Difference between revisions of "OSWORD &62"

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[[Category:OSWORD]]
 
[[Category:OSWORD]]
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OSWORD &62 (98 ) - Access LVROM controller  
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OSWORD &62 (98 ) - Access LVROM controller VFS
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__TOC__
 
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==Specification==
 
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    Same format as ADFS call &72 (114)
 
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    On entry:
 
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        XY?0  = 0, returned result
 
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        XY!1  = data address
 
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        XY?5  = command
 
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        XY?6  = drive number in b5-b7, sector b16-b20 in b0-b4
 
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        XY?7  = sector number b8-b15
 
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        XY?8  = sector number b0-b7
 
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        XY?9  = number of sectors or 0
 
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        XY?10 = 0
 
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        XY!11 = data length if X%?9=0
 
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This is a standard SCSI command block. The drive number in XY?6 is ORed with
 
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the current drive. If VFS is not selected when the call is made, VFS is
 
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selected. Consequently, any code that calls OSWORD &62 must remember the
 
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current filing system and restore it afterwards. In practice it is easier
 
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to select VFS before calling OSWORD &62.
 
  
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===Commands===
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Same format as ADFS call &72 (114). Commands are:
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    &00=Test drive ready
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  &00=Test drive ready
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    &01=Seek track 0
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  &01=Seek track 0
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    &03=Request status
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  &03=Request status
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    &08=Read data
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  &08=Read sectors
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    &0B=Seek track
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  &1B=Stop/Start drive; stop if XY?9=0, start if XY?9=1
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    &1B=Stop/Start drive; stop if XY?9=0, start if XY?9=1
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  &C8=Read F-code result from LVDOS
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    &C8=Read F-code result from LVDOS
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  &CA=Transmit F-code to LVDOS
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    &CA=Transmit F-code to LVDOS
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Results are:
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  &02=Drive door open
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===Results===
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  &03=Media error, eg disk dirty
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    &00=Ok
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  &05=Bad SCSI command
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    &02=Drive door open
 
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    &03=Media error, eg disk dirty
 
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    &05=Bad SCSI command
 
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    &04=Not ready
 
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    &40=Write protected
 
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    &48=CRC error
 
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    &50=Sector not found
 
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    &60=Bad command
 
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    &61=Bad address
 
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    &63=Volume error
 
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    &65=Bad drive
 
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    &6F=Abort
 
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The result byte can be preloaded with a value to return if no OSWORD &62
 
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routine exists. For instance, preloading the result with &00 makes all such
 
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failed calls appear to succeed, preloading with &50 makes all calls appear
 
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to return 'Sector not found'.
 
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===Coding===
 
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The following routine can be used to perform an OSWORD &62 call. It requires
 
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X%=>15-byte control block, Y%=X%DIV256.
 
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    DEFFNlvfs(cmd%,addr%,num%,sect%,drv%):LOCALfs%
 
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    fs%=FNfs:IFfs%<>10:*FX143,18,10
 
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    X%?0=0:X%!1=addr%:X%?5=cmd%:X%?6=drv%*32+((sect%AND&1F0000)DIV65536)
 
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    X%?7=((sect%AND&FF00)DIV256):X%?8=sect%:X%!9=0:X%!11=num%
 
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    A%=&62:CALL&FFF1:A%=?X%:IFfs%<>10:OSCLI"FX143,18,"+STR$fs%
 
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    =A%
 
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    DEFFNfs:LOCALA%,E%,Y%:=(USR&FFDA)AND&FF
 
  
 
==See Also==
 
==See Also==
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* [[OSWORD &72]]
 
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* http://mdfs.net/Docs/Comp/BBC/Osword/Osword62
 
 
* http://mdfs.net/Docs/Comp/BBC/Oswords
 
* http://mdfs.net/Docs/Comp/BBC/Oswords
  
 
[[User:Jgharston|Jgharston]] 14:00, 26 May 2009 (UTC)
 
[[User:Jgharston|Jgharston]] 14:00, 26 May 2009 (UTC)

Revision as of 01:13, 8 March 2015

OSWORD &62 (98 ) - Access LVROM controller VFS 

Same format as ADFS call &72 (114). Commands are:
 &00=Test drive ready
 &01=Seek track 0
 &03=Request status
 &08=Read sectors
 &1B=Stop/Start drive; stop if XY?9=0, start if XY?9=1
 &C8=Read F-code result from LVDOS
 &CA=Transmit F-code to LVDOS
Results are:
 &02=Drive door open
 &03=Media error, eg disk dirty
 &05=Bad SCSI command

See Also

Jgharston 14:00, 26 May 2009 (UTC)

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