; ; TITLE ZMDP-1.Z80 - 01/01/88 - ZMD I/O Overlay for DATAPOINT 1560 ; Copyrighted (c) 1987, 1988 ; Robert W. Kramer III PAGE ;- -; ; Update History ; ; ; ; Date Release Comments ; ; -------- ------- ---------------------------------------------- ; ; ; ; 01/01/88 v1.00 - Initial version ; ;- -; ; MODCTLP EQU 029H ; First control/status port MODDATP EQU MODCTLP-1 ; Data in port MODSNDB EQU 1 ; Bit to test for send MODSNDR EQU 1 ; Value when ready MODRCVB EQU 2 ; Bit to test for receive MODRCVR EQU 2 ; Value when ready MODDCDB EQU 4 ; Carrier detect bit MODDCDA EQU 0 ; Value when active ; ;-------------------------------------------------------------------------; ; Input/Output Jump Table | ;-------------------------------------------------------------------------; ; ORG 580H ; Start after configuration table JP 00000H ; See CONOUT.INF JP INIT ; Initialization routine (if needed) JP UNINIT ; Undo whatever 'MINIT' did (or return) JP SNDCHR ; Send character (via POP PSW) 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 ; Get the character back OUT (MODDATP),A ; Send it to the modem output RET ; ;-------------------------------------------------------------------------; ; Check for carrier | ;-------------------------------------------------------------------------; CARCHK: XOR A RET ; ;-------------------------------------------------------------------------; ; Get character from modem | ;-------------------------------------------------------------------------; GETCHR: IN A,(MODDATP) ; Get character from data in port RET ; ;-------------------------------------------------------------------------; ; Check modem receive ready | ;-------------------------------------------------------------------------; RCVRDY: IN A,(MODCTLP) ; Get modem status AND MODRCVB ; Isolate ready bit CP MODRCVR ; Test it RET ; Z = character available ; ;-------------------------------------------------------------------------; ; Check modem send ready | ;-------------------------------------------------------------------------; SNDRDY: IN A,(MODCTLP) ; Get status byte AND MODSNDB ; Isolate ready bit CP MODSNDR ; Ready to send? RET ; ; END