Difference between revisions of "OSBYTE &00"

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(OSBYTE &00 (0) - Identify Host/Operating System)
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[[Category:OSBYTE]]
 
[[Category:OSBYTE]]
 
===OSBYTE &00 (0) - Identify Host/Operating System===
 
===OSBYTE &00 (0) - Identify Host/Operating System===
  On entry, X=0  - Generate error giving host and OS type
+
  On entry, X=0  - Generate error number 247 giving host and OS type
 
           X<>0 - Return host/OS in X
 
           X<>0 - Return host/OS in X
 
   
 
   
 
  On exit,  X=host/OS type:
 
  On exit,  X=host/OS type:
+
     0 Electron                 8 UNIX or UNIX-type system
     0 Electron
 
 
     1 BBC
 
     1 BBC
 
     2 BBC B+
 
     2 BBC B+
 
     3 Master 128
 
     3 Master 128
     4 Master ET
+
     4 Master ET                 28 Commodore 64/128
     5 Master Compact
+
     5 Master Compact           29 Texas Instruments calculator
     6 Arthur or RISC OS
+
     6 Arthur or RISC OS         30 Amstrad CPC
     7 Springboard
+
     7 Springboard               31 Sinclair ZX Spectrum
    8 UNIX or UNIX-type system
 
  28 Commodore 64/128
 
  29 Texas Instruments calculator
 
  30 Amstrad CPC
 
  31 Sinclair ZX Spectrum
 
 
  >=32 IBM PC-type system (DOS, Windows, etc.)
 
  >=32 IBM PC-type system (DOS, Windows, etc.)
  

Revision as of 22:25, 26 June 2017

OSBYTE &00 (0) - Identify Host/Operating System

On entry, X=0  - Generate error number 247 giving host and OS type
          X<>0 - Return host/OS in X

On exit,  X=host/OS type:
   0 Electron                  8 UNIX or UNIX-type system
   1 BBC
   2 BBC B+
   3 Master 128
   4 Master ET                 28 Commodore 64/128
   5 Master Compact            29 Texas Instruments calculator
   6 Arthur or RISC OS         30 Amstrad CPC
   7 Springboard               31 Sinclair ZX Spectrum
>=32 IBM PC-type system (DOS, Windows, etc.)

Implementations

Early documentation refers to OSBYTE 0 as returning the OS version. As more systems were developed, it became more correct to refer to it returning a value indicating the host. For example, code running on a second processor will always be told what the I/O host is regardless of what the host is and what the second processor is.

Platform capabilities

Over time the OSBYTE 0 return value has evolved to become a bitmap representing the capabilities of the host system, primarily of the file system structure.

  • %000x0xxx Filenames are directory.filename/extension, eg BBC, RISC OS
  • %000x1xxx Filenames are directory/filename.extension, eg Unix, CP/M
  • %nnnxxxxx Filenames are directory\filename.extension, eg DOS, Windows

This can also be represented as:

  • %000x0xxx Directory seperator is '.'
  • %000x1xxx Directory seperator is '/'
  • %nnnxxxxx Directory seperator is '\'
  • %000x0xxx Extension seperator is '/'
  • %nnnxnxxx Extension seperator is '.'

This allow programs to use code similar to the following:

  A%=0:X%=1:os%=((USR&FFF4)AND&FF00)DIV256
  d$=".":s$="/":IF(os%AND-24):d$="/":s$=".":IF(os%AND-32):d$="\"
  filename$=dir$+d$+name$+s$+ext$

See also

Jgharston 22:41, 6 September 2007 (BST)