CP/M/CPM_CDROM.iso/cpm/bstam/upmmi2.asm

Assembly Source File | 1994-07-13 | 5KB | 173 lines

;
;    UPMMI.ASM ver 2.0 as of 4/27/80
;       by Keith Petersen, W8SDZ
;
;This is the user area for BSTAM version 4.3 for use with
;a PMMI MM-103 modem.
;
;    IF YOU WISH TO USE OTHER REGISTERS SUCH AS HL,BC,DE
;    (NOT INCLUDING  SP  REGISTER)
;    BE SURE TO PUSH BSTAM'S REGISTERS ON TO STACK AND POP
;    THEM BACK OFF BEFORE RETURNING TO BSTAM.
;    THERE IS AMPLE ROOM TO PUSH ALL REGISTERS ONTO BSTAM'S
;    STACK, PLUS ROOM FOR 10 LEVELS OF CALL'S.
;
;    THERE ARE 300 BYTES OF USER SPACE AVAILABLE TO YOU.
;
;    THE JUMP'S CODED AT THE BEGINNING OF THIS PROGRAM
;    CANNOT BE MOVED IN ANY WAY.
;
;    DEFINE PORTS
;
PMCTL1    EQU    0C0H    ;PMMI UART STATUS PORT
PMDATA    EQU    PMCTL1+1 ;PMMI UART DATA PORT
PMMDMS    EQU    PMCTL1+2 ;PMMI MODEM CHIP STATUS PORT
PMCTL2    EQU    PMCTL1+3 ;PMMI MODEM CHIP CONTROL PORT
;
;    CONDITIONAL ASSEMBLY SWITCH
;
FASTCLK    EQU    0    ;0 = 2 MHZ, 1 = 4 MHZ SYSTEM CLOCK
;
;    DEFINE ASCII CHARACTERS USED
;
CR    EQU    0DH    ;CARRIAGE RETURN
LF    EQU    0AH    ;LINE FEED
;
BEGIN:    ORG    103H
;
INITIL    JMP    INITIU    ;UART/USART INITIALIZATION ENTRY POINT
INSPORT    JMP    INSPRU    ;STATUS PORT READ ENTRY POINT
ERRSET    JMP    ERRSTU    ;UART/USART ERROR RESET ENTRY POINT
INPORT    JMP    INPRTU    ;READ DATA PORT ENTRY POINT
OUTPORT    JMP    OUTPRU    ;WRITE DATA PORT ENTRY POINT
;
;
;    THIS IS THE UART/USART INITIALIZATION ROUTINE.
;    TO BE COMPATIBLE WITH MOST BSTAM USERS USE FOLLOWING
;    INITIALIZATION GUIDE LINES:
;    1. USE 1 STOP BIT    (OPTIONAL - 2)
;    2. USE 8 DATA BITS    (MUST)
;    3. USE 1 START BIT    (MUST)
;    4. USE 16X FOR CLOCK RATE     (MUST)
;    5. USE ASYNCHRONOUS MODE ONLY    (MUST)
;
;
INITIU:    CALL    SIGNON    ;TELL USER WHAT'S IMPLEMENTED
    RET        ;RETURN TO BSTAM
;
;
;    THIS IS THE STATUS READ PORT ROUTINE.
;    WHEN EXITING THIS ROUTINE BSTAM EXPECTS IN REGISTER A
;    THE FOLLOWING BITS TO BE SET IF NEEDED:
;    1. 20 BIT SET IF FRAMING ERROR
;    2. 10 BIT SET IF OVERRUN ERROR
;    3. 08 BIT SET IF PARITY  ERROR
;    4. 04 BIT SET IF TRANSMITTER EMPTY (TEOC)
;    5. 02 BIT SET IF RECEIVER READY (DAV)
;    6. 01 BIT SET IF TRANSMITTER READY (TBMT)
;    7. DO NOT SET THE 80 BIT OR 40 BIT
;
;    BEFORE WE DO THE UART STATUS CHECK WE WILL CHECK TO
;    SEE IF CARRIER IS LOST.
;
INSPRU:    PUSH    B    ;SAVE REGISTERS USED
    PUSH    D
;
    IF    NOT FASTCLK ;FOR 2MHZ SYSTEM CLOCK
    MVI    B,15    ;WAIT UP TO 15 SECONDS
    ENDIF
;
    IF    FASTCLK    ;FOR 4MHZ SYSTEM CLOCK
    MVI    B,30    ;WAIT UP TO 15 SECONDS
    ENDIF
;
;    1 SECOND TIME DELAY ROUTINE. ENTER WITH DESIRED NUMBER OF
;    SECONDS IN B REGISTER.
;
ONESEC:    LXI    D,50000 ;VALUE FOR 2 MHZ CLOCK
;
TLOOP:    IN    PMMDMS    ;GET MODEM CHIP STATUS
    ANI    04H    ;GET CTS (CARRIER DETECT) BIT
    JZ    CARROK    ;CARRIER NOT LOST, EXIT AND RETURN
    DCR    E    ;DECREMENT TIME DELAY VALUE
    JNZ    TLOOP    ;NOT DONE, DO ANOTHER LOOP
    DCR    D    ;DECREMENT TIME DELAY VALUE
    JNZ    TLOOP    ;NOT DONE, DO ANOTHER LOOP
    DCR    B    ;DECREMENT NUMBER OF SECONDS
    JNZ    ONESEC    ;NOT DONE, DO ANOTHER ONE SEC DELAY
;
;    IF WE GET TO HERE, WE HAVE LOST CARRIER FOR 15 SECONDS
;
    POP    D    ;RESTORE REGS
    POP    B
    XRA    A
    OUT    PMCTL1    ;CAUSE MODEM TO...
    OUT    PMCTL2    ;...HANG UP
    LXI    D,LSTMSG ;POINT TO MESSAGE
    MVI    C,9
    CALL    5    ;PRINT IT
    JMP    0    ;EXIT TO CP/M WARM BOOT
;
LSTMSG:    DB    CR,LF,'    ++CARRIER LOST++'
    DB    CR,LF,'The modem is now DISCONNECTED'
    DB    CR,LF,'$'
;
;    CARRIER IS NOT LOST
;
CARROK:    POP    D    ;RESTORE DE REGS
    POP    B
;
;    NOW GET UART STATUS FOR BSTAM.
;    IN THIS CASE WE DISCARD ALL ERROR TEST BITS BECAUSE
;    THE PMMI MODEM HAS NO WAY TO RESET THE ERROR FLAGS
;    ONCE THEY ARE UP, CAUSING A CONTINUOUS DISPLAY OF
;    ERROR MESSAGES IN BSTAM.
;
    IN    PMCTL1    ;GET PMMI UART STATUS
    ANI    07H    ;STRIP ALL BUT TEOC, DAV AND TBMT BITS
    RET
;
;    THIS IS THE ERROR RESET FOR UART/USART ROUTINE.
;    THE PMMI MODEM HAS NO WAY TO RESET THE ERROR FLAGS,
;    SO WE JUST DO A RETURN.
;
ERRSTU:    RET        ;RETURN TO BSTAM
;
;
;    THIS IS THE READ DATA PORT ROUTINE.
;    BEFORE THIS ROUTINE IS ENTERED THE 02 BIT OF
;    STATUS READ ROUTINE MUST HAVE BEEN SET.
;    DO NOT CLEAR THE 80 BIT FROM THE DATA INPUT PORT.
;    RETURN WITH REGISTER A LOADED WITH INPUT DATA.
;
INPRTU:    IN    PMDATA    ;GET DATA FROM PORT
    RET        ;RETURN TO BSTAM
;
;
;    THIS IS THE WRITE DATA PORT ROUTINE.
;    BEFORE THIS ROUTINE IS ENTERED THE 04 BIT AND 01 BIT
;    OF STATUS READ MUST BE SET.
;    DO NOT CLEAR THE 80 BIT FROM THE DATA OUTPUT PORT.
;    REGISTER A CONTAINS THE OUTPUT DATA.
;
OUTPRU:    OUT    PMDATA    ;SEND DATA TO REMOTE CPU
    RET        ;RETURN TO BSTAM
;
SIGNON:    PUSH    B
    PUSH    D
    PUSH    H
    LXI    D,MESSGE
    MVI    C,9
    CALL    5        ;ANNOUNCE VERSION TO USER
    POP    H
    POP    D
    POP    B
    RET
;
MESSGE:    DB    CR,LF,CR,LF
    DB    'PMMI Modem ver 2.0 - no initialization done,'
    DB    CR,LF,'tests for loss of carrier.'
    DB    CR,LF,'$'
;
    END    BEGIN