[jan-jaap]

By popular demand: the GM monitor

Upon power-on it spits this out. Takes only a fraction of a second:

Code:

PASS: GM UART okay; about to test the first location in DRAM.
PASS: GM DRAM okay; about to initialize DRAM global variables.

Loading PP ucode Version:  @(#) PEAPOD 1.2 pp microcode assembler - 6/20/87
Wed Dec  9 16:59:30 1987 user unknown revision(1.74)

PASS: PP SRAM okay.
PASS: GM SRAM Word Count register okay.
PROM diags completed.

Prom revision Thu Jan 14 17:09:34 PST 1988.

Clearing power-on Host interrupt (level 6).

Clearing power-on Retrace interrupt (level 5).

Clearing power-on Fifo interrupt (level 4).

Clearing power-on PP interrupt (level 2).

gm>

Let's get some help:

Code:

gm>  ?
        GM monitor commands (default for optional size {b|w|l} is word)

b{s|d|q} [addr]         Set, delete, or query breakpoints.

c       Continue a program at the current pc.

d{b|w|l} [addr1][addr2][count]
        Dumps memory by bytes, words, or longs, from addr1 to addr2;
        the dump may be repeated count times.

e{b|w|l} [address][actions]
        Queries and/or sets memory beginning at the given address,
        in byte, word, or long format.

f{b|w|l} [addr1][addr2][data][increment][count]
        Fills memory as bytes, words, or longs, from addr1 to addr2,
        using data as the fill value, optionally incremented by increment;
        the fill may be repeated count times.

g [address][arguments]
        Go: program execution will begin at address (if given) or at the
        current pc: arguments (if given) will be passed to the program.

Type <cr> to continue, <q> to return to the monitor: 

h       This help message is printed.

q       Quit: Forces a hard reset.

r       Dumps 68020 processor registers (data, address, pc, sr).

s       Single-step the suspended program.

t [test mask][addr1][addr2][count]
        Tests memory from addr1 to addr2;
        the tests may be repeated count times.  The possible tests are:

        Mask bit 0 - All 0 Test
        Mask bit 1 - All 1 Test
        Mask bit 2 - Alternate All 0/All 1
        Mask bit 3 - Alternate 55555555/AAAAAAAA
        Mask bit 4 - Forward Address Test
        Mask bit 5 - Backwards Address Test
        Mask bit 6 - Marching Ones Test
        Mask bit 7 - Marching Zeros Test

Type <cr> to continue, <q> to return to the monitor: 

u       A suspended program's stack is unwound and printed out.

z[addr] Disassemble memory, starting at the specified address.

gm>

I tried 'q' which resets the GM and 'r' which dumps some hex numbers. Lacking any other documentation, this isn't going anywhere.
Oh, the memory test works:

Code:

gm> t ff
Defaulting to infinite DRAM test.
Testing memory from 0x9803F000 to 0x980FEFFC
01234567
PASS: memory test mask 0xFF (pass 1)
01234567
PASS: memory test mask 0xFF (pass 2)
01234567
PASS: memory test mask 0xFF (pass 3)
01234567
PASS: memory test mask 0xFF (pass 4)
01234567
(... etc ...)

---

The host side. I started it with the keyboard, mouse disconnected in order to force console on serial and avoid a crash on bootup. Then start X11 manually (IRIX 4.0.5). This causes the crash:

Code:

IRIS 3# /usr/gfx/startgfx
Sent SIGHUP to xdm
IRIS 4# Bus Error: Parity Error Bits: 0x0:  physaddr:0x1DF0000C

PANIC: KERNEL FAULT
PC: 0x8001FD1C ep:800FE198
EXC code:28, `Data Bus Error '
Bad addr: 0x10019000, cause: 0x3000041C<CE1,CE0,IP3>
sr: 0xF804<IM7,IM6,IM5,IM4,IM3,IEp>


dumping to dev 0x1621 at block 48798, numpages 4095
................................................................
dump completed

This was with the 12 MHz IP4 board installed (4D/70):

Code:

1 12 MHZ IP4 Processor
FPU: MIPS R2010 VLSI Floating Point Chip Revision: 2.0
CPU: MIPS R2000 Processor Chip Revision: 5.0
On-board serial ports: 4
Data cache size: 32 Kbytes
Instruction cache size: 64 Kbytes
Main memory size: 16 Mbytes
ENP-10 Ethernet controller: enp0, firmware version 4 (SGI)
GT Graphics option installed
Disk drive: unit 1 on SCSI controller 0
Integral SCSI controller 0: Version WD33C93

Interestingly, the GM1 monitor output lists "Dec '87 / Jan '88" as creation date, which suggests that my IP4 PROM (from Dec '88) should work.

I wonder what's going on here. I'll double check the backplane VME jumpers, but the boards are installed as documented in the Hardware Developer's Handbook: (1) IP4, (2) ENET, (8) GE, (9) GM, (10) RM, (11) RV, (12) RM. There's nothing like missing bulkhead covers or unused cables to suggest that more cards were installed at some point.