;-----------------------------------------------------------------
; MXC-KC10.ASM
; clock overlay for mex and the Kenmore Computer Technologies (KCT)
; Ztime-I real-time clock.
rev equ 12 ;V 1.2
; V1.2 30 Aug 86 - Fixed Year storage to chip - Rea Williams
; V1.1 26 Apr 85 - Added CSET routine - Joe Griffith
; V1.0 24 Apr 85 - Original, TM-KCT11.ASM - Joe Griffith
;--------------------------------------------------------------------
; This overlay provides the current date and time to MEX+ or higher
; versions of MEX. It is configured for the Kenmore Computer
; Technologies (KCT) Ztime-I real-time calendar/clock although it
; will probably work with any clock using the MM58167A clock chip.
no equ 0
yes equ 0ffh
i8080 equ yes ;for xlat- do not change
i8086 equ no
cpm equ yes
pcdos equ no
cr equ 13
lf equ 10
mex equ 0D00h ;address of the service processor
ilp equ 240 ;inline print
sblank equ 244 ;scan input stream to next non-blank (cy=end)
evala equ 243 ;evaluate number from input to HL
gnc equ 241 ;get next character
decout equ 239 ;decimal output from HL
bport equ 0E0h ;base port address for KCT clock
;this address should be changed to
;reflect wherever your MM58167A is.
centry equ 1900 ;hard code since it is not available
;from the clock chip
if i8080
db 0c3h ;show which processor we are for
endif
if i8086
db 0E9h
endif
;-----------------------------------------------------------------
; JMP table for clock overlay
org 0e00h ;start of clock overlay
jmp gettim ;get time
jmp getdat ;get date
jmp setclk ;cset processor
ret ;clock overlay init
nop
nop
ret ;clock overlay de-init
thisyr: db 0 ;this is actually the space reserved
;for the address portion of the jmp
;but no de-init is needed so the year
;is stored here. Note that the system
;must be cloned after the clock is set
;to permanently store the year here.
hlpflg: db 0 ;likewise the help flag is stored here
;--------------------------------------------------------------------
; subroutine GETTIM returns the time as follows:
;
; B - Hours (0-23)
; C - Minutes (0-59)
; D - Seconds (0-59)
; E - Hundreths of seconds (0-99)
gettim: in bport+2 ;get seconds
push psw ;save for future reference
call makbin ;make it a binary number
mov d,a ;store it
in bport+3 ;get minutes
call makbin
mov c,a
in bport+4 ;get hours
call makbin
mov b,a
in bport+2
mov l,a ;store it
pop psw ;get original seconds back
cmp l ;compare the two
jnz gettim ;not the same so do it over else
mvi e,0 ;clear hundreds of seconds
ret
;------------------------------------------------------------------------
; subroutine GETDAT returns the date as follows:
;
; BC - Year (1985-2099)
; D - Month (1=January, 2=February, etc.)
; E - Day of month (1-31)
getdat: in bport+2 ;get seconds
push psw ;save it for future reference
in bport+7 ;get month
call makbin
mov d,a
in bport+6 ;get day of month
call makbin
mov e,a
in bport+2 ;get seconds again
mov l,a ;store temporarily
pop psw ;get original seconds
cmp l ;compare the two
jnz getdat ;if not the same do it over
in bport+9 ;get year
call makbin
mov c,a ;put in it's proper place
mvi b,0
lxi h,centry ;load the century
dad b ;add it to the stored value
mov c,l ;move hl to bc
mov b,h
ret
;-----------------------------------------------------------------
; This routine takes the two BCD values in each nibble of the
; accumulator and converts it to a single binary value.
makbin: push d ;save the current value
push psw ;save the original value
rrc ;put the 10s value in the lower bits
rrc
rrc
rrc
ani 0Fh ;mask off whatever is in the high nibble
add a ;multiply this register by 10
mov e,a
add a
add a
add e
mov e,a ;save in e
pop psw ;get the original value
ani 0Fh ;allow only low bits
add e ;get total to a
pop d ;restore de
ret ;all done
;----------------------------------------------------------------------
; CSET processor. This routine allows the user to set the clock from
; command level by typing CSET yy/mm/dd hh:mm:ss.
setclk: call ilprt
db 'KCT Clock OVR V'
db rev/10+'0','.'
db rev mod 10+'0'
db cr,lf,lf,0
xra a ;get a zero
sta hlpflg ;store it as a flag
call twobcd ;get the first two numbers
rc
out bport+9 ;put in the year
call twobcd ;get the month
rc
out bport+7 ;put in the months counter
call twobcd ;get the day of the month
rc
out bport+6 ;put in the day counter
call twobcd ;get the hour
rc
out bport+4 ;put in the hour counter
call twobcd ;get the minutes
rc
out bport+3 ;put in the minutes counter
call twobcd ;get the seconds
rc
out bport+2 ;put in the seconds counter
ret
;------------------------------------------------------------------
; this routine looks at the CSET parameter and returns with a BCD
; pair in the two nibbles of the accumulator. Blanks and separators
; are skiped. The carry flag is set when the end of the line is
; reached.
twobcd: call getnum ;get the 10's digit
jc chlp ;no numbers there
rrc ;put it in the high nibble
rrc
rrc
rrc
push psw ;save it
call getnum ;get the 1's
mov b,a ;temporary storage
pop psw ;get the 10s back
ora b ;merge the two
ret
getnum: mvi c,gnc ;get the next character
call mex
rc ;carry means there is no more input
cpi '0'
jc getnum ;char is smaller than ascii zero
cpi ':'
jnc getnum ;char is not an ascii digit
cmc ;reset carry flag
sta hlpflg
sbi '0' ;make it a binary value
ret
chlp: lda hlpflg ;get the help flag
cpi 0 ;is it null
stc ;flag the end
rnz ;if not then don't print
call ilprt
db 'CSET YY/MM/DD HH:MM:SS'
db cr,lf,lf,0
stc ;flag the system
ret
