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/ CP/M / CPM_CDROM.iso / cpm / utils / asmutl / asmlib.lbr / SBCMON.AZM / SBCMON.ASM

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Assembly Source File | 1991-06-25 | 12.3 KB | 544 lines

;---------------------------------------------------------------- ; This program reads 4 digital input lines on an SBC-800 board ; parallel port lines and uses them to count external events. ; It is assumed that the lines will be low, going high, then low ; again. The leading edge is detected and when the falling edge is ; found then a counter is incermented. ; ; Written R.C.H. 23/10/83 ; Last Update R.C.H. 08/12/83 ;---------------------------------------------------------------- ; extrn prolog,inline,cie,coe,cst,cursor,clkrd,bell extrn bell,setxy,pmenu,quit,clear,caps,crlf extrn nolzb,lzb,blzb,phacc,pdde,phde,dispatch,hexbcd extrn curon,curoff,clkrd,xyinline ; data equ 080h ; data port to read for the 4 switches stat equ data+3 ; status port for the data port cntmax equ 030 ; loops between time check & print timx equ 22 ; time x column screen address timy equ 22 ; time y row address ; call prolog call clear lxi d,display ; display a message call pmenu call curoff ; disable the cursor call blzb ; nice blanking is required ; Clear all the counts next call clear0 call clear1 call clear2 call clear3 ; all set to 00, status also ; Now we set up a default status of the on / off switches by setting them on mvi c,0ffh ; all switches on call check4 call check5 call check6 call check7 ; ; Set up the 8255 to be an input device on channel A mvi a,090h ; a inputs, b&c outputs out stat ; mvi a,1 ; display time soonest possible sta counts ; save a loop counter ; ; Now go straight into the loop. ; Read the input port PA0 and detect which switches are on and off ; Use this to detect switch transitions. ; loop: in data mov c,a ; save the data byte call check0 ; bits 0--7 are counters call check1 call check2 call check3 call check4 ; bits 4--7 are on / off switches call check5 call check6 call check7 call chk$counts ; check the loop counter call do$bell ; ring bell only if a changed counter call cst ; character typed ? jz loop call cie call caps cpi 'Q' jz finish lxi h,loop push h ; put a return address on stack cpi '0' jz clear0 cpi '1' jz clear1 cpi '2' jz clear2 cpi '3' jz clear3 cpi 'T' jz tog$bell ; toggle the bell jmp bell ; all else was an illegal character ; finish: lxi d,21 ; line 22 call cursor call crlf call curon ; restore the cursor jmp quit ; ;---------------------------------------------------------------- ; This routine must get the count of the number of times the ; program has looped and when it is 00 it prints the time ; on the screen where it is set up for. ;---------------------------------------------------------------- ; chk$counts: lda counts dcr a sta counts ora a rnz ; exit if not end of loop ; mvi a,cntmax ; get maximum count value sta counts ; Now get the time lxi d,tbuff ; point to time buffer call clkrd ; read the clock into it ; Now check the validity of the time ; Now we check if the seconds has changed since the last time we were here lda old$secs mov c,a ; save lda secs ; get current seconds value cmp c ; same ?? rz ; return now if the same sta old$secs ; save the seconds ; ; Since time is ok, print it after x,y addressing prnt$time: mvi d,timx + 7 mvi e,timy call cursor ; do the set up ; call nolzb lda hrs call phacc ; display it mvi a,':' call dispatch lda mins call phacc mvi a,':' call dispatch lda secs call phacc call blzb ; back to blank filled lzb again ; ; Now print the loops counter. This = the number of seconds we have run. lhld loops inx h shld loops xchg ; load into DE call inline db ' $' call pdde ret ; ;---------------------------------------------------------------- ; The following four routines use the byte passed in and use ; it to detect a switch transition. A switch transition occurrs ; when an input goes high then low. ;---------------------------------------------------------------- ; check0: mov a,c ; fetch input byte ani 1 ; make it a 1 or a 0 only mov e,a ; put into e lda status0 cmp e ; is the previous value the same ?? rz ; exit if so ; We have gone high-> low or low-> high if here jnc c0fall ; no carry means a falling edge ; Here and there is a rising edge. mvi a,1 sta status0 ; save it ret ; Here and a falling edge detected. c0fall: xra a sta status0 lhld s0 ; load the count value inx h shld s0 ; set up cursor and display dsp0: ; The entry to display hl on the screen lxi d,0a06h call cursor xchg call pdde mvi a,0ffh sta ring ; flag a change in a counter ret ; ; Second counter exactly the same way ; check1: mov a,c ; fetch input byte ani 2 ; make it a 1 or a 0 only mov e,a ; put into e lda status1 cmp e ; is the previous value the same ?? rz ; exit if so ; We have gone high-> low or low-> high if here jnc c1fall ; no carry means a falling edge ; Here and there is a rising edge. mvi a,2 ; save the bit number sta status1 ; save it ret ; Here and a falling edge detected. c1fall: xra a sta status1 lhld s1 ; load the count value inx h shld s1 ; set up cursor and display dsp1: ; The entry to display hl on the screen lxi d,0a08h call cursor xchg call pdde mvi a,0ffh sta ring ret ; ; Third counter ; check2: mov a,c ; fetch input byte ani 4 ; make it a 1 or a 0 only mov e,a ; put into e lda status2 cmp e ; is the previous value the same ?? rz ; exit if so ; We have gone high-> low or low-> high if here jnc c2fall ; no carry means a falling edge ; Here and there is a rising edge. mvi a,4 sta status2 ; save it ret ; Here and a falling edge detected. c2fall: xra a sta status2 lhld s2 ; load the count value inx h shld s2 ; set up cursor and display dsp2: ; The entry to display hl on the screen lxi d,0a0ah call cursor xchg call pdde mvi a,0ffh sta ring ret ; ; Fourth and last counter ; check3: mov a,c ; fetch input byte ani 8 ; make it a 1 or a 0 only mov e,a ; put into e lda status3 cmp e ; is the previous value the same ?? rz ; exit if so ; We have gone high-> low or low-> high if here jnc c3fall ; no carry means a falling edge ; Here and there is a rising edge. mvi a,8 sta status3 ; save it ret ; Here and a falling edge detected. c3fall: xra a sta status3 lhld s3 ; load the count value inx h shld s3 ; set up cursor and display dsp3: ; The entry to display hl on the screen lxi d,0a0ch call cursor xchg call pdde mvi a,0ffh sta ring ret ; ;---------------------------------------------------------------- ; These routines display the status of the on / off switches ; connected to bits 4 to 7 inclusive. ; The only time the switch has its message changed is when there is a ; transition from one state to another. All else causes a return. ; On entry register C = the input byte. Each routine checks its bit ; to see if there is a change from the bit saved in memory. If a ; difference then the message is changed and the bit saved. ;---------------------------------------------------------------- ; check4: mov a,c ; fetch the bit ani 010h ; test bit 4 mov e,a ; save it back lda s4 cmp e ; is the original equal to the new ? rz ; This is the immediate exit if no change ; ; Here we do a conditional bell. ; Now write the new bit back to memory then test is the message should be ; an on or off message, print it then return. mov a,e ; restore masked / tested bit sta s4 ora a jz c4off ; display check 4 off message ; Here display the on message lxi d,0c0eh call cursor call inline db ' ON$' ret c4off: lxi d,0c0eh call cursor call inline db 'OFF$' ret ; ; Check the second switch status ; check5: mov a,c ; fetch the bit ani 020h ; test bit 5 mov e,a ; save it back lda s5 cmp e ; is the original equal to the new ? rz ; This is the immediate exit if no change ; ; Here we do a conditional bell. ; Now write the new bit back to memory then test is the message should be ; an on or off message, print it then return. mov a,e ; restore masked / tested bit sta s5 ora a jz c5off ; display check 4 off message ; Here display the on message lxi d,0c10h call cursor call inline db ' ON$' ret c5off: lxi d,0c10h call cursor call inline db 'OFF$' ret ; ; Check the tried switch ; check6: mov a,c ; fetch the bit ani 040h ; test bit 6 mov e,a ; save it back lda s6 cmp e ; is the original equal to the new ? rz ; This is the immediate exit if no change ; ; Here we do a conditional bell. ; Now write the new bit back to memory then test is the message should be ; an on or off message, print it then return. mov a,e ; restore masked / tested bit sta s6 ora a jz c6off ; display check 4 off message ; Here display the on message lxi d,0c12h call cursor call inline db ' ON$' ret c6off: lxi d,0c12h call cursor call inline db 'OFF$' ret ; ; Check the last (bottom) switch ; check7: mov a,c ; fetch the bit ani 080h ; test bit 4 mov e,a ; save it back lda s7 cmp e ; is the original equal to the new ? rz ; This is the immediate exit if no change ; ; Here we do a conditional bell. ; Now write the new bit back to memory then test is the message should be ; an on or off message, print it then return. mov a,e ; restore masked / tested bit sta s7 ora a jz c7off ; display check 4 off message ; Here display the on message lxi d,0c14h call cursor call inline db ' ON$' ret c7off: lxi d,0c14h call cursor call inline db 'OFF$' ret ; ; Clear the counters. This is called at program start and when ; keystroke options are entered ; clear0: xra a lxi h,0 shld s0 sta status0 jmp dsp0 ; display this new value ; clear1: xra a lxi h,0 shld s1 sta status1 jmp dsp1 ; clear2: xra a lxi h,0 shld s2 sta status2 jmp dsp2 ; clear3: xra a lxi h,0 shld s3 sta status3 jmp dsp3 ; ; This is the conditional bell ringer. If the bell status flag is ; 00 then the bell is not sounded else if non zero then it is rung. ; do$bell: lda bell$stat ora a rz ; Now we check the bell code in ring. If this is not 00 then we clear it ; then ring the bell. This byte really only is used to indicate ; a changed counter. lda ring ora a rz ; exit since no counters tripped xra a sta ring ; clear the byte if it is set jmp bell ; return after ringing the bell ; ; This simple routine toggles the bell in and out. The bell is ; in when the bell stat byte is not 00. ; tog$bell: lxi d,0340ah ; col 53, lin 10 call cursor ; lda bell$stat xri 0ffh ; toggle it sta bell$stat ; ora a ; 00 and bell off jz tog$bell2 ; here and the bell is on, next time we toggle off call inline db 'OFF$' ret ; here and the bell is disabled so we toggle it on next time tog$bell2: call inline db 'ON $' ret ; ; Message display area next ; display: db 12,00,'SBC-800 Switch Transition Counter V1.0$' db 00,06,' Count 0$' db 00,08,' Count 1$' db 00,10,' Count 2$' db 00,12,' Count 3$' db 00,14,'Switch 0 $' db 00,16,'Switch 1 $' db 00,18,'Switch 2 $' db 00,20,'Switch 3 $' db 36,04,'------Options----$' db 36,06,'0 = Clear Count 0$' db 36,07,'1 = Clear Count 1$' db 36,08,'2 = Clear Count 2$' db 36,09,'3 = Clear Count 3$' db 36,10,'T = Toggle bell ON$' db 36,12,'Q = Quit$' db timx,timy,'Time$' db timx+24,timy,'Total Seconds$' db 0ffh ; dseg ; ; The next 8 sections are used to detect leading edges and to ; count switch transitions. ; s0 db 00,00 status0 db 00 s1 db 00,00 status1 db 00 s2 db 00,00 status2 db 00 s3 db 00,00 status3 db 00 ; ; The next 4 locations are for the switches ; s4 db 00 s5 db 00 s6 db 00 s7 db 00 ; ; Status flags ; bell$stat: db 00 ; 00 = bell off, else bell on ring db 00 ; 00 = no ring, 0ffh = change so ring ; ; A buffer to read the time into ; loops db 00,00 ; loop counter = total seconds run counts db 00 ; count program loops old$secs db 00 ; Save to check time against ; tbuff: db 00,00,00,00 ; year, month, day, dow hrs db 00 mins db 00 secs db 00 ; end