Path: utzoo!attcan!uunet!pyrdc!grebyn!ckp
From: ckp@grebyn.com (Checkpoint Technologies)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Motherboard revision differences
Message-ID: <20194@grebyn.com>
Date: 29 Jun 90 15:42:33 GMT
References: <4060@uqcspe.cs.uq.oz.au> <12955@cbmvax.commodore.com> <[2688b902:593.2]comp.sys.amiga.hardware;1@wcbcs> <8439@uhccux.uhcc.Hawaii.Edu>
Reply-To: ckp@grebyn.UUCP (Checkpoint Technologies)
Organization: Grebyn Timesharing, Vienna, VA, USA
Lines: 26

In article <8439@uhccux.uhcc.Hawaii.Edu> olson@donald.uhcc.Hawaii.Edu (Todd Olson) writes:
>	My 4.3 with a 1-meg Agnus works with my 2630..sorta.
>Upon guru the screen will go blank, no guru message, just a blank screen,
>when I then three finger salute, I  get the guru, then one more three
>finger salute to get back to working order.  This is a slight pain at
>times, but I can live with it unless there is a quick easy fix.

I see from this you're using SetCPU FASTROM.  The explanation for this
effect is that when you guru, the system performs a RESET operation,
which un-configures any auto-config devices or memory you have.  This
includes the RAM on-board the A2630 card.  But, when you use SetCPU
FASTROM, some of this RAM has been used to store a ROM image.  Now,
RESET doesn't affect any of the 68030's own state, meaning that the MMU
is still turned on and translating ROM addresses to that RAM area, but
now the RAM has disappeared.  So the CPU gets hung.  When you use the
three-finger reset, the MMU is then reset, the ROM image is properly
located, and the system proceeds.  It finds the GURU information and
reports it.

There is no fix for this, aside from not using FASTROM.

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