The Mainframe Armory is the cities collection of stored weapons resources, located inside the Principal Office. It has an extensive arsenal of military supplies including ammunition and other military equipment. While vast, it is nowhere near as extensive as the Super Computer where one can access almost any specific command on the known Net. It has a huge blast door protecting its contents inside. Only system administrator Phong and authorized personnel such as Bob and Dot are allowed in here via the touch-screen interface panel.
This room was accessed when Hexadecimal unleashed the Medusa Bug on Mainframe. Bob sought Phong's help, but the old sprite showed that Mainframe only had a primitive Viral Erase Command to offer. Bob was for the most part, frustrated with the primitive weapons available. None of the tools were as advanced or sophisticated as those found in the Super Computer. In comparison, Mainframe's stockpile was obsolete and outdated, completely ineffective against self-replicating viruses or bugs. Phong has to constantly remind the Guardian that this is not the Super Computer. (The Medusa Bug)
A year latter, Megabyte convinced Hexadecimal to use her power to fake an upgrade, allowing him to infect Mainframe's Core Control Chamber. While Bob hastens to the Read Only Room to recharge Glitch, Dot wanders into the Armory to see what equipment it had to offer. She found an Exoskeleton Suit inside, and later used it to fight the power-hungry virus. (Infected)
When Megabyte and Hexadecimal became the deadly energy-absorbing Gigabyte, Bob's body armor took serious damage so he asked Phong for assistance. The old sprite reminded him this was not the Super Computer, but provided him with a better-protecting black suit of armor nonetheless. (Gigabyte)
The Armory room was invaluable when the Web invades Mainframe during the Web War. Dot and Mouse prepared themselves for battle while the hacker discusses from past experiences, how perilous working with viruses is. Dot soon emerges with a huge Plasma Launcher weapon, just for insurance. (Web World Wars)