Difference between revisions of "OSWORD &0E"
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{{PageTitle|OSWORD &0E (14): Read Real-Time clock}} | {{PageTitle|OSWORD &0E (14): Read Real-Time clock}} | ||
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On entry: | On entry: | ||
XY?0=function code | XY?0=function code | ||
Revision as of 23:51, 6 January 2023
On entry:
XY?0=function code
XY?0=0+n use 7-bit BCD date block
XY?0=8+n use 8-bit BCD date block
XY?0=0 XY?0=8 Read as 25-character string
XY?0=1 XY?0=9 Read as 7- or 8-byte BCD block
XY?0=2 XY?0=10 Convert 7- or 8-byte BCD block at XY+1 to string
XY?0=3 Read as 5-byte centisecond time
XY?0=3 Read 25-character string from file server (ANFS 4.2x)
XY?0=4 Read BCD clock value from file server (ANFS)
XY?0=4 Return "hh:mm:ss DDD dd-mm-yy tt",CR
where tt is temperature. (I2C Control ROM)
XY?0=5
XY?0=6
XY?0=7
On entry:
XY?0=0: Return clock value as string
XY?0=8: Return clock value as string
On exit:
XY+0..24: CR-terminated string
On entry:
XY?0=1: Return 7-byte BCD clock value
XY?0=9: Return 8-byte BCD clock value
On exit:
XY+0..6: 7-byte BCD clock value
XY+0..7: 8-byte BCD clock value
On entry:
XY?0=2: Convert 7-bit BCD to string
XY+1..7: 7-byte BCD clock value
XY?0=10: Convert 8-bit BCD to string
XY+1..8: 8-byte BCD clock value
On exit:
XY+0..24: CR-terminated string
On entry:
XY?0=3: Return 5-byte centisecond clock value
On exit:
XY?0..4: Number of centiseconds since 00:00:00 01-Jan-1900
On entry:
XY?0=3: Return clock value as string from file server (ANFS 4.2x)
On exit:
XY+0..24: CR-terminated string
On entry:
XY?0=4: Return BCD clock value from file server (ANFS).
On exit:
XY+0..6: 7-byte BCD clock value
On entry:
XY?0=4: Return time, date and temperature string (I2C).
On exit:
XY+0..24: CR-terminated string
Data format
The date string format is "DDD,dd mmm yyyy.hh:mm:ss". The punctuation is normally irrelevant, the position of the component values is fixed. BCD date block format: +0 year &00-&99 +1 month &01-&12 +2 date &01-&31 +3 day &01-&07 Sun-Sat or &00 for unsupported +4 hour &00-&59 +5 minute &00-&59 +6 second &00-&59 +7 century &19-&20, if omitted, year is 1980-2079 BCD alarm block format: +0 hour &00-&59 or &C0-&FF for 'any' +1 minute &00-&59 or &C0-&FF for 'any' +2 second &00-&59 or &C0-&FF for 'any'
Implementation
On a system without a Real Time Clock, the MOS passes OSWORD 14 to sideways ROMs for support.
Master MOS
The Master MOS 3 and MOS 4 implements subcalls 0,1,2. Unpatched versions always consistantly return the year in the date string as 19xx. This can be repaired with:
Read time string to T$ IF MID$(T$,14,1)<"8":T$=LEFT$(T$,11)+"20"+MID$(T$,14)
ANFS
Master ANFS 4.2x implements subcalls 0,1,3,4 and calls OSWORD 14,2 to convert the result of subcall 0 and 3 to a string. BBC ANFS 4.0x and 4.1x only implements OSWORD 14,4.
The ANFS implementation fails in a predictable manner with dates after 1996. The returned date is ((year-1981) DIV 16)*16+date and the returned year is (year-1981) AND 15. The date can be repaired across the whole date range with:
date =BCDtoBIN(returned_date) AND 31 month=BCDtoBIN(returned_month) year =(BCDtoBIN(returned_date) AND &E0) DIV 2 + BCDtoBIN(returned-year)+1900
SoftRTC
The SoftRTC module stores the time and date with the system TIME timer. It implements subcalls 0,1,2 and 8,9,10. The SoftRTC module included in HADFS only implements subcalls 0,1,2 with the date set with *SETDATE.
See Also
Jgharston 12:56, 26 May 2009 (UTC) Jgharston (talk) 06:45, 12 April 2020 (CEST)
