: IN A,(DPORT) ; Get character from data port RET ; ;-------------------------------------------------------------------------; ; Check modem receive ready | ;-------------------------------------------------------------------------; RCVRDY: IN A,(MSPORT) ; Get status AND RXRDY ; Mask SUB RXRDY ; Z = ready RET ; Done ; ;-------------------------------------------------------------------------; ; Check modem send ready | ;-------------------------------------------------------------------------; SNDRDY: IN A,(MSPORT) ; Get status AND TXRDY ; Mask SUB TXRDY ; Z = ready RET ; Done END