Upgrade Guide - Prolifics

Processing Keyboard InputWith Timing Interval SetIf you have a KBD_DELAY entry in your video file, you can specify key sequences in thekey translation file that are substrings of other sequences. For example, the sequencesESC and ESC [ C can both have logical values, even though one is a substring of theother. In this case, Panther waits the specified timing interval, as indicated in theKBD_DELAY entry, between processing characters to determine if a character is a singlekeystroke or belongs to a sequence of keystrokes.Key RoutingThe third step in processing keyboard input is handled by the library functionsm_input. This function calls sm_getkey to obtain the translated value of the key. Itthen decides what to do based on the following rules:Value Greater Than 0x1ffIf the logical value is greater than 0x1ff, sm_input returns the value as the returncode.Value Between 0x01 and 0x1ffIf the value is between 0x01 and 0x1ff, the key is translated via the key translation file.The processing of the key is then determined by a routing table. You can alter thedefault behavior of keys (cursor control) within this range with the library functionsm_keyoption as well as set the routing information for a particular key. The routingvalue consists of two bits, examined independently, so four different actions arepossible:! If neither bit is set, the key is ignored.! If the EXECUTE bit is set and the logical value is in the range 0x01 to 0xff, it iswritten to the screen (as interpreted by the GRAPH entry in the video file, if oneexists). If the value is in the range 0x100 to 0x1ff, the appropriate action (Tab,field erase, etc.) is taken.! If the RETURN bit is set, sm_input returns the logical value to the caller;otherwise, sm_getkey is called for another value.! If both bits are set, the key is executed and then returned.B-4 JAM Documentation: Internal I/O Processing