Subject: Re: more on the 400-series utility chip
To: mike smith <firstname.lastname@example.org>
From: Herb Peyerl <email@example.com>
Date: 03/21/1997 06:35:04
mike smith <firstname.lastname@example.org> wrote:
> Jason Thorpe wrote:
> > We have the following items (offsets from util chip base)
> > 0x0080 calendar of some sort
> This one's a bit weird; have to keep looking at it.
I don't think you're terribly interested in that calendar 'cuz there's no
battery hooked up to it.
The "docs" that I have from the Apollo DN2500 (codenamed "frodo") and the
"utility chip" that it has indicate effectively what you guys are seeing
as far as layout.
sio0 base+0x0 keyboard/mouse
calendar base+0x80 calendar / RAM device (?)
cpu_isr base+0xc0 interrupt status reg
bit 7 PC/AT IO_CH_CK low = PC AT board asserted IO check
bit 6 unused
bit 5 53c90 scsi interrupt.
bit 4 53c90 DMA request.
bit 3 AT IRQ 12,none,14 or 15.
bit 2 AT IRQ 7,9,10,11
bit 1 AT IRQ 3,4,5,6
bit 0 normal/service switch. hi=normal, low=service.
cpu_ccr base+0xd0 cpu control reg
diag_cr base+0xd0 Diagnostic mode control register
bit 7 fpu enable
bit 6 toggle parity value when bit 5 is low
bit 5 force parity error
bit 4 clear parity error & buserr reg
bit 3 enable 4mbit drams, hi=1mbit, lo=4mbit
bit 2 disable parity error nmi.
bit 1 margin power supply low
bit 0 margin power supply high