isn't it 1024 bit?

It is quite easy, as you can see:

Conversion of an TInspire CX to an TInspire CX CAS

Program-Sources Download …
• (1) software „nLaunch“ from
http://tiplanet.org/forum/archives_voir.php?id=12105
• (2) software „TNOC“ from
http://tiplanet.org/forum/archives_voir.php?id=1922&short=1
• (3) of TInspireCX CAS-update from
http://education.ti.com/download/...
actual version: TI-NspireCXCAS-3.2.3.1233.tcc
• (4) of TInspire Link software from
http://education.ti.com/de/deutschland/software/details/en/.../ti-nspire_computerlink
actual ver.: TI-Nspire_Computer_Link_3.2.0.123.exe

Creation of necessary update
run TNOC_en.exe
• (1) choose „Open“ and put in path to TInspireCX CAS-update
• (2) activate checkbox „Delete boot2“
• (3) execute „Process“
• (4) result: in folder of original TInspireCX CAS-update-file (e.g. TI-NspireCXCAS-3.2.3.1233.tcc) now exists a new file with „originalname“_b.tcc (e.g. TI-NspireCXCAS-3.2.3.1233_b.tcc).
• (5) this file has to be renamed to „phoenix.tns“

Connect TInspire with PC
• (1) connect handheld with PC
• (2) create folder „nLaunch“ on handheld using TI Link-software
• (3) in the lower panel (TI-Nspire file browser) right-click, New Folder, "nLaunch"
• (4) copy file „phoenix.tns“ to folder „nLaunch“ on handheld
• (5) if exist: copy files „nLaunch.tns“ and „preloader.tns“ from PC-folder „nLaunch“ to handheld-folder „nLaunch“

Reboot to delete OS
• (1) reboot handheld: press reset-button at backside of device and at same time buttons „doc“ + „enter“ + „EE“
• (2) release reset-button
• (3) release three buttons
• (4) handheld reboots and stops with selection 1-4.
• (5) choose button 2: „Delete operating system“
• (6) confirm with button 1
• (7) handheld deletes OS and stops, showing: „Press any key to restart“
• ( execute restart („enter“), handheld stops, showing: „Operating System not found. Install OS now“

Installation of CAS
• (1) choose handheld in TInspire-Linksoftware at bottom right edge, (probably do „Aktualisieren“) and „Auswählen“:
• (2) choose „Extras“ at top, „Handheld-BS installieren“:
• (3) choose from PC-folder „nlaunch“ file „nLauch.tco“:
• (4) installation of new CAS-OS with „BS installieren“ and confirm „Ja“:
• (5) installation of new CAS-OS starts
• (6) PC shows „Fehler“: IGNORE ERROR MESSAGE !!!
• (7) The new CAS-operating system is installed correctly on TInspireCX (error message does not matter):

do setup
• do setup on handheld: choose „Language“ and „Size“ of writing

do CAS calculations
• do classical calculations, e.g.: factor, expand, integration

Yeah you might want to check the last post date before posting in the future, to avoid thread necromancy, although there are exceptions (no, not Halloween ).