• New custom ABS plastic enclosure with externally accessible battery compartmnet for easy battery replacement.
• 4 times the internal memory space – 512kB vs 128kB, allowing room for many more objects to be stored, up to over 33,000.
  
• Memory is Flash type – this means it is re-programmable in the unit.  No need to physically replace an OTP (One Time Programmable) EPROM in order to upgrade. Connect the XP4 to your PC and run the XP4_Boot-Flash_Utility to upgrade. Flash memory has virtually unlimited reprogramming cycles.
  
• Encoder ‘Fast-Tracking’ – This is the first important upgrade supported in version 4.2. It allows use of very high resolution encoders, up to 24576 count without the problem of loosing encoder counts if the scope is moved quickly. It is also useful on very small scopes that can move quickly. This feature operates only while external 12 volt power is applied because it uses more power than an internal 9 volt battery can supply.
  
• The latest version of the software (5.03) includes support for the UGC catalog of almost 13,000 galaxies in the northern hemisphere, and 2554 stars of the Flamsteed catalog. It also has support for lunar rate tracking when used with the Sky Tracker telescope drive system.
  

At this time the XP4 Boot-Flash Utility is available for download. With it you will be able to upgrade to the most recent version (5.03 SP03). With this version you will be able to select from a number of astronomical catalogs.

XP4 supports the following astronomical catalogs, collectively almost 33,000 objects:

• Abell_Planetary_Neb*- A list (82 objects) of old and ancient plantetary nebulae research by a well known astronomer, George Abell. As these planetaries are ancient, they provide a nice challenge as most are extended and of low surface brightness.
• Arp_Galaxies- A list of 338 galaxies showing different aspects of peculairity studied by Halton Arp.
• Bayer_Stars- 1564 stars cataloged by Greek letter and constellation.
• Double_Stars- A collection of 600 fine double stars provided with permision from the Saguaro Astonomy Club.
• Flamsteed_Stars- 2554 stars cataloged by number and constellation.
• Hickson*- A list of small compact galaxy groups, which presents a challenge for the observer. This list, 100 groups, was compiled by a Canadian professional astronomer, Paul Hickson, for research on discordant redshifts.
• Messier- The famous catalog of Charles Messier. 109 bright deep sky objects.
• Named_Deep_Sky- 135 deep sky objects by common name.
• Named_Stars- 142 stars by common name.
• NGC- Entire NGC catalog of 7840 deep sky objects.
• UGC- Entire UGC (Uppsala General Catalog) catalog of 12,921 northern hemisphere galaxies.
• Herschel 400- The 400 most impressive deep sky objects in William Herschel's catalog of over 2500. Cataloged by NGC number.
• IC- Index Catalog of 5250 deepsky objects.
• Barnard- 343 Dark Nebula
• Berkley- 86 Open Clusters
• Collinder- 471 Open Clusters
• Trumpler- 34 Open Clusters
• Planets- 8 planets including Pluto
• Special Objects- 59 user defined object positions. Enter RA and declination through keypad.

* Well written Observing Guides for the Hickson and Abell Planetary Nebulae, including finder charts, sketch and observing notes are available at www.faintfuzzies.com. The Arp Observer's Guide is due for release in mid-2007.