OS_Gth, allocate tri-handle

RST 20H, DEFW $E206

IN:

     A = tri-handle subtype
           TH_FILT ($F0), allocate filter handle
           TH_WMG ($F1), allocate wildcard manager handle
           TH_ALM ($F2), allocate alarm handle
     B = Bank where code is to be called
     H = High byte of adress (Low byte is given by the reason code after RST 30h)
     L = Segment where to bind bank

     Fc = 0
     IX = tri-handle

     Fc = 1
          A = RC_ROOM, failed to allocate tri-handle

     ..BCDEHL/..IY same
     AF....../IX.. different

Internal operating system usage.
This call specifies a code area to be called by the RST $30 followed by a reason code (the low byte address). When using this call, IX is the handle. Those values are remembered by calling OS_Vth with the correct handle (IX) and the correct subtype (A).

Related system calls:

OS_Vth, verify tri-handle
OS_Fth, free tri-handle