Run Forest, run!

After having figured out the basics, it was time to prove the concept. First, I needed a (simple) program to run on the NumberSmasher. Here it is, reeeeally simple. It’s just an excerpt of the original 77 assembly lines. If you’re interested in the whole thing, it’s here.

The main-loop is just this. Read a byte from the C012 link, add 1 to it and write it back to the C012:

mov    iobase, %r4

  call    getlink        # (watch following delay slot!)
   shl    %r0, %r4, %r16    # mov r4, r16 - save base address

  addu    1, %r16, %r17    # add 1 and move into r17

  call    putlink        # (watch following delay slot!)
   shl    %r0, %r4, %r16    # mov r4, r16 - save base address

  br        loop

What a task for a “Cray on a chip”! 😉 Ok, putting this into the assembler (currently gnu-as on Linux), linking and finally making it a pure binary with ‘objcopy -O binary hb_test.cof hb_test.bin‘ I got this binary.

How do I get it into the NumberSmasher? Again, that required a bit of coding… say Hi to nc_load.exe.
This little tool loads a pure i860-binary, pokes it into the NumberSmashers RAM and optionally starts it afterwards, ie. ‘nc_load hb_test.bin 20 start‘ loads my test program to address 0x14 and starts it from there.
[Having read the previous post, you should know that you could omit the ‘start’ parameter and just poke 20 to address 0 to start the code]

Test, test, one, two, three…

And now the exciting part: Does it work? The easiest way to test this is good ol’ debug again:

C:\> debug
-o 151 41
-i 150

Yay! If this isn’t proving the sense of life, what else!?!? 😉 Ok, what happened here is simple. I wrote 41 to port 151 on which the C012 is listening for input, then I read from port 150 which is the result of adding 1 to the input. Quod erat demonstandum. Program is running successfully!

Be aware that after starting a programm, the NumberSmasher is continously running that code, i.e. peek & poke do not work anymore because the Boot-ROM is out of the game.
You have to reset the NC which is done in classic INMOS-style, i.e. sending a zero to port 0x160. Thats ‘-o 160 0’ in debug. NB: Resetting the NC does not clear its RAM. The previously uploaded program is still available and can be re-started by pokeing the start-address to 0.

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