ftp.barnyard.co.uk/2015.02.ftp.barnyard.co.uk.tar/ftp.barnyard.co.uk/cpm/walnut-creek-CDROM/CPM/BBSING/MBBS/MBC-KPRO.ASM

Assembly Source File | 2000-06-30 | 5KB | 204 lines

;
;**********************************************************************
;
; MBC-KPRO.ASM -- Version 1.0 -- 03/01/84 -- by Kim Levitt
;
;    CLOCK routine for MBYE running on Kaypro 2 with Pro-Clock
;    (adapted from Kaypro Pro-Clock driver written by Greg Haerr)
;
;    This overlay is designed to work on a Kaypro II running MBYE
;    and equipped with a Business Computer Systems Pro-Clock RTC.
;    (Use the DATE program to initialize the clock outside of BYE.)
;    (BCS address: 5350 South 3600 West; Salt Lake City, UT 84118)
;
;    When called this routine will check the RTCBUF. If a '99H'
;    is in the first byte, the clock is initialized. Next the
;    seconds are checked, and if changed since last update of
;    RTC buffer, the clock is stopped, data copied to RTCBUF and
;    the clock is restarted. (If no change in seconds, the
;    routine returns immediately.)
;
;**********************************************************************
;
CLOCK:
    PUSH    PSW        ; save ALL regs that are used
    PUSH    B
    PUSH    H
    LDA    RTCBUF        ; get first BCD byte
    CPI    099H        ; 99 ?
    CZ    CLKINIT        ; if so, init clock...
    CALL    HOLDON        ; put clock on hold
    MVI    C,0        ; check low seconds
    CALL    RDPIO        ; to see if change...
    LXI    H,RTCBUF+2    ; compared to old secs
    XRA    M        ; value stored in
    ANI    0FH        ; RTC buffer (low nibble)
    JZ    CLKEXIT        ; if no change, skip update
    MVI    C,5        ; start with hi hours
    LXI    H,RTCBUF    ; and copy to RTCBUF
    CALL    GETCLK        ; (get time)
    MVI    C,12        ; start with hi year
    LXI    H,RTCBUF+4    ; and copy to RTCBUF
    CALL    GETCLK        ; (and date)
    LDA    RTCBUF        ; get hours
    ANI    03FH        ; mask out PM/24 hour bits
    STA    RTCBUF
    LDA    RTCBUF+6    ; get day
    ANI    03FH        ; mask out leap year bit
     STA    RTCBUF+6
CLKEXIT:
    MVI    C,13        ; set clock addr. to
    CALL    WRADDR        ; junk location so no data cleared
    CALL    HOLDOFF        ; when we take clock off hold..
    POP    H        ; restore ALL regs
    POP    B
    POP    PSW
    RET            ; and return (for now..)
;
GETCLK:
    MVI    B,3        ; repeat 3 times for 3 BCD bytes
CLKLP:
    CALL    RDPIO        ; get data at address C
    RLC ! RLC ! RLC ! RLC    ; move to high nibble for BCD
    MOV    M,A        ; save at location temporarily
    DCR    C        ; decrement clock addr
    CALL    RDPIO        ; get data at next address
    ORA    M        ; OR with previously saved data
    MOV    M,A        ; and save it
    DCR    C        ; decrement clock addr
    INX    H        ; increment to next BCD byte
    DCR    B        ; decrement BCD counter
    JNZ    CLKLP        ; if 3rd BCD byte, done..
    RET            ; return
;
; PIO STUFF
;
MODE3    EQU    0CFH    ; bit control mode
;
DATA    EQU    0AH    ; port B data
CMD    EQU    0BH    ; port B cmd
;
; mask values for clock chip
;
LATCH    EQU    80H    ; set address latch (active high)
WR    EQU    40H    ; write (active high)
RD    EQU    20H    ; read (active high)
HOLD    EQU    10H    ; time hold (active high)
;
CLKINIT:
    MVI    A,7        ; disable interrupts
    OUT    CMD
;
; fall into set output
;
; set output mode
;
SETOUT:
    LDA    FLAG        ; get current state
    OUT    DATA        ; preset data register
    MVI    A,MODE3        ; set bit control mode
    OUT    CMD
    XRA    A        ; set all outputs mask
    OUT    CMD
    LDA    FLAG
    OUT    DATA
    RET
;
; set input mode
;
SETIN:
    LDA    FLAG        ; get current state
    ORI    RD        ; set read line
    OUT    DATA
    MVI    A,MODE3
    OUT    CMD
    MVI    A,0FH        ; d7-d4 are still output, mask em'
    OUT    CMD
    LDA    FLAG
    ORI    RD
    OUT    DATA
    XCHG ! XCHG        ; delay for 6 uS min.
    RET
;
; send data in A to address in C
;
WRPIO:
    MOV    B,A        ; save data in B
    CALL    WRADDR        ; set address
    MOV    A,B        ; fall into write data
;
; write data in A
;
WRDATA:
    MOV    C,A        ; save in C
    LDA    FLAG        ; get current flag
    ORA    C        ; or in data
    OUT    DATA
    ORI    WR        ; and write it
    OUT    DATA
    NOP            ; delay for 1 uS min
    NOP
    ANI    (NOT WR) AND 0FFH    ; reset write
    OUT    DATA
    RET
;
; read data into A from address in C
;
RDPIO:
    PUSH    B
    CALL    WRADDR        ; set address
;
; fall into read data
;
; read data into A
;
RDDATA:
    CALL    SETIN        ; set input mode
    IN    DATA        ; input data
    ANI    0FH        ; just in case
    MOV    C,A        ; save in C
    CALL    SETOUT        ; set to output mode
    MOV    A,C        ; get saved data
    POP    B        ; restore BC
    RET
;
; latch address in C
;
WRADDR:
    LDA    FLAG        ; get current flag
    ORA    C        ; or in address
    OUT    DATA        ; send address
    ORI    LATCH        ; set latch
    OUT    DATA        ; and latch it
    ANI    (NOT LATCH) AND 0FFH
    OUT    DATA
    RET
;
HOLDON:
    MVI    A,HOLD        ; set hold flag
    STA    FLAG
    CALL    WRDATA
HOLD0:
    MVI    B,20        ; wait 150 uS
HOLD1:
    XCHG ! XCHG
    DCR    B
    JNZ    HOLD1
    RET
;
HOLDOFF:
    XRA    A        ; reset hold flag
    STA    FLAG
    JMP    WRDATA
;
FLAG:    DB    0        ; current hold/nohold status flag
;
;**********************************************************************
;
; This is the end of the CLOCK routine overlay for MBYE-31. If you
; include this after your modem overlay, and have a Kaypro 2 equipped
; with a Pro-Clock, it SHOULD work fine...
;
;**********************************************************************
;