The main machine in the line was the GE-225 (1961). It used a 20-bit word, of which 13 bits could be used for an address. Along with the basic CPU the system could also include a floating-point unit (the "Auxiliary Arithmetic Unit"), or a fixed-point decimal option with three six-bit decimal digits per word. It had 11 I/O channel controllers, and GE sold a variety of add-ons including disks, printers and other devices. The machines were built using discrete transistors, with a typical machine including about 10,000 transistors and 20,000 diodes. They used core memory, and a standard 8 system held 186,000 magnetic cores. They weighed about .