83Plus:Ports:00 - Revision history

Fghsgh: oops I was wrong, Undo revision 11679 by Fghsgh (talk)

2020-03-17T15:14:33Z

oops I was wrong, Undo revision 11679 by Fghsgh (talk)

2020-03-17T15:13:21Z

set reset swapped around?

2011-08-09T16:38:45Z

Grammar and standards conformance

2009-02-27T06:14:17Z

‎Read Values: bit 6

2007-07-03T10:20:44Z

‎Data transfer

2007-07-03T10:19:04Z

‎Data transfer

2007-06-30T14:10:57Z

Little more clarification

2006-05-13T19:45:41Z

‎Data transfer

2006-05-13T19:07:35Z

‎Data transfer

2006-05-13T19:06:59Z

‎Data transfer

@@ Line 8: / Line 8: @@
 === Read Values ===
-* Bits 0 and 1: These bits indicate the state of the link port's two lines. If a bit is reset that indicates the line is high, and if it is set that indicates the line is low. When idle (no transfer in progress, no cable plugged in, etc), both lines are usually high. When a cable is connected on both ends, a line reads high if and only if both ends have set the line high. The line will read low if either calculator sets it low. Bit 0 is the tip and bit 1 is the ring.
+* Bits 0 and 1: These bits indicate the state of the link port's two lines. If a bit is set that indicates the line is high, and if it is reset that indicates the line is low. When idle (no transfer in progress, no cable plugged in, etc), both lines are usually high. When a cable is connected on both ends, a line reads high if and only if both ends have set the line high. The line will read low if either calculator sets it low. Bit 0 is the tip and bit 1 is the ring.
 *'''83+ only:''' Bit 2: Set means link receive assist is active.
 *'''83+ only:''' Bit 3: Set when link assist has received a complete byte. The only way to reset this bit is to read [[83Plus:Ports:05|port 5]].

@@ Line 8: / Line 8: @@
 === Read Values ===
-* Bits 0 and 1: These bits indicate the state of the link port's two lines. If a bit is set that indicates the line is high, and if it is reset that indicates the line is low. When idle (no transfer in progress, no cable plugged in, etc), both lines are usually high. When a cable is connected on both ends, a line reads high if and only if both ends have set the line high. The line will read low if either calculator sets it low. Bit 0 is the tip and bit 1 is the ring.
+* Bits 0 and 1: These bits indicate the state of the link port's two lines. If a bit is reset that indicates the line is high, and if it is set that indicates the line is low. When idle (no transfer in progress, no cable plugged in, etc), both lines are usually high. When a cable is connected on both ends, a line reads high if and only if both ends have set the line high. The line will read low if either calculator sets it low. Bit 0 is the tip and bit 1 is the ring.
 *'''83+ only:''' Bit 2: Set means link receive assist is active.
 *'''83+ only:''' Bit 3: Set when link assist has received a complete byte. The only way to reset this bit is to read [[83Plus:Ports:05|port 5]].

@@ Line 21: / Line 21: @@
 == Comments ==
-=== Ti-OS interference ===
+=== TI-OS Interference ===
 One thing to keep in mind when writing link port related software is that the Ti-OS checks for silent transfers in the background of input routines. When two calculators are connected and one pulls a line low, the other calculator will respond by pulling the other line low to acknowledge that it has received a bit. Even when the other calculator is running an assembly program that uses the getkey romcall. This phenomenon is known to cause severe headaches for programmers who attempt to write synchronization routines :).
-=== Data transfer ===
+=== Data Transfer ===
 Transferring an entire byte requires you to implement some form of protocol. Examples include TI's official linking protocol, [http://www.ticalc.org/archives/files/fileinfo/277/27718.html Michael Vincent's TachyonLink protocol] and [http://bell.timendus.com/ Timendus' Bell library].

@@ Line 12: / Line 12: @@
 *'''83+ only:''' Bit 3: Set when link assist has received a complete byte. The only way to reset this bit is to read [[83Plus:Ports:05|port 5]].
 * Bit 4 and 5: Bits 4 and 5 indicate which lines are pulled low by the calculator (unlike bits 0 and 1 they are not influenced by the other calculator). A 1 bit indicates your calculator is holding the line low. A 0 bit indicates your calculator is not holding the line low. (When both calculators have a 0 bit here, the corresponding line will read 1.) In other words, these bits reflect bits 0 and 1 from the most recent write to this port.
 === Write Values ===

@@ Line 28: / Line 28: @@
 Other useful information on linking in general:
 *  [http://www.ticalc.org/archives/files/fileinfo/247/24750.html TI Link Protocol & File Format Guide]
-*  [http://www.ticalc.org/archives/files/fileinfo/294/29418.html Ti-83 Link Port Tutorial]
+*  [http://www.ticalc.org/archives/files/fileinfo/294/29418.html Ti-83 Link Port Tutorial] (note that this deals with the TI-83, not the 83 Plus, where the the hardware is [[83:Ports:00|somewhat different]].)
 *  [http://www.ticalc.org/archives/files/fileinfo/242/24244.html All about the Ti-86 link port]
 *  [http://bell.timendus.com/ Bell] and [http://clap.timendus.com/ CLAP] projects