CHAPTER 19 _____ DIARY This section describes the workings of the top level functions DIARY and ALARM. The ORGANISER II manual describes how to use the DIARY and ALARMS. ____________ 19.1 DIARY FORMAT The information in the diary is stored in RAM in an allocated CELL, separate from the RAM device A:, so the diary can not be accessed as a file from OPL or by the top level functions FIND and SAVE. Entries are kept sorted by date and time, and apart from general data on A:, in order to allow alarm checking interrupts to scan the diary efficiently. This also enables the SAVE and RESTORE functions to save the whole diary as a block easily. For information on the storage allocator, see section 6.3.2. The diary is held in the third cell, base pointer $2004. Below the diary are the DEVICE and MENU cells, so any operation which grows or shrinks these cells will cause the diary to move. This includes calls to DV$ and TL$ services, device booting at the top level and any changes in the top level menu. Within the diary cell the entries are stored as follows : BYTE RANGE 0 1 - 64 length of text 1 0 - 99 year 2 0 - 11 month 3 0 - 30 day 4 0 - 23 hour 5 0 or 30 minutes 6 0 - 60 if 0 no alarm set else (number of minutes early+1) 7 text of diary entry ... (1-64 chars) ... ... Example : 12 JAN 1986 17:00 ABCDEF (alarm set 15 minutes early Bytes : $06 length of "ABCDEF" $56 year 1986 $00 month JAN $0B day 12 $11 hour 17 $00 minutes 0 $10 15 minutes early 6 bytes "ABCDEF" next entry or 0 terminator The diary is terminated by a byte zero, not by the end of the cell and so at initialisation time the diary cell just contains this zero byte. It is illegal to shrink the cell to nothing using AL$ZERO or AL$SHNK. The following examples scan through each diary entry : LDX $2004 ; X points to 1st byte BRA 2$ 1$: ADD B,#7 ; skip length byte date alarm flag ABX ; and skip over text 2$: LDA B,0,X ; get length byte BNE 1$ ; until 0 terminator found ADDR% = PEEKW($2004) LEN% = PEEKB(ADDR%) WHILE LEN% <> 0 ADDR% = ADDR% + 7 + LEN% LEN% = PEEKB(ADDR%) ENDWH The diary is saved on the datapacks as a block file of type $82 (see section 12.1.3). Bear in mind the following restrictions when manipulating the diary : 1) Use SEI to prevent alarm checking interrupts while the diary is being modified or during loading from a datapack. Also see below, section 19.3. 2) All entries must be inserted in chronological order 3) No two entries must have the same time 4) The time must be in the year range 1900-1999 with minutes 0 or 30 5) Text must be less than 65 chars 6) The AL$ system services must be used to allocate space in the diary The following OPL program writes a formatted listing of the diary to either a file or the RS232. The main procedure is "DIARY:". OUTLINE:(STRING$) IF CHOICE%=1 A.A$=STRING$ APPEND ELSE LPRINT STRING$ ENDIF DIEND%: RETURN (PEEKB(PTR%)=0) INIT: PTR%=PEEKW($2004) PREVDAY$="" DIG2$:(NUM%) RETURN RIGHT$("0"+NUM$(NUM%,6),2) OUTENTRY: OUTLINE:("") IF LEN(DAY$) OUTLINE:(DAY$) ENDIF OUTLINE:(TIME$) OUTLINE:(DATA$) GETENTRY: LOCAL YEAR%,MONTH%,DAY%,HOUR%,MINUTE%,ALARM%,LEN%,D%,ENDP% LOCAL AMPM$(2) YEAR%=1900+PEEKB(PTR%+1) MONTH%=PEEKB(PTR%+2) DAY%=1+PEEKB(PTR%+3) HOUR%=PEEKB(PTR%+4) MINUTE%=PEEKB(PTR%+5) ALARM%=PEEKB(PTR%+6) DAY$=WKDAY$:(PTR%+1)+" "+NUM$(DAY%,-2)+" "+ MID$("JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC",MONTH%*3+1,3)+ " "+NUM$(YEAR%,4) IF PREVDAY$=DAY$ DAY$="" ELSE PREVDAY$=DAY$ ENDIF AMPM$="AM" IF HOUR%>=12 AMPM$="PM" IF HOUR%>12 HOUR%=HOUR%-12 ENDIF ENDIF TIME$=" "+DIG2$:(HOUR%)+"."+DIG2$:(MINUTE%)+" "+AMPM$ IF ALARM% TIME$=TIME$+" ALARM SET " IF ALARM%>1 TIME$=TIME$+DIG2$:(ALARM%-1)+" MINUTES EARLY." ENDIF ENDIF DATA$=" " LEN%=PEEKB(PTR%) PTR%=PTR%+7 ENDP%=PTR%+LEN% D%=ADDR(DATA$)+LEN(DATA$)+1 DO POKEW D%,PEEKW(PTR%) D%=D%+2 PTR%=PTR%+2 UNTIL PTR%>=ENDP% POKEB ADDR(DATA$),LEN(DATA$)+LEN% PTR%=ENDP% ASKFILE: LOCAL READY%,ERR% LOCAL FILE$(10),K$(1) AGAIN:: ONERR HANDLER:: DO DO CLS PRINT "FILE "; TRAP INPUT FILE$ IF ERR RAISE ERR ENDIF FILE$=UPPER$(FILE$) UNTIL LEN(FILE$) READY%=0 TRAP OPEN FILE$,A,A$ IF ERR AND (ERR<>234) RAISE ERR ENDIF TRAP CLOSE IF EXIST(FILE$) CLS PRINT FILE$;" EXISTS" PRINT "DELETE [Y/N]?"; DO K$=UPPER$(GET$) IF K$=CHR$(1) RAISE 206 ENDIF UNTIL K$="Y" OR K$="N" IF K$="Y" DELETE FILE$ READY%=1 ENDIF ELSE READY%=1 ENDIF UNTIL READY% CREATE FILE$,A,A$ RETURN HANDLER:: ERR%=ERR TRAP CLOSE IF ERR%=206 STOP ELSEIF ERR%=236 OR ERR%=243 CLS PRINT CHR$(16);ERR$(ERR%); IF GET=1 STOP ENDIF GOTO AGAIN:: ENDIF RAISE ERR% WKDAY$:(ADDR%) LOCAL ND%,YR%,M% YR%=PEEKB(ADDR%) M%=PEEKB(ADDR%+1) ND%=YR%+YR%/4+PEEKB(ADDR%+2)+ASC(MID$("035136240250",M%+1,1))+ND%-(((YR% AND 3)=0) AND (M%<=1)) RETURN MID$("SUNMONTUEWEDTHUFRISAT",(ND%-ND%/7*7)*3+1,3) DIARY: GLOBAL CHOICE%,PTR%,DAY$(50),TIME$(50),DATA$(100),PREVDAY$(50) CLS CHOICE%=MENU("FILE,PRINTER") IF CHOICE% INIT: IF DIEND%: PRINT "DIARY EMPTY"; GET ELSE IF CHOICE%=1 ASKFILE: ENDIF DO GETENTRY: OUTENTRY: UNTIL DIEND%: IF CHOICE%=1 CLOSE ENDIF ENDIF ENDIF __________________ 19.2 ALARM TABLE FORMAT The eight alarms are stored in a fixed length 48 byte area AMT_TAB ($22F9). Each entry contains a date-time in the usual format, with a flag indicating the type of alarm. BYTE RANGE 0 0 - 99 year 1 0 - 11 month 2 0 - 30 day 3 0 - 23 hour 4 0 - 59 minutes 5 0 - 4 0 means alarm cancelled 1 non-repeating 2 weekly, 3 daily, 4 hourly repeat An alarm entry is cancelled by setting byte 5 to zero. Before setting or modifying any alarms, byte 5 should be cleared and then set last of all. This is to prevent interrupts from checking that entry. Note that although there is no way of manually setting an alarm outside the current week, this limitation need not apply to user programs which manipulate AMT_TAB directly. You can set an alarm to ring at any time between 1900 and 2000, exclusive of 2000. The date-time of a repeating alarm is updated each time it rings ; an alarm entry does not contain the original date-time. _________________________ 19.3 ALARM CHECKING INTERRUPTS Both the diary and the alarms are scanned approximately every minute by the 50ms maskable interrupts which scan the keyboard. Users wishing to alter the alarm or diary alarm action, see section 7.3 vector BTA_OCI, or section 20.0.1 BZ$ALRM service. Every minute an NMI makes a request for alarm checking by setting the flag AMB_DOIT provided the following conditions are met : BTB_IGNM <> 0 (else NMI does nothing) AMB_EI <> 0 TMB_SECS = 0 (we are on a minute boundary) The flag AMB_EI is provided specifically so that user programs can disable alarm checking. If all these conditions are met, the alarm is not actually checked immediately : this is left to the next maskable interrupt which rings any pending alarms whenever AMB_DOIT is set. This means that alarms are checked as soon as possible after each minute boundary, but any time-critical activities such as writing to datapacks and other operations can delay alarms by using the SEI instruction. Alarms will never occur while the interrupt mask is set. Also certain activities such as device booting (DV$ calls), storage management (AL$ calls), or modification of the diary or alarms can cause an ALARM to ring late. If interrupts are not required, then an SEI instruction is all that is required to disable alarm checking. If interrupts are required the following code must be used to maintain compatibility with all OS versions : LDA A,AMB_EI PSH A TPA ; preserve interrupt mask SEI CLR AMB_EI ; prevent NMI setting AMB_DOIT CLR AMB_DOIT ; in case AMB_DOIT already set TAP ; restore interrupt mask ... ; user program alarm checking now off ; ... ; the next two lines are optional INC AMB_EI ; set AMB_DOIT if check required ** INC AMB_DOIT ; on next interrupt ** PUL A STA A,AMB_EI ; restart normal checking The two lines ** will cause the next 50 ms interrupt to perform a check without waiting for the next minute boundary. This will minimise any late running of the alarms. The AMB_DOIT flag can also be set to request more frequent checking than once each minute. However, AMB_DOIT must at no time be set non-zero when AMB_EI is zero as this may cause problems with some early OS versions. Note also that AMB_EI should not be set to $FF. The 50 ms interrupt first checks the DIARY then the eight alarms. All alarms are sounded even if they are overdue. The earliest DIARY alarm will sound, then the lowest numbered ALARM alarm. If more than one DIARY or ALARM alarm are due, they will ring in pairs (DIARY, ALARM) each minute. Before a DIARY alarm sounds, the alarm flag (byte 6) in that entry is cleared. Before an ALARM alarm sounds, the repeat time is added on for repeating alarms, and byte 5 is cleared for non-repeating alarms. The system service DP$SAVE (see section 8.3.5) is called to save the screen, and the time and diary text or "ALARM" is displayed for one minute or until ON/CLEAR is pressed. The screen is then restored with a call to DP$REST (see section 8.3.6). The ON/CLEAR key is polled directly, so the keyboard buffer is not affected. BZ$ALRM makes the ALARM sound, while the DIARY beep is a call to BZ$TONE with D = 200 (proportional to 1/frequency), X=50 (note length). ______________________ 19.4 WAKING UP FOR AN ALARM The Organiser II maintains the system time with a 12 bit external counter while switched off (see section 2.6). The machine switches on when the counter overflows every 2048 seconds (34 minutes 8 seconds), updates the system time, and switches off again. The system service BT$SWOF rings any alarms pending, then checks if an alarm is due in the next 34 mins 8 secs. If necessary, BT$SWOF sets the counter to a value greater than zero to switch the machine on early. When the Organiser II switches on, it rings the alarm then remains on until normal switch-off. Users wishing to alter this behaviour see section 5.4 for vector BTA_SOF, and section 5.3.2 for vector BTA_WRM.