View source for 83PCE:Hooks:0D0260Eh

[[Category:83PCE:Hooks:By_Name|Token Hook]] [[Category:83PCE:Hooks:By_Address|9BC8 - Token Hook]]
== Synopsis ==
'''Name:''' Token Hook

'''Hook Pointer Block Address:''' [[83Plus:RAM:9BC8|9BC8]]

'''Hook Enable BCALL:''' [[83Plus:BCALLs:4F99|4F99]]

'''Hook Disable BCALL:''' [[83Plus:BCALLs:4F9C|4F9C]]

'''Hook Call BCALL:''' ''(none known)''

'''Hook Active Flag:''' [[83Plus:Flags:35#Bit_0|0, (iy + 35h)]]

This hook allows you to change the strings displayed for TIOS tokens.

== Using the Hook ==
* DE = token number * 2
** 1-byte:     0000 to 01FE
** Matrix:     0200 to 0212
** List:       0214 to 021E
** Equation:   0220 to 025C
** Picture:    025E to 0270
** GDB:        0272 to 0284
** String:     0286 to 0298
** Output Var: 029A to 0312
** System Var: 0314 to 0382
** Format:     0384 to 03A8
** BB:         03AA to 0546 (or higher, depending on OS)
* HL = default string
** Change HL to display a different string, which you must copy to RAM

== Comments ==
In OS 1.15 this hook was modified to prevent apps from defining new tokens.  There are two checks in the token getting routine of OS 1.15: one which treats all undefined tokens as a question mark, and one which prevents the token hook from being run if the token is not in the standard OS 1.12 token set.

This was somewhat meta-fixed in OS 1.16 to the point that all of the original extended tokens can be used.  However, it still doesn't allow new tokens to be defined.

To summarize:
* On OS 1.14 and prior OS's - all BB tokens are reported as 03AA+2T, including hacked tokens.  This caused localizers to crash when they encountered the extended Symbolic tokens.
* On OS 1.15 - BB tokens after GarbageCollect are not passed to the token hook at all.  They are always displayed as a question mark.
* On OS 1.16, and future OS's - BC is the unmodified value as reported by 1.14 for all tokens up to the last actual token supported; DE is set to a value representing a question-mark.
* On OS 2.20, and future OS's - For the BB tokens after tGarbageCollect BC contains the unmodified value and DE=$0012. All EF tokens are put after these as if EF XX was BB 1XX.