OSBYTE &81
OSBYTE &81 (129) - Read Key with Time Limit or Machine Type. Called by BASIC's =INKEY function.
Action: Read key with time limit
X=0..255
Y=0..127
On exit C=0 character read, Y=0, X=character read
C=1, Y=255 timed out
C=1, Y=27 ESCAPE was pressed
Action: Read OS version
X=0
Y=255
On exit X=value identifying OS
X=&00 BBC B with OS 0.10
X=&00 RM Nimus
X=&01 Acorn Electron OS
X=&FF BBC Micro OS 1.00/1.20/1.23, Reuters OS R0.3 with *UK
X=&FE BBC Micro (American OS A1.0), Reuters OS R0.3 with *US
X=&FE NetBSD
X=&FD Master 128 MOS 3.20/3.50
X=&FC BBC Micro (West German MOS) - see note
X=&FC Windows 32
X=&FB BBC B+ 64/128 (OS 2.00)
X=&FB Beos (Brandy Basic)
X=&FA Acorn Business Computer OS 2.00
X=&FA Cambridge Workstation OS 2.10
X=&FA DOS with Brandy BASIC
X=&F9 Linux
X=&F8 MacOS X (Brandy Basic)
X=&F7 Master ET MOS 4
X=&F7 FreeBSD
X=&F6 OpenBSD
X=&F5 Master Compact MOS 5
X=&F5 Amiga (Brandy Basic)
X=&F4 Master 128 MOS 3.26
X=&Ex Spectrum
X=&Dx Amstrad 464/664/6128, etc.
X=&Cx Commodore 64/64+/128, etc.
X=&Ax ARM-based systems
X=&A0 Arthur 1.20
X=&A1 RISC OS 2.00
X=&A2 RISC OS 2.01
X=&A3 RISC OS 3.0x
X=&A4 RISC OS 3.1x
X=&A5 RISC OS 3.50
X=&A6 RISC OS 3.60
X=&A7 RISC OS 3.7x
X=&A8 RISC OS 4.0x
X=&A9 RISC OS 4.3x
X=&AA RISC OS 5.xx
X=&AF Springboard (An ARM-based development system plugged into a PC)
X=&8x TI Calculator
X=&68 6809 system
X=&63 6309 system
X=&73 BBC BASIC for ARM CPU on SDL abstraction (ie ASC"s")
X=&57 BBC BASIC for Windows (ie ASC"W")
X=&53 BBC BASIC for Intel CPU on SDL abstraction (ie ASC"S")
The known examples of German BBC MOS return X=&FF.
Action: Scan for a range of keys
X=1..127 lowest internal key number to start at EOR &7F
Y=255
On exit X=internal key number pressed (or 255 for none)
Action: Scan for a particular key
X=128..255 internal key number to scan for EOR &80
Y=255
On exit X=Y=0 for as not pressed
X=Y=255 the key was being pressed
See Also
Jgharston 21:56, 26 May 2009 (UTC) Jgharston (talk) 05:20, 23 June 2018 (CEST)
