Difference between revisions of "INKEY"
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&57 BBC BASIC for Windows (ie ASC"W") | &57 BBC BASIC for Windows (ie ASC"W") | ||
− | Depending on what the program needs to know, [[OSBYTE &00]] | + | Depending on what the program needs to know, [[OSBYTE &00]] is usually the more appropriate call to make. |
==See Also== | ==See Also== |
Revision as of 17:37, 17 December 2015
INKEY and INKEY$ are BASIC functions to:
- wait a specified time for a character from the input stream
- test for a keypress
- return a value indicating the machine host/operating system type
Availability | Present in all versions of BBC BASIC. | |
Syntax | <numeric> = INKEY <numeric>
|
<string> = INKEY$ <numeric>
|
Token (hex) | A6 (function)
|
BF (function)
|
Description | Reads an character from the input stream. |
Contents
Description
INKEY
and INKEY$
call OSBYTE &81.
INKEY
returns a character or -1 for no character, INKEY$
returns a one-character string or a null string if nothing returned.
Wait for input character
Argument: >=0 Returns: >=0, character returned -1, timed out Example: key%=INKEY(200) REPEAT:k%=INKEY(10):PROCtick:UNTIL k%>-1 Some systems allow a delay value with b15 set to return a 16-bit "deep" keyvalue distinguishing between special keys, such as function keys, and top-bit characters.[1][2] Example: REPEAT:key%=INKEY(&80C8):UNTIL key%>-1 IF key%=&190 THEN PRINT "Shift-f0 pressed"
Scan for a particular key
Argument: -1..-128, negative key number Returns: TRUE, key pressed FALSE, key not pressed
Scan for a range of keys
Argument: -129...-255, lowest internal key number to start at EOR&7F Returns: internal key number pressed, or 255 for none
Check machine type
Argument: -256 Returns: A value indicating the host (I/O) machine type: &00 BBC B with MOS 0.10 &00 RM Nimus[3] &01 Acorn Electron MOS &FF BBC Micro OS 1.00/1.20 &FE BBC Micro (American MOS 1.10) &FE NetBSD &FD Master 128 MOS 3.20 &FC BBC Micro (West German MOS) &FC Windows 32 &FB BBC B+ 64/128 (MOS2.00) &FB Beos (Brandy Basic) &FA Acorn ABC &FA DOS with Brandy BASIC &F9 Linux &F8 MacOS X (Brandy Basic) &F7 Master ET OS 4.00 &F7 FreeBSD &F6 OpenBSD &F5 Compact &F5 Amiga (Brandy Basic) &F4 Master 128 MOS 3.26 &Ex Spectrum &Dx Amstrad 464/664/6128, etc. &Cx Commodore 64/64+/128, etc. &Ax Arthur/RISC OS &A0 Arthur 1.20 &A1 RISC OS 2.00 &A2 RISC OS 2.01 &A3 RISC OS 3.0x &A4 RISC OS 3.1x &A5 RISC OS 3.50 &A6 RISC OS 3.60 &A7 RISC OS 3.7x &A8 RISC OS 4.0x &A9 RISC OS 4.3x &AA RISC OS 5.xx &AF Springboard (INKEY-256 AND &F0)=&A0 gives TRUE for ARM hardware &57 BBC BASIC for Windows (ie ASC"W")
Depending on what the program needs to know, OSBYTE &00 is usually the more appropriate call to make.
See Also
- http://mdfs.net/Docs/Comp/BBC/Osbyte80
- http://mdfs.net/Docs/Comp/Acorn/HostVals
- http://mdfs.net/Docs/Comp/Acorn/Hosts
- What BASIC is running
- Negative INKEY numbers
References
- ↑ http://mdfs.net/Docs/Comp/KeyMap/Regular
- ↑ http://mdfs/net/System/C/Lib/console.txt
- ↑ Network User, Jan/Feb 1988, p9
Jgharston 12:27, 28 May 2009 (UTC)