[jan-jaap]

My question is:This brick type is bootable with os irix in single mode?
Without daughterboard ps/2 Key/Mouse and other 3x serial port on rear panel?

The keyboard/mouse ports are not usable if you don't have graphics (Onyx 350).

My Origin 350 also only has a single console port and it runs fine. If you scroll down that page you can see some pics of the back side.

My system (2 modules) was port of a larger 32CPU config so it's possible one or more bricks of the original system had the extra serial ports.