User manuals:
SGI Machines
Indigo (IP20)
Indy (IP24)
Octane (IP30)
O2 (IP32)
Hardware (programming) documentation for SGI machines
SGI Indigo/Indigo2/Indy
dmux1.pdf -- Data path between processor, memory, and GIO bus
gio64.pdf -- GIO bus specification
hpc3.pdf -- High-performance Peripheral Controller (HPC3) specification
ioc.pdf -- I/O Controller (IOC) specification
mc.pdf -- Memory Controller (MC) specification
rb2.pdf -- RAM Buffer (RB2) specification
rex3.pdf -- Raster Engine (REX3) specification
ro1.pdf -- ReOrganizer (RO1) specification
vc2.pdf -- Video Controller (VC2) specification
vino.pdf -- Video (VINO) specification
vino.01.pdf -- Timing Diagram for VINO (1)
vino.02.pdf -- Timing Diagram for VINO (2)
vino.03.pdf -- Timing Diagram for VINO (3)
vino.04.pdf -- Timing Diagram for VINO (4)
vino.05.pdf -- Timing Diagram for VINO (5)
vino.06.pdf -- Timing Diagram for VINO (6)
xmap9.pdf -- XMAP9 specification
SGI O2
ad1845.pdf -- Analog Devices AD1845 specification (audio)
ds17287.pdf -- Dallas Semiconductors DS17287 specification (RTC/NVRAM)
DP83840.pdf -- National Semiconductor DP83840A specification (MII)
nec_vr5000.pdf -- NEC VR5000 specification (CPU)
PC16550D.pdf -- National Semiconductor PC16550D specification (serial)