OS_Vth, Verify tri-handle
Register parameters
RST 20H, DEFW $E006
IN: A = Tri-handle subtype TH_FILT ($F0), verify filter handle TH_WMG ($F1), verify wildcard manager handle TH_ALM ($F2), verify alarm handle IX = tri-handle OUT, if call successful: Fc = 0, handle OK. B = Bank H = Adress of high byte L = Segment OUT, if call failed: Fc = 1 A = RC_HAND, bad handle Registers changed after return: ...CDE../IXIY same AFB...HL/.... differentÂ