OSWORD &7A (122) - Teletext commands
On entry: XY?0=command. The command is &00..&7F for Advanced Teletext commands, &80..&FF for standard commands: &00 - Read channel, returned to XY?1, 0=BBC1, etc. &01 - Set channel from XY?1, 0=BBC1, etc. &02 - Read record flag. Record in XY?1, returned flag in XY?2: b0=HOLD, b1=received, b2=being updated. &03 - Set record flag, record in XY?1, flag in XY?2 as above. &04 - Read a Page Grabber record. XY?1 contains record. Returns XY?2=magazine, XY?3=BCD page number, XY+4..5=sub-page, XY+6..7=I/O address to store page. &05 - Set a Page Grabber record, entry details as above. &06 - Read number of rows to be captured to XY?1. &07 - Set number of rows to be captured from XY?1. &08 - Read header line status to XY?1: &00=header off, &01=header on with clock, &FF=header on without clock. &09 - Set header line status from XY?1 as above. &0A - Read magazine for header display to XY?1. &FF means all headers. &0B - Set magazine for header display from XY?1 as above. &0C - Switch off teletext interrupts. &0D - Switch on teletext interrupts. &0E - Clear all Page Grabber records. &0F - Read Television Service Data Packet On exit: XY?1=magazine for initial page XY?2=BCD initial page number or &FF if none XY+3..4=initial page sub-code XY+5..6=network group identity XY?7=Time offset from Universal Coordinated Time: b0=1, b1=half hour, b2=1 hour, b3=2 hours, b4=4 hours, b5=8 hours, b6=add/subtract offset, b7=1. XY+8..10=BCD Modified Julian Time hi to lo XY+11..13=BCD Universal Coordinated Time hours, minutes, seconds. &10 - Clear Page Grabber record. &11 - Read Adapter status to XY?1: &00=on and connected, &01=on, no TV signal, &02=off, but connected, &FF=no adapter connected. &12 - Set Subtitle Enable flag On entry: XY?1=&00 to enable, &FF to disable, XY?2=subtitle magazine XY?3=BCD subtitle page. &13 - Set interrupt handling flag from XY?1: &00 to enable, &FF to disable. &14 - Enter Tuning routine. Exited by pressing SPACE. &15 - Return time from TSDP. On exit: XY+1..9="HH:MM:SS" string XY?10=flag, &00=ok, &FF=no time found. &16 - Return date from TSDP. On exit: XY+1..12="DD/MM/YYYY" string XY?12=flag, &00=ok, &FF=no date found. &17 - Check CRC. On entry: XY+1..2=>page data in I/O On exit: XY?3=result, &00=no CRC, &01=CRC ok, &FF=CRC failed. &18 - Download file from teletext. On entry: XY+1..2=>filename in I/O XY!3=load address XY!7=exec address XY?11=magazine number XY?12=BCD page number XY?13=&00 - Load to memory at OSHWM, &01 - Load to file load address XY?14=&00 - Reset default table, &01 Don't reset tables. &19 - De-Ham a byte at XY?1. On exit: XY?2=De-Hammed nybble and result. b0-b3 contain nybble, b4-b7=%1111 - unrecoverable error b4-b7=%0xx1 - recoverable error b4-b7=%x1x1 - single bit error b4-b7=%0xx0 - no error. &1A - Set emulation mode. On entry: XY?1=characters per line to receive, 40 for TFS mode, 42 for TTX mode. The two extra bytes at the beginning contain the magazine and row numbers. &1B - Read emulation mode. On exit: XY?1=characters per line that will be read, 40 for TFS or 42 for TTX.
&80 - Reload Last Page. &85 - Fetch Page. On entry: XY?1=page 100s XY?2=page 10s XY?3=page 1s XY?4=subpage 1000s XY?5=subpage 100s XY?6=subpage 10s XY?7=subpage 1s &86 - Chain page. Fetches the next page in a chain. &88 - Head of Chain. Follows the chain around until the head is reached. &89 - Test Arrived. On exit: XY?1=result: &00=last page requested not arrived, &FF=last page requested has arrived. &8A - Unlock Page. When a page has arrived, it becomes locked. This unlocks it and allows further update. &8B - Select Channel. Selects the channel in XY?1 (0-3). &8D - Read TSDP. On exit: XY+1..2=Television Service Data Packet. &8E - DeHam a Byte. The byte at XY?1 is dehamed and returned in XY?1, with flags as for &19 above. &8F - Transfer. The current page is transfered to the address in XY+1..4. &92 - Headers. On entry: XY+1..2=I/O address to display 32-character page header. &93 - What Channel. Returns the currently selected channel in XY?1.
Jgharston 13:16, 26 May 2009 (UTC)
Note: call 21 and 17 allow you to discover what adaptor you're using. See Micro User Aug 1989, "Updater"