83Plus:BCALLs:50E9 - Revision history

FloppusMaximus: categorize this under Link also

2006-11-06T22:16:37Z

categorize this under Link also

FloppusMaximus: This is about the TI-Keyboard, folks

2006-11-06T22:03:38Z

This is about the TI-Keyboard, folks

Brandonw: wrong OS version

2006-11-06T05:10:08Z

wrong OS version

Brandonw at 05:09, 6 November 2006

2006-11-06T05:09:01Z

New page

[[Category:83Plus:BCALLs:By Name|LinkReceive]]
[[Category:83Plus:BCALLs:By Address|50E9 - LinkReceive]]
== Synopsis ==
'''Unofficial Name:''' LinkReceive

'''BCALL Address:''' 50E9

Receives a series of bytes from the serial I/O port using either port 0 or the link assist, whichever is supported.

=== Inputs ===
* None

=== Outputs ===
* A contains status code

=== Destroys ===
* Unknown

== Comments ==
I have no idea what this function does. Possible status codes returned are:
* 00 = link transmission error, possibly timeout.
* 01 = byte received and was 0E0h.
* 02 = byte received and was not 0E0h.
* 0F9h = busy receiving a byte.
* 0FAh = byte received and was not 0E0h.
* 0FBh = byte received and was 0E0h.
* 0FEh = byte received and was not 0E0h.
* 0FFh = unknown error.

== Links ==
A full disassembly of this entry point on OS 2.40 is [http://www.brandonw.net/calcstuff/50E9.txt here].

@@ Line 1: / Line 1: @@
-[[Category:83Plus:BCALLs:By Name:Input|KeyboardGetKey]] [[Category:83Plus:BCALLs:By Name|KeyboardGetKey]] [[Category:83Plus:BCALLs:By Address|50E9 - KeyboardGetKey]]
+[[Category:83Plus:BCALLs:By Name:Input|KeyboardGetKey]] [[Category:83Plus:BCALLs:By Name:Link|KeyboardGetKey]] [[Category:83Plus:BCALLs:By Name|KeyboardGetKey]] [[Category:83Plus:BCALLs:By Address|50E9 - KeyboardGetKey]]
 == Synopsis ==
 '''Unofficial Name:''' KeyboardGetKey

← Older revision		Revision as of 05:10, 6 November 2006
Line 29:		Line 29:

	== Links ==		== Links ==
−	A full disassembly of this entry point on OS 2.40 is [http://www.brandonw.net/calcstuff/50E9.txt here].	+	A full disassembly of this entry point on OS 2.41 is [http://www.brandonw.net/calcstuff/50E9.txt here].

@@ Line 1: / Line 1: @@
-[[Category:83Plus:BCALLs:By Name|LinkReceive]]
+[[Category:83Plus:BCALLs:By Name:Input|KeyboardGetKey]] [[Category:83Plus:BCALLs:By Name|KeyboardGetKey]] [[Category:83Plus:BCALLs:By Address|50E9 - KeyboardGetKey]]
-[[Category:83Plus:BCALLs:By Address|50E9 - LinkReceive]]
 == Synopsis ==
-'''Unofficial Name:''' LinkReceive
+'''Unofficial Name:''' KeyboardGetKey
 '''BCALL Address:''' 50E9
-Receives a series of bytes from the serial I/O port using either port 0 or the link assist, whichever is supported.
+'''Minimum OS Version:''' 1.15
 === Inputs ===
@@ Line 13: / Line 14: @@
 === Outputs ===
 * A contains status code
 === Destroys ===
-* Unknown
+* AF, BC, DE, HL
 == Comments ==
-I have no idea what this function does. Possible status codes returned are:
+This B_CALL was introduced in OS 1.15.  Programs should check the OS version before attempting to use this routine.
-* 00 = link transmission error, possibly timeout.
-* 01 = byte received and was 0E0h.
+Keep in mind that the keyboard communicates using a truly horrible perversion of the DBUS protocol, which works as follows:
-* 02 = byte received and was not 0E0h.
+* The keyboard sends the byte E0.
-* 0F9h = busy receiving a byte.
+* It pulls both link lines low simultaneously for a short time (i.e., flags a DBUS error.)
-* 0FAh = byte received and was not 0E0h.
+* It sends the byte 01h.
-* 0FBh = byte received and was 0E0h.
+* Finally, it sends the scancode or modifier mask.
-* 0FEh = byte received and was not 0E0h.
+As a result, there are a variety of possible error conditions.
-* 0FFh = unknown error.
 == Links ==
 A full disassembly of this entry point on OS 2.41 is [http://www.brandonw.net/calcstuff/50E9.txt here].