On 8/30/05, asbesto <asbesto@freaknet.org> wrote:

Hi,

is anyone here that can help us booting the pdp11/34 ? :

the boot loader hangs at 001012. can someone help understand
why?

we haven't any bus error, and we have no prompt at serial
terminal pressing "ctrl-boot"

this is the boot code, found in "E-10 Loading Software Bootstrap":

location        contents   pseudo-source code
001000          012701    mov #174400, r1
001002          174400
001004          012761   mov #13, 4(r1)
001006          000013
001010          000004
001012          012711   mov #4, @r1
001014          000004
001016          105711   tstb @r1
001020          100376   bpl .-2
001022          005061   clr 2(r1)
001024          000002
001026          005061   clr 4(r1)
001030          000004
001032          012761   mov #-400, 6(r1)
001034          177400
001036          000006
001040          012711 mov #14, @r1
001042          000014
001044          105711   tstb @r1
001046          100376   bpl .-2
001050          005007   clr pc

starting it, the display show "1012", i think this mean that
he stop at address 001012. why?

The display shows the next address to be executed. When the processor halts, what are the
actual contents of locations 1000-1010? Are they what you keyed in, or has this memory been
over-written?

This looks like code for a RL01/RL02.
Is the bus address of its control registers the normal 174400 - 177406?

If you replace the last instruction CLR PC (5007) with HLT (0000) does the processor
get there? This should happen regardless of what is read from the disk, because the
code from the disk is not executed.

You can find a lot of small key-in test programs at
< http://www.dunnington.u-net.com/public/ODT/SourceCode/ >

carl