Motorola 68230 - Vanguard 300 DSU/CSU Operator's Manual page 13

Vanguard 305:
Token Ring
Memory
Two Mbytes of FLASH memory and four Mbytes of DRAM reside on the
motherboard. An optional SIMM can be used to expand DRAM to 8 Mbytes.
Support Token
includes: Ring
STP
UTP
Either one of
the interfaces
can be
connected and
operated, but
not
simultaneously.
4 or 16 N/A
Mbps
(Default is 4
Mbps)