From mboxrd@z Thu Jan 1 00:00:00 1970 Mime-Version: 1.0 Message-Id: In-Reply-To: <20031106070716.GB17235@pants.nu> References: <1067842481.17970.8.camel@gaston> <1067937269.680.92.camel@gaston> <1067985081.707.124.camel@gaston> <1068000383.692.132.camel@gaston> <1068016722.12704.148.camel@gaston> <20031106070716.GB17235@pants.nu> Date: Thu, 6 Nov 2003 10:44:44 -0600 To: linuxppc-dev list From: Jeff Walther Subject: Re: IRQS on 6 Slot Macs Content-Type: text/plain; charset="us-ascii" ; format="flowed" Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: At 23:07 -0800 11/05/2003, Brad Boyer wrote: >I just looked, and the Quadra 840AV has a chip on the motherboard with >an AMD logo and the part number AM79C950KC. And as a noteworthy fact, >the AV models were the only 68k models to have a number of features, >including using the MACE ethernet and having DMA on the serial ports. >All the other 68k Macs with onboard Ethernet use the sonic driver. >Supposedly the AV models also had an AMD chip controlling the floppy >drive, but this is the only AMD labelled chip. Perhaps it has more >features than SCSI, Ethernet, and serial? There are several very >large Apple ASICs, tho... Thank you. So CURIO goes all the way back to the AV Quadras. I thought I had read that but wasn't certain. I know it doesn't go any further back because I have examples of the Q650/800 and Q700 boards handy and they definitely don't use it. According to Apple's Developer Note for the AV Quadras, "Centris_660AV_Quadra_840AV.pdf" the floppy controller is a separate chip called "New Age". I would expect it to be relatively small, probably 40 or 44 pins in a PLCC package, but that's a guess based on Apple's other floppy controllers. I think CURIO is limited to the three features listed. The SWIM is a separate chip in the x100 Macs, but I think it's integrated into GC in the x500 Macs. Let's see, from "PPC_9500.pdf": "The Grand Central IC performs the following functions: support for the Cuda IC (the VIA registers) central system interrupt collection support for descriptor-based DMA for I/O devices floppy disk interface (SWIM III) "The Grand Central IC contains a DMA controller. It provides DBDMA support for all I/O transfers, including transfers through its internal I/O controllers as well as transfers through the Curio IC for other I/O devices." Jeff Walther ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/