Subject: Re: Quadra memory check
To: Tony Mantler <nicoya@apia.dhs.org>
From: David A. Gatwood <dgatwood@deepspace.mklinux.org>
List: port-mac68k
Date: 07/30/2000 22:03:37
On Sun, 30 Jul 2000, Tony Mantler wrote:

> At 11:24 PM -0500 7/30/2000, David A. Gatwood wrote:
> >On Sun, 30 Jul 2000, Tony Mantler wrote:
> [...]
> >> IIRC the F108 should
> >> cascade through a slot interrupt on VIA2 (slot E I think, but I could =
be
> >
> >Via2 Port B, slot F as far as I can tell.  Slot E is the PDS slot.  Slot
> >interrupts then cascade into Bit 1 on Via2 IFR.
>=20
> Ohyeah, forgot the PDS slot is on E.
>=20
>=20
> >> wrong), meaning that if you miss ANY slot interrupt, they'll ALL be go=
ne
> >> forever.
> >
> >That's the thing, though.  We never get any slot interrupts -- not even
> >the first one.  They never make it to VIA2 IFR.  VIA2 reads 0x00 at ever=
y
> >interrupt, indicating that nothing is ever reaching it.  I don't believe
> >it's even reaching VIA2 portB, either, sicne I see to recall that never
> >changing values.
>=20
> Make sure VIA2 portB is *absolutely empty* when the interrupts dissapear
> (or never appear in the first place) or you've found your problem. To
> narrow things down, I'd reccomend ripping out any Comslot or PDS cards, a=
nd
> making sure the video interrupts are switched off (Valkyrie, right? I thi=
nk
> that one's fairly well understood how to switch off).

Oh, one more thing: by empty, is that all 0's or all 1's?  On the PowerMac
x100's, for example, the slot interrupts are inversed from everything
else, but I can't tell if that's the case in the earlier VIAs or not.


> Yes, it's read only. The magic mojo to reset it is pretty much going arou=
nd
> to every possible device that could ever be connected via a slot interrup=
t
> and telling them "shut up, I'm trying to get some interrupts here" in an
> individually device-specific and entirely obsfucated and undocumented
> manner.

Blech.  Well, that's going to be nasty, since I depend on one of those
cards to get kernels to the thing....


> As you might be able to tell by now, slot interrupts really suck very lar=
ge
> interstellar rocks. Soon you too will learn to hate Jean Louise Gasse=E9 =
for
> making the Mac II so damn stupid, and everyone after for dragging the
> architecture forward so long. And people wonder why I don't want to buy a
> Be.

Heheh.


David

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