Article 51571 of comp.sys.dec: In article <3373890D.41C6@eng.pko.dec.com>, Kenny House wrote: > > Jack -- > > Here is my explanation of the DIGITAL Personal Workstation > a-Series (Miata) and au-Series (MX5) PCI slot restrictions. The > Console operation described below is the same for AlphaBIOS and > SRM. > > First, let's define some terms. PCI slots four and five (at the > bottom of the enclosure) are on the primary bus; slots one, two > and three are on the secondary bus (behind a PCI-to-PCI bridge). > > The Consoles use VGA legacy mode accesses to control the graphics > display. Some graphics devices use addresses that are not > strictly legacy-compatible, blindly (and falsely) assuming that > these are passed through the PCI-to-PCI bridge to the secondary > PCI bus. Some graphics cards don't work correctly in VGA legacy > mode, at least not behind a PCI-to-PCI bridge. These graphics > cards must be on the primary PCI bus (in slots four or five). VGA > legacy addresses are ISA memory addresses A0000h to BFFFFh and ISA > I/O addresses 3B0h to 3BBh and 3C0h to 3DFh. > > Some graphics cards appear to do ISA legacy operation just fine > behind a bridge (in slots one, two or three). Due to differences > in the Console drivers, there may be some cards which work for > AlphaBIOS and not for SRM, or vice versa. I'll ask the > Console development groups to try to get the greatest coverage in > this area. > > There is an interaction between some PCI devices and the Pyxis > host bridge which can cause data errors in some circumstances. > These circumstances are avoided when the device is isolated from > the host bridge by a PCI-to-PCI bridge, i.e., when the device is > placed in slots one, two or three. To ensure data integrity, the > Console checks that the vendor/device IDs of devices on the > primary bus are in a table of known good devices; if the device > is not in this table, then the Console displays an error message > and refuses to boot the operating system (the SRM Console may > display the error message to the serial console device, so it may > not show on your graphics screen). This is the additional > restriction on devices in slots four and five. > > Our Qualification Engineering group performs extensive tests on > all options which we sell, either directly or by reference. If a > device passes qualification for operation on the primary bus, then > we request that the vendor/device ID is added to the Consoles' > table at the next release of the firmware. If we allow a device > in those slots, then we know it will work. If a device is not in > the table, causing your system not to boot, it may be due to one > of the following reasons: > > 1) the device failed qualification, > 2) the device passed qual and you don't have the latest > firmware, > 3) the device passed qual and the next version of firmware > hasn't been released yet, > 4) we haven't finished testing the device yet, or > 5) we don't plan on testing the device. > > It is quite expensive to do the thorough testing required by > DIGITAL, and our Qual group doesn't have sufficient resources to > test every card in the world. If you have an option that you > would like DIGITAL to offer, please have your salesperson, > distributor or value-added reseller send a request to Workstations > Product Management. > > -- Kenny > ------------------------------------------------------------------------------ > Kenneth A. House house@eng.pko.dec.com > Digital Equipment Corporation > 129 Parker Street - PKO3-2/T25 My opinions are not necessarily > Maynard MA 01754 USA shared by Digital Equipment Corporation > > > I have a Digital Personal Workstation 433a and an unsupported > > graphics card, the Dynamic Pictures Oxygen 202. It seems that > > the firmware, whether it's AlphaBIOS or Digital UNIX console, > > is not happy with the graphics board. The Matrox Millenium, > > a supported device, works much better. > > > > > Possible explanations: > > > > 1. Digital's firmwares are programmed to use only supported > > devices in slots 4 and 5. > > kah> Yes, that way we know they'll work. > > > 2. Digital UNIX console only looks for display devices in > > slots 4 and 5. > > kah> No; some display devices don't work behind a bridge, at least > kah> not with SRM drivers. > > > Conclusion: > > > > Digital only wants owners of DPW to use the approved display devices. > > kah> DIGITAL only allows qualified components on the primary PCI bus, > kah> and some display devices don't work on the secondary bus. > > > Is it too much to wish for Digital to remove these restrictions in the > > firmware? > > kah> Let me see what I can do to get better support for graphics > kah> cards behind the bridge. Of course, no one around here listens > kah> to me, so don't hold your breath. If I had known that the firmware is so restrictive on what devices can be used, I would probably not have bought one. My gripe is that why not boot with unsupported display devices? If there are problems with compatibility between the device and the computer, have the device manufacturer work it out. Don't just refuse to boot up. Digital doesn't provide technical support for unqualified devices, so the extra cost of support for these devices is not a reason for the restrictions. So is there a rational reason for it? What about other vendors' Alpha machines? Do they have these restrictions? Can someone enlighten me? What about other Digital Alpha lines, or the not yet available 21164PC? My options are to exchange my unqualified Oxygen 202 for another graphics card that is or return the DPW for another computer that works with Oxygen 202. The problem with returning the hardware is that the 30-day money back guarantee has passed. It took a long time for me to find out this compatibility issue because it didn't surface until I wanted to upgrade the AlphaBIOS and found that I couldn't. The reason I couldn't is because the BIOS upgrade requires me to start SRM. Since my display device is unsupported, under SRM it doesn't display anything. I don't want to perform an upgrade blind! I'd very much like to see that the restrictions on the display devices be removed. Perhaps the firmware can instead perform basic tests on unsupported devices to ensure a certain degree of compatibility. Jack -------------------==== Posted via Deja News ====----------------------- http://www.dejanews.com/ Search, Read, Post to Usenet