Andreas Freiherr wrote:
>
> Ben,
>
> let me continue to be picky, as I often learn new things by trying to
> really and thoroughly understand how something works. ;-)
This example was made as a general example not a real machine.
> Will work for some, but not all, media. RL01/RL02, for example, can be
> done this way. I have seen a four-word bootstrap that indeed only
> consists of putting the required command into the CSR and then WAITing.
> Operating instructions: "let the program run for a few seconds, then
> HALT and restart at address zero."
The front panel is your friend.:)
>
> Will the IRQ really clear the halt F/F, causing the processor to resume
> running? - I need to get my machines running soon, memory is fading...
While this was not a real example, often a bootstrap I suspect could use
of
tricks with the hardware after reset.
> Other disk types, such as the RXs, require loading of more than one
> sector, and not many controllers are like the RK11 in that they
> automatically increment sector counters.
But did not the big disc controllers have front panel as well?
I always used paper tape on a PDP-8 with a front panel.
> What I wanted to point out is that you need to have some kind of
> "handler" for the reset button if you want your PDP-11 to have a life
> after that. I might call this "handler" a "bootstrap" :-) - And I
> intended to have a PDP-11 processor execute the instructions, not a
> human! ;-)
One other factor with device drivers like on the PDP-8 they had to be
small and support swapping all of core to and from disk.
> --
> Andreas Freiherr
> Vishay Semiconductor GmbH, Heilbronn, Germany
> http://www.vishay.com
--
Ben Franchuk - Dawn * 12/24 bit cpu *
www.jetnet.ab.ca/users/bfranchuk/index.html
Received on Thu Feb 28 2002 - 16:10:22 GMT