Hoorah!!

I have finally found the bit in RAM on my LCIII which handles interrupts
from the video cards.

It appears that the ones that have been hosing my system are simply
vertical retrace interrupts.  If I am correct in my understanding of the
situation, macs have two sorts of vertical retrace interupts, potentially.
'Fake' 60Hz interrupts used for timing, and genuine ones from the video
card which can potentially be used to reduce screen flicker.  Since these
are 'genuine' ones, I can ignore them (although whoever does us a color
X-server might conceviably want to handle them).

The upshot of all this is that I have found the chunk of code which says
"OK video card, thank you very much, I know about that now, so you can
unflag that interrupt please".  And I have just applied it...

It is a little hard for me to tell if this magically makes ethernet work,
since my ethernet cables are once more at work, but I am not immediately
hopeful.  In any case, I am making progress.  Pinging an adress out on ae0
currently wedges the machine.  Utterly.  Beyond reach of an NMI.  Which is
a little painful...

Possibly my ethernet card is no supported after all... still, I will
investigate tomorrow, it being rather late here now.

As I am testing these kernels, I am seeing a recurrence of a problem I have
seen (and reported) before, but never quite understood.  Apparently
non-deterministically, my machine (an LCIII with FPU and 12" monitor) will
hang immediately after the grf0 attachment line is printed.  I don't think
this has anything to do with my new via code, since it happens before via
interrupts are enabled, and it has always happened occasionally.  Mind you,
just sfter grf0 attachment = just before ae0, so the ethernet card might be
connected.  Hitting any key throws a kernel illegal instruction.  Has
anyone else seen this?

Good night to you all,

Jules

PS Why do we build the fpsp when we don't have a single working 040 port -
it seems like a bit of a waste of CPU ;-) ?


/----------------+-------------------------------+---------------------\
|  Jelibean aka  | jules@mailbox.co.uk           |  6 Evelyn Road      |
|  Jules aka     |                               |  Richmond, Surrey   |
|  Julian Bean   |(jelibean@jmlbhome.demon.co.uk)|  TW9 2TF    *UK*    |
+----------------+-------------------------------+---------------------+
|  The Other Place - n. (pop.) Depending on the affiliation of the     |
|  speaker, one of Oxford, Cambridge, The House of Lords, The House of |
|  Commons, Hell.  Draw your own conclusions.                          |
\----------------------------------------------------------------------/