Sun Archive 3/80 Tuning Page
Upgrading Sun 3/80 CPU boards to required revision for v3.0.3 monitor ROM
The starting point was three 501-1401 Sun 3/80 CPU boards, an 07rev50,
an 08rev50 (both initially with version 2.9.2 monitor ROM), and a 12rev50
(initially with version 3.0.3 monitor ROM). Trying the version 3.0.3
monitor ROM in either the 07rev50 or 08rev50 boards produced I/O mapper
write/write/read errors observed by connecting a terminal to serial port
A (the self test error could be aborted on the tty). A version 2.9.2
monitor ROM in the 12rev50 worked OK. I noted any differences in the
PCBs, wire links, component revision levels etc. in order to upgrade the
08rev50 to 12rev50 suitable for 3.0.3 ROM.
The Sun 3/80 version 3.0.3 monitor ROM offers: use of 4M memory SIMMs,
booting from CD-ROM using sr() device (not known if this works), and
it is the final 3/80 monitor version (so presumably has the least bugs!).
All three boards appear to have the same component revision levels (the PAL
devices for example have the last two digits of the Sun part number matching
between board, e.g. U0306 is a PAL16L8 with Sun part number of 3213101 for
all boards).
The 08rev50 and 12rev50 seem to have the same bare PCB revision level,
probably incorporating the modifications of the 07rev50 board consisting
of a number of thick wires direct from the underside of the power socket
to the underside of the SIMM sockets.
The only observed difference between the three boards was a number of wire
links, these changes are noted below.
07rev50 to 08rev50
Wire link from U0103 pin 5 (74AS02) to U0201 pin G1 (MC68882).
08rev50 to 12rev50
- Bend out U0308 (74AS00) pins 9 and 10 from PCB.
- Wire link from U0306 pin 18 (PAL16L8 3213101) to U0308 pin 9.
- Wire link from U1400 pin 56 (Emulex SCSI chip) to U0308 pin 10.
Warnings
- Make notes of what you do as you are going along, so if the conversion
doesn't work, or you get problems, you can get back to the original state.
- Only 501-1401 board covered. No idea about 501-1650 board.
- The only conversion tried was from 08rev50 or 12rev50, 07rev50 information
is included for interest only
- I have tried 4M memory SIMMs in my modified board. All sixteen slots were
filled to get 64M RAM (!). The 3/80 seemed to be OK - no errors from the
monitor ROM, SunOS booted, no unexplained crashes and sundiag didn't
complain when a memory test was run. The Sun hardware FAQ mentions 40M
being the maximum RAM in a 3/80 - why??
- Components are surface mount - be careful!
- I only tried versions 2.9.2 and 3.0.3 of the 3/80 monitor in the '12rev50'
upgrade. This was the final version Sun produced for the 3/80.
Chris Powell - 12th July, 1995. Updated 7th February, 1996.