When the supervirus Daemon began her Infection of the Guardian Collective, Prime Guardian Turbo -- not yet Infected -- had a new version of the Guardian protocol created, one that was immune to Daemon's influence.  But before Turbo could upload the protocol into himself or his successor, both were Infected.  So Turbo entrusted the new protocol and the task of stopping Daemon to another -- Guardian 640, Pentium.

Pentium returned to his home system, the Server, and had it fortified for viral attacks.  Then, he received word of the existence of a mythical artifact that had the capacity to destroy Daemon, a file called the Book of the Net -- the Cybernomicon.  Pentium set out to find the Book, but ran afoul of a viral army led by the virus siblings Michel Angelo and Melissa.  Pentium was able to find the Book, but not before the siblings destroyed his exploratory group and his way home.  Trapped on the viruses' ship, the SS Mitnick, Pentium dumped off the Book in their garbage pods and allowed himself to be captured.  When Angelo was unable to Infect Pentium, he destroyed his mind and had him dumped off the ship with the rest of the garbage.

The garbage pods landed in the small, backwater system of Mainframe, where the amnesiac Pentium was discovered.  Unable to remember who he was or what his format was (his Guardian nature was hidden to avoid detection by Daemon), the sprite was christened RAM by the Mainframers, due to the random bits of data that had been lodged in his head from Angelo's wrath.  The viruses tracked him to Mainframe and attacked, but Angelo's attack on RAM dislodged enough of the neural blocking to help RAM recall his format and his mission to find the Cybernomicon.

RAM helped the Mainframers drive off Angelo after crippling the virus, and then made an alliance with a sprite gunslinger who fell into Mainframe to escape the Guardians -- Nil Cipher.  Cipher didn't entirely trust RAM, but did help him stave off another attack by the viruses, and then again when the Cybernomicon was finally located in Mainframe.

Thanks to a Full Restore algorithm from the Book, RAM's memory was restored and he helped Cipher destroy Angelo.  The restored Pentium recruited Cipher and both returned to the Server to prepare for an attack on Daemon and vengeance strikes by the wrathful Melissa, who sought to avenge her brother's deletion.  The attack on the Supercomputer, however, is on hold until Pentium can locate the algorithm that will allow him to delete Daemon once and for all.

Pentium, prior to his restoration, had bronze skin and platinum hair, in a hairstyle not too dissimilar from Bob's (prior to his exile to the Web).  He has silver eyes and a rather unimpressive physique.  In place of his right arm, however, was a full robotic prosthesis, gold in color.  A gold monocle (glass-less) was fixed over his right eye.  This prosthesis served as Pentium's equivalent of a keytool, responding to the name 'Arm.'  Information could be printed across a holographic field in the monocle.

When his memory was restored, however, so was Pentium's arm, so the Cybernomicon converted 'Arm' into 'Armour', which covered parts of his right arm and his chest and back.  Metal was attached to the monocle, converting it into a halfmask-like headset.