0x90 - Open Course Gump
-----------------------
Client->Server:No
Server->Client:Yes
Length:0x13

byte 0x90
uint serial
ushort gumpArtworkID (0x139D)
ushort x1
ushort y1
ushort x2
ushort y2
ushort mapWidth (in pixels)
ushort mapHeight (in pixels)