EXSAS (Extended Scientific Analysis System) has been devoleped specifically for individual data interactive data analysis work on the ROSAT instruments (PSPC, HRI and WFC). EXSAS has been built on top of the well-known and widely accepted ESO-MIDAS environment. By construction EXSAS should be a lively and open-ended system, where applications can be easily modified and expanded according to specific needs. EXSAS "98 APR release" is available at I.R.A. on alpha workstations To work with MIDAS+EXSAS a personal username on alpha workstations. To start MIDAS you must enter the command: inmidas The program starts asking you the mumber/type of midas session. Answer a number between 0 to 99 if you are useing at a Work_station Answer a code between xx to zz if you are working at a terminal Then from the midas prompt type: set/context exsas The EXSAS User's Manual is available in three different forms: HTML and Postscript file Manuals in room 307 Contact Person: F.Tinarelli tinarelli@ira.inaf.it