Editing SmartBox OS (section)

=== OS_READJOB and OS_SENDJOB ===

To send/receive data from the user (either internally or via the
serial port) you call OS_SENDJOB/OS_READJOB for the next byte.  If your
JobCall requires dynamic use of data, ie.  interaction, then a check of the
enviroment should be done to check the call came from the serial port.  One
example of this is the OS JobCall MultipleServer, which requires dynamic use
of sending a stream of data until a reaction from the user to tell it to
stop.

==== OS_READJOB: Read job value from the user ====

{|class="calltable"
|Entry||
* A, X, Y, c, z = undefined
|-
|Exit||
* A = byte read
* X, Y is preserved
* c, z = undefined
|-
|Note||
When coming from the serial port it waits for a character to be received, if you are doing a serial only call and wish to have a loop checking for a character from the user while doing "your own thing", then OS_READBYTE should be used.  For internal calls this reads data out of jobin_buf.
|}

==== OS_SENDJOB: Give a job value back to the user ====

{|class="calltable"
|Entry||
* A = byte to give
* X, Y, c, z = undefined
|-
|Exit||
* A, X, Y is preserved
* c, z = undefined
|-
|Note||
This will send either out to the serial port or place a byte in jobout_buf.
For internal calls this stores the value in jobout_buf, which is allocated 128 bytes, no bound checking is done so sending more than 128 bytes to OS_SENDJOB will cause corruption of some memory.
|}