AppleTalk Undocumented Functionality

Here is some AppleTalk functionality not documented in the APDA Apple II AppleShare Programmer's Guide.

Init (function $01)

The APDA documentation mentions the Init function, then says never to call it and gives no parameter list for it. Here is its parameter list:

Pos Name Size Value
$00 Async Flag Byte $00 (Synchronous only)
$01 Command Byte $01
$02 Result Code Word
$04 Init flags Byte See below.
$05 P8 Entry Long P8 MLI entry address
$09 Node number Byte Preferred node number or $00
$0A Unknown Word ?

Init flags:

Value Function
$00 Partial init, no MLI global page update
Used during netboot
$80 Full init, no MLI global page update
Used during IIgs boot
$40 Full init, MLI global page update
Used by ATINIT and boot block LOGON

FIUserPrefix (function $2A)

The Reserved byte high bit is a direction indicator and is used by the LOGON program to set the User Prefix when a user volume is mounted.

Specifically, Logon sets it to $AA, but only the high bit matters.