Editing SmartBox OS (section)

=== internal_vec and unknownjob_vec ===

The main operation of extended JobCalls rely on patching some
vectors, two in fact.  These two are unknownjob_vec and internal_vec. 
unknownjob_vec is the one which the OS calls to actually tell everybody that
a JobCall has been requested which it does not know about (the JobCall MUST
have been claimed before hand with OS_CALLOS, function 1, or else it is not
passed on).  internal_vec is the one which the OS calls in request to a
NameCode or CodeName.

The vectors are defined as thus:

==== internal_vec ====

===== internal_vec 0 =====

{|class="calltable"
|Purpose||
Nothing
|-
|Entry||
* A = 0
* X, Y, c, z = undefined
|-
|Exit||
Leave everything as it is and exit straight away
|-
|Note||
Used for claimed calls
|}

===== internal_vec 1 =====

{|class="calltable"
|Purpose||
NameCode request
|-
|Entry||
* A = 1
* X, Y, c, z = undefined
* jobin_buf contains JobName (CR terminated)
|-
|Exit||
* if JobName recognised then
** A = 0
** first byte of jobin_buf contains matched JobCode
* if JobName not recognised then
** A = 1
** X, Y, c, z = undefined
|}

===== internal_vec 2 =====

{|class="calltable"
|Purpose||
CodeName request
|-
|Entry||
* A = 2
* X, Y, c, z = undefined
* jobin_buf contains JobCode
|-
|Exit||
* if JobCode recognised then
** A = 0
** jobin_buf contains matched JobName (CR terminated)
* if JobCode not recognised then
** A = 2
** X, Y, c, z = undefined
|}

All other calls (ie.  not 0, 1 or 2 should be passed on straight
away for future expansion)

==== unknownjob_vec ====

{|class="calltable"
|Purpose||
To pass on unknown JobCalls to the correct owner
|-
|Entry||
* A = environment (0 = internal call, 1 = serial call)
* Y = JobCode
* X = JOB ID of owner
* c, z = undefined
|-
|Exit||
* if jobcode yours then
** if wrong environment then
*** A = 1
*** Y = 0
*** X, c, z = undefined
** if right environment then
*** perform function
*** A = 0
*** Y = 0
*** X, c, z = undefined
* if jobcode not yours then
** pass on with registers unaltered
|}