MIPS RISComputer 3240
miod > machineroom > manufacturers > MIPS > RISComputer RC3240


This machine had been used to serve Minitel content, until decommissioned. At some point, it was spotted and salvaged by Marc Jacob, who was perfectly aware of the value (from a collector's point of view) of this machine; without enough spare time to tinker with it, he eventually sold it to me.


This machine is a deskside system, with small feet. The case is quite tall, because there is room for four full-length ISA devices, as well as six ISA form factor memory boards.
On the back of the machine are the various connectors: four DB25 serial ports, one 10base5 (AUI) Ethernet connector, and a Centronics SCSI external connector (here shown with a terminator plugged in).
Unlike the Magnum case, this system looks well-engineered and well built, despite the case screws being unexpectedly small.
This first-time impression is confirmed upon opening the machine. Three screws (only two in the picture, as one screw had been lost in the past) need to be removed, and then one side slides towards the back to expose the bowels of the system.
Nothing surprising here. The motherboard spans almost all the space within the case, except for the bottom which is used by the power supply. Four boards are plugged into it: the processor board at the bottom, over the empty (black) ISA slots, and three memory boards in the topmost (white) memory slots. The upper-right corner of the motherboard is covered by the internal devices enclosure: a tape drive at the top, and a full-height 5"1/4 hard disk in a vertical position underneath (a 650MB CDC 94191-15).
Here is what the processor board looks like. Nothing fancy, it sports an R3000 CPU, an R3010 FPU, 2x64KB L1 cache and the 50MHz clock which, being divided by two, runs the processor at a whooping 25MHz.
The processor board identifies itself as a M/180 processor board. This is a relic of the early M/xxx names of the first Mips computers. The 180 in the name is supposed to mean that this machine has a speed of 18.0 MIPS. That remains to be confirmed...
This is what the memory boards (8MB each) look like.
Here is what the uncluttered motherboard looks like, on the component side. The main power supply connectors are left screwed to the motherboard. The white six-port power connector near the center of the motherboard is apparently only used to power the hard drive and tape drive.
Looking carefully at the chips on the motherboard, the astute reader may spot: I have no idea what the white connector, next to the EEPROM, is; I would not be surprised if this turned out to be a VME expansion connector, allowing a 3U VME card cage to be connected (thus limiting VME support to A24/D16).
The other side of the motherboard is tame, but look out for blue straps!
A quick look at the power supply. It comes with its own test report summary printed and taped to its enclosure!

Patience is a virtue

Time to switch the machine on! And then... nothing happens. The fans blow, the disk spins up, but nothing appears on the console.
If you open the case, you'll notice a set of 8 diagnostic leds next to the white VME-like connector. These leds will lit during the self-tests, just like a Sun system of the '80s would do. Eventually, at the end of the self-tests, the system will greet you on the serial port, and the leds will display a moving pattern. Be warned that the selftests take about three minutes to complete! This is even worse than the Magnum. But it eventually outputs:
RC3240 MIPS Monitor Version 5.10 MIPS OPT Tue Nov 28 21:06:25 PST 1989 root
Memory size: 25165824 (0x1800000) bytes, 24 MB
Icache size: 65536 (0x10000) bytes
Dcache size: 65536 (0x10000) bytes
Notice the 64KB caches, twice larger than on the Magnum.
No surprise, there is still no way to figure out the Ethernet address of the on-board interface:
>> help
        autoboot:       auto
        boot:           boot [-f FILE] [-n] [ARGS]
        cat:            cat FILE_LIST
        disable:        disable CONSOLE_DEVICE
        dump:           dump [-(b|h|w)] [-(o|d|u|x|c|B)] RANGE
        enable:         enable CONSOLE_DEVICE
        fill:           fill [-(b|h|w)] [-v VAL] RANGE
        get:            g [-(b|h|w)] ADDRESS
        go:             go [INITIAL_PC]
        help:           help [COMMAND]
        help:           ? [COMMAND]
        initialize:     init
        load:           load CHAR_DEVICE
        put:            p [-(b|h|w)] ADDRESS VALUE
        printenv:       printenv [ENV_VAR_LIST]
        setenv:         setenv ENV_VAR STRING
        sload:          sload [-b] CHAR_DEVICE
        spin:           spin [-i CNT] [[-v VAL] [-c CNT] [-(r|w)(b|h|w) ADDR]]*
        unsetenv:       unsetenv ENV_VAR
        warm:           warm
        pr_tod:         pr_tod
        init_tod:       init_tod [SECS]

        commands that reference memory take widths of:
                -b -- byte, -h -- halfword, -w -- word (default)
        RANGE's are specified as one of:
Erase single characters by CTRL-H or DEL
Rubout entire line by CTRL-U
>> printenv
To be continued...

Some links of interest...