		FreeBSD/alpha Hardware Information
		==================================

This file is maintained by Wilko Bulte <wilko@freebsd.org>

Additions, corrections and constructive criticism are invited. In 
particular information on system quirks is more than welcome. 


Overview
--------

This document tries to provide a starting point for those who want to start
running FreeBSD on an Alpha-based machine. It is aimed at providing
background information on the various hardware designs. It is not a
replacement for the systems manuals. 

The information is structured as follows:

- general hardware requirements to run FreeBSD on Alpha.
- system specific information for each of the systems/boards supported
  by FreeBSD/alpha.
- information on expansion boards for FreeBSD/alpha, including things
  that differ from what is in the generic supported hardware list.


In general, what do you need to run FreeBSD/alpha? 
--------------------------------------------------

Obviously you will need an Alpha machine that FreeBSD/alpha knows about.
Alpha machines are NOT like PCs. There are considerable differences
between the various chip sets and mainboard designs. This means that a kernel
needs to know the intimate details of a particular machine before it can run
on it. Throwing some odd GENERIC kernel at unknown hardware is almost
guaranteed to fail miserably.

For a machine even to be considered for FreeBSD use please make sure it has
the SRM console firmware installed. Or at least make sure that SRM console 
firmware is available for this particular model. If FreeBSD does not
currently support your machine type, there is a good chance that this will
change some time, assuming there is a SRM available.

Machines with the ARC/AlphaBIOS console firmware are intended for 
WindowsNT. Some of them have SRM firmware available in the system ROMs 
which you only have to select (via an ARC/AlphaBIOS menu). In other cases 
you will have to re-flash the ROMs with SRM code. Check on
http://ftp.digital.com/pub/DEC/Alpha/firmware to see what is available
for your particular system. In any case: no SRM -> no FreeBSD (or NetBSD, 
OpenBSD, Tru64 Unix or OpenVMS for that matter). With the demise of
WindowsNT/alpha a lot of former NT boxes are sold on the second hand
market. They have little or no trade-in value when they are NT-only from the
console perspective. So, be suspicious if the price appears too good.
Known non-SRM machines are:
	Digital XL series
	Digital XLT series
	Samsung PC164UX
	Samsung 164B

To complicate things a bit further: Digital used to have so called
'white-box' Alpha machines destined as NT-only and 'blue-box' Alpha machines
destined for OpenVMS and Digital Unix. These names are based on the color
of the cabinets, 'frostwhite' and 'topgunblue' respectively.
Although you could put the SRM console on the whitebox, OpenVMS and Digital
Unix will refuse to boot on them. FreeBSD in post-4.0R will run on both the
white and the blue-box variants. Before someone asks: the white ones had a
rather different pricetag.

As part of the SRM you will get the so called OSF/1 PAL code (OSF/1 being the
initial name of DECs Unix offering on Alpha). The PAL code can be thought
of as a software abstraction layer between the hardware and the operating
system. It uses normal CPU instruction plus a handful of privileged
instructions specific for PAL use. PAL is not microcode by the way. 
The ARC firmware contains a different PAL code, geared towards WinNT and in
no way suitable for use by FreeBSD (or more generic: Unix or OpenVMS).
Before someone asks: Linux/alpha brings its own PAL code, allowing it to
boot. There are various reasons why this is not a very good idea in the
eyes of the *BSD folks. I don't want to go into details here.

There is another pitfall ahead: you will need a disk adapter that the SRM
console recognizes in order to be able to boot from your disk. What is 
acceptable to SRM as a boot adapter is unfortunately system / SRM version
dependent. For older PCI based machines this means you will need either 
a NCR/Symbios 53C810 based adapter, or a Qlogic 1020/1040 based adapter. 
Some machines come with a SCSI chip embedded on the
mainboard. Newer machine designs and SRM versions will be able to work with
later SCSI chips/adapters. Check out the machine specific info below.

The problem might bite those who have machines that started their lives as 
WinNT boxes. The ARC/AlphaBIOS knows about *other* adapter types that it 
can boot from than the SRM. For example you can boot from an Adaptec 2940UW 
with ARC but not with SRM. 

Some adapters that cannot be booted from work fine for data-only disks
(e.g. Adaptec 2940x boards). The differences between SRM and ARC could also
get you pre-packaged IDE CDROMs and hard drives in some (former NT) systems. 
SRM versions versions exist (depends on the mainboard) that can also boot 
from IDE disks. 

FreeBSD/alpha 4.0 and later can be booted from the distribution CDROM.
Earlier versions needed booting from a 2-floppy set.

If you don't have/want a local disk drive you can boot via the Ethernet.
This assumes a Ethernet adapter/chip that is recognized by the SRM.
Generally speaking this boils down to either a 21040 or 21142 or 21143 
based Ethernet interface. Older machines / SRM versions may not recognize
the 21142 / 21143 Fast Ethernet chips, you are limited to using 10Mbit
Ethernet for net booting those machines. Non-DEC cards based on said chips will
generally (but are not guaranteed to) work. Note that Intel took over the
21x4x chips when it bought Digital Semiconductor. So you might see an Intel
logo on them these days.

Alpha machines can be run with SRM on a graphics console or on
a serial console. ARC can be run on a serial consoles if need be. VT100
emulation with 8 bit controls should at least allow you to switch from 
ARC to SRM mode without having to install a graphics card first.

If you want to run your Alpha without a monitor/graphics card 
just don't connect a keyboard/mouse to the machine. Instead hook 
up a serial terminal[emulator] to serial port #1.  The SRM will 
talk 9600N81 to you. This can be really practical for debugging purposes.
Beware: some/most (?) SRMs will also present you with a console prompt at
serial port #2. The booting kernel, however, will display the boot messages
on serial port #1 and will also put the console there. This can be extremely
confusing.

Most PCI based Alphas can use ordinary PC-type VGA cards. The SRM contains
enough smarts to make that work. It does not, however, mean that each and
every PCI VGA card out on the street will work in an Alpha machine. Things
like S3 Trio64, Mach64, and Matrox Millenium generally work. Old ET4000 
based ISA cards have also worked for me. But ask around first before buying. 
Please note that TGA cards are not supported as FreeBSD console display cards. 

Most PCI devices from the PC-world will also work in FreeBSD/alpha PCI-based
machines. Check the /sys/alpha/conf/GENERIC file for the latest word on
this.

Parallel printer ports also work on FreeBSD/alpha.

For Alpha CPUs you will find multiple versions. The original Alpha
design is the 21064. It was produced in a chip process called MOS4,
chips made in this process are nicknamed EV4. Newer CPUs are 21164, 21264
etc. You will see designations like EV4S, EV45, EV5, EV56, EV6, EV67.
The EVs with double digit numbers are slightly improved versions. For example
EV45 has an improved FPU and 16 kByte onchip separate I & D caches compared
to the EV4 on which it is based. Rule of thumb: the higher the digit
immediately following 'EV' the more desirable (read: faster / more modern).

For memory you want at least 32 Mbytes. I have had FreeBSD/alpha run on a
16 Mbyte system but you will not like that. Kernel build times halved when
going to 32 Mbytes. Note that the SRM steals 2Mbyte from the total system 
memory (and keeps it). For more serious use >= 64Mbyte is recommended. 

While on the subject of memory: pay close attention to the type of memory
your machine uses. There are very different memory configurations and
requirements for the various machines.

Final word: I expect the above to sound a bit daunting to the first-time
Alpha user. Don't be daunted too much. And do feel free to ask questions.


System specific information
---------------------------

Below is an overview of the hardware that FreeBSD/alpha runs on.
This list will definitely grow, a look in /sys/alpha/conf/GENERIC
can be enlightening. Alpha machines are often best known by their project
code name, when known these are listed below in ().

*
* AXPpci33 ("NoName")
*
The NoName is a baby-AT mainboard based on the 21066 LCA (Low Cost Alpha)
processor. It was originally designed for OEM-use. The LCA chip includes
almost all of the logic to drive a PCI bus and the memory subsystem. 
All of this makes for a low-priced design. 

Due to the limited memory interface the system is not particularly
fast in case of cache misses. As long as you stay inside the on-chip cache
the CPU is comparable to a 21064 (first generation Alpha). These boards 
should be very cheap to obtain these days (even here in the Netherlands 
they were sold new for US$ 25).

Features:
- 21066 Alpha CPU at 166 MHz or 21066A CPU at 233MHz
  (21068 CPUs are also possible, but are even slower. Never seen/used one)
- memory bus: 64 bits 
- on-board Bcache / L2 cache: 0, 256k or 1 Mbyte (uses DIL chips)
- PS/2 mouse & keyboard port OR 5pin DIN keyboard (2 mainboard models)
- memory: PS/2 style 72 pin 36 bit Fast Page Mode SIMMs, 
	  70ns or better,
          installed in pairs of 2,
	  4 SIMM sockets
	  uses ECC 
- 512kB Flash ROM for the console code.
- 2x 16550A serial ports, 1x parallel port, floppy interface
- 1x embedded IDE interface
- expansion: 3 32 bit PCI slots (1 shared with ISA)
	     5 ISA slots (1 shared with PCI)
- embedded Fast SCSI using a NCR/Symbios 53C810 chip

SRM:
NoNames can either have SRM *or* ARC console firmware in their Flash ROM.
The Flash ROM is not big enough to hold both ARC and SRM at the same time 
and allow software selection of alternate console code. But you need 
SRM-only anyway.

Cache:
Cache for the NoNames are 15 or 20 ns DIL chips. For a 256 kByte cache you
want to check your junked 486 mainboard. Chips for a 1 Mbyte cache are a rarer
breed unfortunately. Getting at least a 256kByte cache is recommended
performance wise. Cache-less they are really slow.

Power:
The NoName mainboard has a PC/AT-standard power connector. It also has 
a power connector for 3.3 Volts. No need to rush out to get
a new power supply. The 3.3 Volts is only needed in case you run 3.3 Volts
PCI expansion boards.

IDE:
SRM cannot boot from IDE disks.

Memory:
Make sure you use true 36 bit SIMMs, and only FPM (Fast Page Mode). EDO RAM
or SIMMs with fake parity *will not work* (the board uses the 4 extra bits
for ECC!). 33 bit FPM SIMMs will for the same reason not work either. 

Keyboard/mouse:
Given the choice, get the PS/2-variant mainboard. Apart from giving you a
mouse port as bonus it is directly supported by Tru64 Unix in case you ever
want/need to run it. The "DIN-plug"-variant should work OK for FreeBSD.

The OEM manual is recommended reading. 
See ftp://ftp.digital.com/pub/DEC/axppci/design_guide.ps

The kernel configuration file for a NoName kernel must contain:
	options         DEC_AXPPCI_33           
	cpu		EV4


*
* Universal Desktop Box (UDB or "Multia")
*

Note: Multia can be either Intel or Alpha CPU based. We assume Alpha based
      ones here for obvious reasons.

Multia is a small desktop box intended as a sort of personal workstation.
They come in a considerable number of variations, check closely what you
get.

Features:
- 21066 Alpha CPU at 166 MHz or 21066A CPU at 233MHz
- memory bus: 64 bits 
- on-board Bcache / L2 cache: COAST-like 256 kByte cache module
			      233MHz models have 512kByte of cache
- PS/2 mouse & keyboard port
- memory: PS/2 style 72 pin 36 bit Fast Page Mode SIMMs, 
	  70ns or better,
          installed in pairs of 2,
	  4 SIMM sockets
	  uses ECC 
- 2x 16550A serial ports, 1x parallel port, floppy interface
- 1x embedded 21040 based 10Mbit Ethernet, AUI or 10base2 connector
- expansion: 1 32 bit PCI slot
- embedded Fast SCSI using a NCR/Symbios 53C810 chip on the PCI riser card

SRM/ARC:
Multia has enough Flash ROM to store both SRM and ARC code at the same time
and allow software selection of one of them.

Expansion:
Multia has only one 32 bit PCI slot for expansion, and it is only 
suitable for a small form factor PCI card too. In sacrificing the PCI slot
space you can mount a 3.5" hard disk drive. Mounting stuff may have come
with your Multia. There are also models that do have the riser card, but
lack the actual PCI connector.

CPU:
The CPU might or might not be socketed, check before considering CPU upgrade 
hacks. The low end Multia has a soldered-in CPU.

Graphics: 
It comes with a TGA based graphics on-board. Which is not suitable for
console use according to reports I have received. Which means you will
have to run it using a serial console.

Floppy:
Although the Multia SRM supports booting from floppy this is problematic. 
Typical errors look like "*** Soft Error - Error #10 - FDC: Data overrun or
underrun". The best available workaround to install FreeBSD is to boot from
CDROM.

Hot:
Multias are somewhat notorious for dying of heat strokes. The very compact
box does not really allow cooling air access very well. Please use the 
Multia on its vertical stand, don't put it horizontally ('pizza style').
Replacing the fan with something which pushes around more air is
recommended. Beware of PCI cards with high power consumption.

SCSI:
In case you want to change the internal hard drive: the internal flat cable
running from the PCI riser board to the 2.5" (!!) hard drive has a finer pitch
than the standard SCSI flat cables. Otherwise it would not fit on the 2.5"
drives. There are also riser cards that have a standard-pitch SCSI cable
attached to it, which will fit an ordinary SCSI disk.

I recommend against trying to cram a replacement hard disk inside. Use the
external SCSI connector and put your disk in an external enclosure. Multias run
hot enough as-is. In most cases you will have the external high density 
50pin SCSI connector but some Multia models came without disk and may lack
the connector. Something to check before buying one.

The kernel configuration file for a Multia kernel must contain:
        options         DEC_AXPPCI_33
	cpu		EV4

More info:
Recommended reading on Multia can be found at
	http://www.netbsd.org/Ports/alpha/multiafaq.html
	http://www.brouhaha.com/~eric/computers/udb.html

*
* Personal Workstation ("Miata")
*

The Miata is a small tower machine intended to be put under a desk. There
are multiple Miata variants. The original Miata is the MX5 model. Because 
it suffers from a number of hardware design flaws a redesign was performed,
yielding the MiataGL. Unfortunately the boxes are quite indistinguishable.
An easy check is to see if the back of the machine sports two
USB connectors. If yes, it is a MiataGL. 

System designations look like "Personal Workstation 433a". Personal
Workstation, being a bit of a mouthful, is often abbreviated to PWS.
This means it has a 433 MHz CPU, and started life as a WinNT workstation 
(the trailing 'a'). Systems designated from day 1 to run Tru64 
Unix or OpenVMS will sport '433au'. WinNT-Miatas are likely
to come pre-configured with an IDE CDROM drive. So, in general systems
are named like PWS[433,500,600]a[u]. 

There was also a Miata model with a special cooling system by Kryotech. 
That one has a different enclosure.

Features:

- 21164A EV56 Alpha CPU, at 433, 500 or 600MHz 
- 21174 Core Logic ("Pyxis") chip set
- on-board Bcache / L3 cache: 0, 2 or 4 Mbytes (uses a cache module)
- memory bus: 128 bits wide, ECC protected
- memory: Miata uses unbuffered SDRAMs, 
	  installed in pairs of 2,
	  6 DIMM sockets
	  1.5 Gbytes max
- on-board Fast Ethernet based on:
  - MX5 uses a 21142 or 21143 Ethernet chip dependent on the version of the
    PCI riser card, 
  - MiataGL has a 21143 chip)
  the bulkhead can be 10/100 UTP, or 10 UTP/BNC.
- 2x on-board [E]IDE based on:
  - MX5: CMD646
  - MiataGL: Cypress 82C693
- 1x Ultra-Wide SCSI Qlogic 1040 [MiataGL only]
- expansion: 2 64-bit PCI slots
	     3 32-bit PCI slots (behind a DEC PCI-PCI bridge chip)
	     3 ISA slots (physically shared with the 32 bit PCI slots, via
		          a Intel 82378IB PCI to ISA bridge chip)
- 2x 16550A serial port
- 1x parallel port 
- PS/2 keyboard & mouse port
- USB interface [MiataGL only]
- embedded sound based on an ESS1888 chip

CPU mainboard and PCI 'riser' board: 
the Miata is divided into two printed circuit boards. 
The lower board in the bottom of the machine has the PCI 
and ISA slots and things like the sound chip etc. The top board
has the CPU, the Pyxis chip, memory etc. Note that MX5 and the MiataGL use
a different PCI riser board. This means that you cannot just upgrade to
a MiataGL CPU board (with the newer Pyxis chip) but that you will also need
a different riser board. Apparently an MX5 riser with a MiataGL CPU board
will work but it is definitely not a supported or tested configuration.
Everything else (cabinet, wiring etc etc) is identical for MX5 and MiataGL.

DMA bug: 
MX5 has problems with DMA via the 2 64-bit PCI slots when this DMA
crosses a page boundary. The 32 bit slots don't have this problem because the
PCI-PCI bridge chip does not allow the offending transfers. The SRM code 
knows about the problem and refuses to start the system if there is a PCI
card in one of the 64bit slots that it does not know about. Cards that are
'known good' to the SRM are allowed to be used in the 64bit slots. 

If you want to fool the SRM you can type "set pci_device_override" at
the SRM prompt. Just don't complain if your data mysteriously gets mangled.

The complete command is:

	set pci_device_override <vendor_id><device_id>
	e.g. set pci_device_override 88c15333

A more radical approach is to use: 
	
	set pci_device_override -1

This disables PCI ID checking altogether, so that you can stick in any
random PCI card without its ID getting checked. Again: do this on your own
risk.

The kernel reports it when it sees a buggy Pyxis chip:
Sep 16 18:39:43 miata /kernel: cia0: Pyxis, pass 1
Sep 16 18:39:43 miata /kernel: cia0: extended capabilities: 1<BWEN>
Sep 16 18:39:43 miata /kernel: cia0: WARNING: Pyxis pass 1 DMA bug; no
bets...

A MiataGL probes as:
Jan  3 12:22:32 miata /kernel: cia0: Pyxis, pass 1
Jan  3 12:22:32 miata /kernel: cia0: extended capabilities: 1<BWEN>
Jan  3 12:22:32 miata /kernel: pcib0: <2117x PCI host bus adapter> on cia0

MiataGL does not have the DMA problems of the MX5. PCI cards that make
the MX5 SRM choke when installed in the 64bit slots are accepted without 
problems by the MiataGL SRM.

The latest mainboard revisions of MX5 contain a hardware workaround for the
bug. The SRM does not know about the ECO and will complain about unknown cards
as before. So does the FreeBSD kernel by the way.

EIDE:
The Miata SRM can boot from IDE CDROM drives. Hard disk boot is known to work 
for both MiataGL and MX5 disks, so you can root FreeBSD from an IDE disk. Speeds
on MX5 are around 14 Mbytes/sec assuming a suitable drive. The CMD646 chip will
support up to WDMA2 mode as the silicon is too buggy for use with UDMA.

PCI-PCI bridge:
The MiataGL has a faster PCI-PCI bridge chip on the PCI riser card than 
some of the MX5 riser card versions. Some of the MX5 risers have the *same*
chip as the MiataGL. All in all there is a lot of variation.

Sound: 
Both MX5 and MiataGL have an on-board sound chip, an ESS1888. It emulates
a SoundBlaster and can be enabled by putting 

	device pcm0                                                           
	device sbc0    

in your kernel configuration file.

Cache: 
in case your Miata has the optional cache board installed make sure
it is firmly seated. A slightly loose cache has been observed to cause
weird crashes (not surprising obviously, but maybe not so obvious when
troubleshooting). The cache module is identical between MX5 and MiataGL.

Installing a cache module achieves, apart from a 10-15% speed increase (based 
on buildworld elapsed time), a *decrease* for PCI DMA read bandwidth from 
64bit PCI cards. A benchmark on a 64-bit Myrinet card resulted in a decrease
from 149 Mbytes/sec to 115 Mbytes/sec. Something to keep in mind when doing 
really high speed things with 64 bit PCI adapters.

Keyboard:
If you experience SRM errors like "ERROR: scancode 0xa3 not supported
on PCXAL" after halting FreeBSD you should update your SRM firmware 
to V7.2-1 or later. This SRM version is first available on the Firmware
Update CD V5.7, or on www.compaq.com The problem is fixed on both Miata MX5
and Miata GL.

USB:
Supported by FreeBSD 4.1 and later.

Power:
disconnect the power cord before dismantling the machine, the soft-power
switch keeps part of the logic powered even when the machine is switched
off.

The kernel configuration file for a Miata kernel must contain:
	options         DEC_ST550               
	cpu		EV5

*
* DEC3000 family (the "Bird" machines)
*

The DEC3000 series were among the first Alpha machines ever produced. They
are based on an I/O bus called the Turbo Channel (TC) bus. These
machines are built like tanks (watch your back). 

DEC3000 can be subdivided in DEC3000/500-class and DEC3000/300-class. 
The DEC3000/500-class is the early high-end workstation/server Alpha family. 
Servers use serial consoles, workstations have graphics tubes. 
DEC3000/300-class is the lower-cost workstation class.

DEC3000/500-class are quite fast (considering their age) thanks to the 
good memory design. DEC3000/300 is crippled compared to DEC3000/500 because
of its much narrower memory bus.

They are called 'Birds' because their internal DEC code names were bird
names:

	DEC3000/400     'Sandpiper' 133MHz CPU, desktop
	DEC3000/500     'Flamingo'  150MHz CPU, floor standing
	DEC3000/500X    'Hot Pink'  200MHz CPU, floor standing
	DEC3000/600                 175MHz CPU, desktop
	DEC3000/700,         	    225MHz CPU, floor standing
	DEC3000/800,	            200MHz CPU, floor standing
	DEC3000/900,	            275MHz CPU, floor standing

	DEC3000/300 	'Pelican'   150MHz CPU, desktop, 2 TC slots
        DEC3000/300X                175MHz CPU, desktop, 2 TC slots
	DEC3000/300LX	            125MHz CPU, desktop, 2 TC slots
	DEC3000/300L	            100MHz CPU, desktop, no TC slots
		

Features:
- 21064 CPU  (100 to 200 MHz)
  21064A CPU (225 to 275 MHz)
- memory bus: 256 bit, with ECC 	[DEC3000/500-class]
	       64 bit, with ECC		[DEC3000/300-class]
- memory: - proprietary 100pin SIMMs 
            installed in sets of 8 	[DEC3000/500-class]
 	  - PS/2 style 72pin 36 bit FPM SIMMs, 70ns or better
	    used in pairs of 2		[DEC3000/300-class]
- Bcache / L2 cache: varying sizes, 512 kB to 2 Mbyte
- built-in 10Mbit Ethernet based on a Lance 7990 chip, AUI and UTP 
- one or two SCSI buses based on a NCR53C94 or a NCR53CF94-2 chip 
- 2 serial ports based on Zilog 8530 (one usable as a serial console)
- embedded ISDN interface
- on-board 8 bit sound 
- 8 bit graphics on-board [some models] or via a TC card [some other models]

SCSI:
Currently DEC3000 machines can only be used diskless on FreeBSD/alpha. The
reason for this is that the SCSI drivers needed for the TC SCSI adapters
were not brought into CAM that the current FreeBSD versions use. TC option
cards for single (PMAZ-A) or dual fast SCSI (PMAZC-AA) are also available.
And currently have no drivers n FreeBSD either.

DEC3000/300 has 5Mbytes/sec SCSI on-board. This bus is used for both internal
and external devices. DEC3000/500 has 2 SCSI buses. One is for internal 
devices only, the other one is for external devices only.

Floppy devices found in the DEC3000s are attached to the SCSI bus (via a
bridge card). This makes it possible to boot from them using the same device
names as ordinary SCSI harddisks (>>> BOOT DKA300 for example).

Expansion:
The 3000/300 series has a half-speed TurboChannel compared to the other
3000 machines. Some TC expansion cards have troubles with the half-speed
bus. Caveat empor.

ISDN interface:
does not work on FreeBSD (to be honest I don't think there is any 
operating system, including Tru64 Unix, that can use it). 

Memory:
DEC3000/300-class uses standard 36 bit, 72 pin Fast Page Mode SIMMs.
EDO SIMMs, 32 or 33 bit SIMMs all will not work in Pelicans.
For 32Mbyte SIMMs to work on the DEC3000/300-class the presence detect 
bits/pins of the SIMM must correspond to what the machine expects. If they
don't, the SIMM is 'seen' as a 8 Mbyte SIMM. 8 Mbyte and 32 Mbyte SIMMs can 
be mixed, as long as the pairs themselves are identical.

When you find yourself in need of fixing 32Mbyte SIMMs that lack correct
presence bits the following info might be of use:

There are four presence detection bits on PS/2 SIMMs.  Two of       
the bits indicate the access time.  The other two indicate the memory size.

At one end of the simm there are two rows of four solder pads.  One
row is connected to Vss (GND) and the other is connected to pins
67 (PRD1), 68 (PRD2), 69 (PRD3), 70 (PRD4).                         

If you bridge a pair of pads with a small resistor or a drop of  
solder you ground that particular bit.

	PRD1    PRD2    mem. size
	-----------------------------
	GND     GND     4 or 64 Mbyte
	Open    GND     2 or 32 Mbyte
	GND     Open    1 or 16 Mbyte
	Open    Open    8 Mbyte

	PRD3    PRD4    access time
	------------------------------
	GND     GND     50 or 100 nsec
	Open    GND     80 nsec
	GND     Open    70 nsec
	Open    Open    60 nsec

DEC3000/500-class can use 2, 4, 8, 16 and 32 Mbyte 100pin SIMMs. 
Note that the maximum memory size varies from system to system, 
desktop machines have sacrificed box size for less memory SIMM sockets. 
Given enough sockets and enough SIMMs you can get to 512 Mbytes maximum.
This is one of the main differences between floor standing and desktop
machines, the latter have far less SIMM sockets.

Sound:
is not supported on any of the Birds.

Graphics:
The is no X-Windows version available for the TC machines. 
DEC3000/300 needs a serial console. DEC3000/500-class might
work with a graphical console. I ran mine with a serial console so I cannot
verify this. 

Birds can be obtained from surplus sales etc. As they are not PCI
based they are no longer actively maintained. TC expansion boards can 
be difficult to obtain these days and support for them is not too good
unless you write/debug the code yourself. Programming information for TC
boards is hard to find. Birds are recommended only if a. you can get them
cheap and b. if you prepared to work on the code to support them better.

For the DEC3000/[4-9]00 series machines the kernel config file must 
contain:
	options         DEC_3000_500           
	cpu		EV4

For the DEC3000/300 ("Pelican") machines the kernel config file must
contain:
	options         DEC_3000_300            
	cpu		EV4

*
*Evaluation Board 64plus ("EB64+"), Aspen Alpine
*

In its attempts to popularise the Alpha CPU DEC produced a number of so
called Evaluation Boards. The EB64+ family boards have the following feature
set:

- 21064 or 21064A CPU, 150 to 275MHz 
- memory bus: 128 bit
- memory:  PS/2 style 72 pin 33 bit Fast Page Mode SIMMs, 
	   70ns or better,
           installed in sets of 4
           8 SIMM sockets
           uses parity
- Bcache / L2 cache: 512 kByte, 1 Mbyte or 2 Mbytes
- 21072 ("APECS") chip set 
- Intel 82378ZB PCI to ISA bridge chip ('Saturn')
- dual 16550A serial ports
- NCR/Symbios 53C810 Fast-SCSI
- embedded 10 Mbit Ethernet
- 2 PCI slots
- 3 ISA slots

Aspen Alpine:
Aspen Alpine is slightly different, but is close enough to the EB64+ to
run an EB64+ SRM EPROM (mine does..). The Aspen Alpine does not have 
an embedded Ethernet, has 3 instead of 2 PCI slots. It comes with 2 Mbytes
of cache already soldered onto the mainboard. It has jumpers to select
the use of 60, 70 or 80ns SIMM speeds.

Memory:
36 bits SIMMs work fine, 3 bits simply remain unused.

SRM:
The SRM console code is housed in an UV-erasable EPROM. No easy flash SRM
upgrades for the EB64+ The latest SRM version available for EB64+ is quite
ancient anyway.

SCSI: 
The EB64+ SRM can boot both 53C810 and Qlogic1040 SCSI adapters. Pitfall for
the Qlogic is that the firmware that is down-loaded by the SRM onto the
Qlogic chip is very old. There are no updates for the EB64+ SRM available. 
So you are stuck with old Qlogic bits too. I have had quite some problems
when I wanted to use Ultra-SCSI drives on the Alpine/Qlogic. The
FreeBSD/alpha kernel can be compiled to include a much newer Qlogic firmware
revision. This is not the default because it adds hundreds of kBytes worth
of bloat to the kernel. All of this might mean that you need to use a
non-Qlogic adapter to boot from. 

For the EB64+ class machines the kernel config file must contain:
	options         DEC_EB64PLUS            
	cpu		EV4

*
* Evaluation Board 164 ("EB164, PC164, PC164LX, PC164SX") family
*

EB164 is a newer design evaluation board, based on the 21164A CPU. This
design has been used to 'spin off' multiple variations, some of which are
used by OEM manufacturers/assembly shops. Samsung did its own PC164LX
which has only 32 bit PCI, whereas the DEC variant has 64 bit PCI.

Features:
- 21164A, multiple speed variants [EB164, PC164, PC164LX]
  21164PC 			  [only on PC164SX]
- 21174 (Alcor) chip set
- Bcache / L3 cache:  EB164 uses special cache-SIMMs
- memory bus: 128 bit / 256 bit
- memory:  PS/2 style SIMMs in sets of 4 or 8, 
	   36 bit, Fast Page Mode, uses ECC, [EB164 and PC164]
	   SDRAM DIMMs in sets of 2, uses ECC [PC164SX and PC164LX]
- dual 16550A serial ports
- PS/2 style keyboard & mouse
- floppy controller
- parallel port
- 32 bits PCI
- 64 bits PCI [some models]
- ISA slots via an Intel 82378ZB PCI to ISA bridge chip

Memory:
Using 8 SIMMs for a 256bit wide memory can yield interesting speedups over
a 4 SIMM/128bit wide memory. Obviously all 8 SIMMs must be of the same type
to make this work. The system must be explicitly setup to use the 
8 SIMM memory arrangement. You must have 8 SIMMs, 4 SIMMs distributed 
over 2 banks does not work.

SCSI:
The SRM can boot from Qlogic 10xx boards or the NCR/Symbios 53C810. 
53C825[a] will also work as boot adapter. Diamond FirePort, although 
based on Symbios chips, is not bootable by the PC164SX SRM. 
PC164SX is reported to boot fine with NCR825, NCR875 and NCR876 based cards.

SRM quirks:
PC164 the SRM sometimes seems to loose its variable settings. 
"For PC164, current superstition says that, to avoid losing settings,
you want to first downgrade to SRM 4.x and then upgrade to a 5.x"
Other PC164 owners report they have never seen the problem. 

On PC164SX the AlphaBIOS allows you a selection to select 'SRM' to
be used as console on the next power up. This selection does not appear to
have any effect. In other words, you will get to the AlphaBIOS regardless
of what you select. The fix is to reflash the console ROM with the SRM 
code for PC164SX. This will overwrite the AlphaBIOS and will get you the
SRM console you desire. The SRM code can be found on the Compaq Web site.

IDE:
PC164 can boot from IDE disks assuming your SRM version is recent enough.

Power:
EB164 needs a power supply that supplies 3.3 Volts. PC164 does not implement
the PS_ON signal that ATX power supplies need to switch on. A simple switch
pulling this signal to ground fixes this.

For the EB164 class machines the kernel config file must contain:
        options         DEC_EB164
        cpu             EV5


*
* AlphaStation 200 ("Mustang") and 400 ("Avanti") series
*

The Digital AlphaStation 200 and 400 series systems are early PCI based
workstations for the lower end. The 200 and 250 series is a desktop box, the 
400 series is a desk-side mini-tower.

Features:
- 21064 or 21064A CPU
- DECchip 21071-AA (core logic chip-set) consisting of:
    Cache/memory controller (one 21071-CA chip)
    PCI interface (one 21071-DA chip)
    Data path (two 21071-BA chips)
- Bcache / L2 cache: 512 Kbytes (200 and 400 series)
		     2048KBytes (250 series)
- memory bus: 64 bit
- memory: 8 to 384 MBytes of RAM,
	  70 ns or better Fast Page DRAM,
          in three pairs (200 and 400 series)
	  in two quads, so banks of four. (250 series)
	  uses parity 
- PS/2 keyboard and mouse port
- two 16550 serial ports
- parallel port
- floppy disk interface
- 32 bit PCI expansion slots (3 for 400 series, 2 for 200 & 250 series)
- ISA expansion slots (4 for 400 series, 2 for 200 & 250 series) 
  (some ISA/PCI slots are physically shared)
- embedded 21040-based Ethernet (200 & 250 series)
- embedded NCR/Symbios 53c810 Fast SCSI-2 chip
- Intel 82378IB ("Saturn") PCI-ISA bridge chip
- graphics is embedded TGA or PCI VGA (model dependent)
- 16 bit sound (on 200 & 250 series)

Memory:
the system uses parity memory SIMMs, but it does not need 36 bit wide SIMMs.
33 bit wide SIMMs are sufficient, 36 bit SIMMs are acceptable too. EDO or 32
bit SIMMs will not work. 4, 8, 16, 32 and 64 Mbyte SIMMs are supported.

Sound:
The AS200 & AS250 sound hardware is reported to work OK assuming you have 
the following line in your kernel config file:

	device pcm0 at isa? port 0x530 irq 9 drq 0 flags 0x10011

SCSI:
AlphaStation 200 & 250 series has an automatic SCSI terminator. This means that 
as soon as you plug a cable onto the external SCSI connector the internal
terminator of the system is disabled. It also means that you should not
leave unterminated cables plugged into the machine.

AlphaStation 400 series have an SRM variable that controls termination. In
case you have external SCSI devices connected you must set this SRM
variable using: "set control_scsi_term external". If only internal SCSI devices
are present use: "set control_scsi_term internal"

For the AlphaStation-[24][05]00 machines the kernel config file must contain:
        options         DEC_2100_A50
	cpu		EV4


*
* AlphaStation 500 and 600
*
AS500 and 600 were the high-end EV5 / PCI based workstations. EV6 based
machines have in the meantime taken their place as front runners. AS500 is
a desktop in a dark blue case (TopGun blue), AS600 is a sturdy desk-side box.
AS600 has a nice LCD panel to observe the early stages of SRM startup.

Features:
- 21164 EV5 CPU at 333, 400 or 500 MHz (AS500)
		at 266 or 300 MHz (AS600)
- 21171 or 21172 (Alcor) core logic chip-set
- cache: 2 or 4 Mb L3 / Bcache (AS600 at 266 MHz)
	 4 Mb L3 / Bcache (AS600 at 300 MHz)
	 2 or 8 Mb L3 / Bcache (8 Mb on 500 MHz version only)
         2 to 16 Mb L3 / Bcache (AS600; 3 cache-SIMM slots)
- memory bus: 256 bits, uses ECC
- memory: AS500: industry standard 8 byte wide DIMMs
          	 8 DIMM slots
	  	 installed in sets of 4,
	  	 maximum memory is 1 Gb (512 Mb max on 333 MHz CPUs)
		 uses ECC 
  	  AS600: industry standard 36 bit Fast Page Mode SIMMs
		 32 SIMM slots,
	         installed in sets of 8,
	         maximum memory is 1 Gb
	         uses ECC
- Qlogic 1020 based wide SCSI bus (1 bus/chip for AS500, 2 for AS600)
- 21040 based 10 Mbit Ethernet adapter with both Thinwire and UTP connectors
- expansion: AS500: 3 32-bit PCI slots
	     	    1 64-bit PCI slot
	     AS600: 2 32-bit PCI slot 
                    3 64-bit PCI slots
		    1 PCI/EISA physically shared slot
		    3 EISA slots
		    1 PCI and 1 EISA slot are occupied by default
- 21050 PCI-to-PCI bridge chip
- Intel 82375EB PCI-EISA bridge (AS600 only)
- 2 16550A serial ports
- 1 parallel port
- 16 bit audio Windows Sound System,
  in dedicated slot (AS500)
  in EISA slot (AS600, this is an ISA card)
- PS/2 keyboard and mouse port

SCSI:
Early machines had Fast SCSI interfaces, later ones are Ultra SCSI capable.
AS500 shares its single SCSI bus with internal and external devices. For a
Fast SCSI bus you are limited to 1.8 meters bus length external to the box.
+++ This is what some DEC docs suggest. Did they ever go Ultra?

AS600 has one Qlogic chip dedicated to the internal devices whereas the
other one is dedicated to external SCSI devices.

Memory:
In AS500 DIMMs are installed in sets of 4, in 'physically interleaved'
layout. So, a bank of 4 DIMMs is *not* 4 adjacent DIMMs!

In AS600 the memory SIMMs are placed onto two memory daughter cards. SIMMs
are installed in sets of 8. Both memory daughter cards must be populated
identical. 

PCI:
AS600 has a peculiarity for its PCI slots. AS600 (or rather the PCI
expansion card containing the SCSI adapters) does not allow I/O port 
mapping, therefore all devices behind it must use memory mapping.  
If you have problems getting the SCSI adapters to work, add the following 
option to /boot/loader.rc: 

        set isp_mem_map=0xff                                        
        
This may need to be typed at the boot loader prompt before booting the
installation kernel.                                                 

For the AlphaStation-[56]00 machines the kernel config file must contain:
	options         DEC_KN20AA 
	cpu		EV5

*
* AlphaServer 1000 ("Mikasa"), 1000A ("Noritake") and 800 
*
The AlphaServer 1000 and 800 range of machines is aimed as departmental servers.
They come in quite some variations in packaging and mainboard/cpu. Generally
speaking there are 21064 (EV4) CPU based machines and 21164 (EV5) based
ones. The CPU is on a daughter card, and the type of CPU (EV4 or EV5) must
match the mainboard in use. AlphaServer 800 is a much smaller mini tower
case, it lacks the StorageWorks SCSI hot-plug chassis. The main difference
between AS1000 and AS1000A is that AS1000A has 7 PCI slots whereas AS1000
only has 3 PCI slots and has EISA slots instead. AS800 with an EV5/400 MHz
CPU was later rebranded as a DIGITAL Server 3300[R], AS800 with an EV5/500 MHz
CPU was later rebranded as a DIGITAL Server 3305[R].

Features:
- 21064 EV4 CPU at 200, 233 or 266 MHz
  21164 EV5 CPU at 300, 333 or 400 MHz (or 500 MHz for AS800 only)
- cache:
- memory bus: 128 bit with ECC
- memory:
	AS1000[A]-systems:
          Use 72pin 36 bit Fast Page Mode SIMMs, 70ns or better
	  16 or 20 SIMM slots
	  max memory is 1 Gb
	  uses ECC
	AS800:
	  Uses SDRAM DIMMs.
- embedded VGA (on some mainboard models)
- expansion: 
	3 PCI, 2 EISA, 1 64-bit PCI/EISA combo (AS800)
  	7 PCI, 2 EISA (AS1000A)
 	2 PCI, 1 EISA/PCI, 7 EISA (AS1000)
- embedded SCSI based on NCR/Symbios 810 [AS1000] or Qlogic 1020 [AS1000A]
	
Box:
AS1000 based machines come in multiple boxes. Floor standing, rack-mount,
with or without StorageWorks SCSI chassis etc. The electronics are the
same.

Memory:
  AS1000-systems:
  All EV4 based machines use standard PS/2 style 36 bit 72pin SIMMs in sets 
  of 5. The fifth SIMM is used for ECC.
  All EV5 based machines use standard PS/2 style 36 bit 72pin SIMMs in sets 
  of 4. The ECC is done based on the 4 extra bits per SIMM (4 bits out of 36).
  The EV5 mainboards have 16 SIMM slots, the EV4 mainboards have 20 slots.

  AS800:
  Uses DIMMs in sets of 4. DIMM installation must start in slots marked 
  bank 0. A bank is four physically adjacent slots. The biggest size DIMMs
  must be installed in bank 0 in case 2 banks of different DIMM sizes are
  used. Max memory size is 2Gb.

SCSI:
For AS800 you want to check if your Ultra-Wide SCSI is indeed in Ultra mode.
This can be done using the EEROMCFG.EXE utility that is on the Firmware 
Upgrade CDROM. 
  
For the AlphaServer1000/1000A/800 machines the kernel config file must contain:
	options         DEC_1000A
	cpu		EV4		# depends on the CPU model installed
	cpu		EV5		# depends on the CPU model installed

*
* DS10/VS10/XP900 ("Webbrick") / XP1000 ("Monet") / DS10L ("Slate")
*
Webbrick and Monet are high performance workstations/servers based on the
EV6 CPU and the Tsunami chipset. Tsunami is also used in much higher-end 
systems and as such has plenty of performance to offer. DS10, VS10 and XP900
are different names for essentially the same system. The difference are the 
software and options that are supported. DS10L is a DS10 based machine in a 1U 
high rackmount enclosure. DS10L is intended for ISPs and for HPTC clusters
(e.g. Beowulf).

Monet has, by 1999 standards, *stunning* (the words of a satisfied
user) memory and I/O system bandwidth.

** Webbrick / Slate

Features:
- 21264 EV6 CPU at 466 MHz
- L2 / Bcache: 2MB, ECC protected
- memory bus: 128 bit via crossbar, 1.3GB/sec to memory
- memory: industry standard 200 pin 83 MHz buffered ECC SDRAM DIMMs
	  4 DIMM slots (2 for DS10L)
	  installed in pairs of 2
	  max memory is 2 Gb (1Gb for DS10L)
- 21271 Core Logic chipset ("Tsunami")
- 2 on-board 21143 Fast Ethernet controllers
- AcerLabs M5237 (Aladdin-V) USB controller
- AcerLabs M1533 PCI-ISA bridge   
- AcerLabs Aladdin ATA-33 controller 
- embedded dual EIDE 
- expansion: 3 64-bit PCI slots
             1 32-bit PCI slots
	     DS10L has a single 64bit PCI slot
- 2x 16550A serial ports
- 1x parallel port
- 2x USB
- PS/2 keyboard & mouse port        

Power:
The system has a smart power controller. This means that parts of the system
remain powered when it is switched off (like an ATX-style PC power supply).
Before servicing the machine remove the power cord.

Case:
Webbrick is shipped in a desktop-style case similar to the older 21164
"Maverick" workstations but which offers much better access to        
components. If you intend to build a farm you can rackmount them in a 19"
rack, they are 3U high. Slate is 1U high but has only one PCI slot.

Memory:
DS10 has 4 DIMM slots. DIMMs are installed as pairs. Please note that 
DIMM pairs are not installed in adjacent DIMM sockets but rather physically
interleaved. DIMM sizes of 32, 64, 128, 256 and 512 Mbytes are supported.

When 2 pairs of identical-sized DIMMs are installed DS10 will use memory 
interleaving for higher performance. DS10L, which has only 2 DIMM slots cannot 
do interleaving.

EIDE:
The base model comes with a FUJITSU 9.5GB ATA disk as its boot device.
FreeBSD/alpha works just fine using EIDE disks on Webbrick. DS10 has 2 IDE 
interfaces on the mainboard.

Expansion:
On the PCI bus 32 and 64 bit cards are supported, in 3.3V and 5V variants.

USB:
Is supported in FreeBSD 4.1 and later.

The kernel config file must contain:
	options         DEC_ST6600    
	cpu		EV5

Contrary to expectation there is no 'cpu EV6' defined for inclusion in the
kernel config file. The 'cpu EV5' is mandatory to keep config(8) happy.

** Monet 

Features:
- 21264 EV6 at 500 MHz
  21264 EV67 at 500 or 667 MHz (XP1000G, codenamed Brisbane)
  CPU is mounted on a daughtercard which is field-upgradable
- L2 / Bcache: 4MB, ECC protected
- memory bus: 256 bit 
- memory: 128 or 256 Mbytes 100 MHz (PC100) 168 pin JEDEC standard,
	  registered ECC SDRAM DIMMs
- 21271 Core Logic chip-set ("Tsunami")
- 1 on-board 21143 Ethernet controller
- Cypress 82C693 USB controller       
- Cypress 82C693 PCI-ISA bridge       
- Cypress 82C693 controller 
- expansion: 2 independent PCI buses (called hoses)
        hose 0: (the upper 3 slots)
             2 64-bit PCI slots    
             1 32-bit PCI slot     
        hose 1: (the bottom 2 slots)
             2 32-bit PCI slots (behind a 21154 PCI-PCI bridge)
	2 of the 64-bit PCI slots are for full-length cards
	all of the 32-bit PCI slots are for short cards
	1 of the 32-bit PCI slots is physically shared with an ISA slot
   	all PCI slots run at 33MHz
- 1x Ultra-Wide SCSI port based on a Qlogic 1040 chip
- 2x 16550A serial port        
- 1x parallel port        
- PS/2 keyboard & mouse port        
- embedded 16-bit ESS ES1888 sound chip
- 2x USB
- graphics options: ELSA Gloria Synergy or DEC/Compaq PowerStorm 3D
	            accelerator cards

Case:
Monet is housed in a mini-tower like enclosure quite similar to the Miata
box.

SCSI:
The onboard Qlogic UW-SCSI chip supports up to 4 internal devices. There is
no external connector for the onboard SCSI.

Memory:
For 500 MHz CPUs 83 MHz DIMMs will do. Compaq specifies PC100 DIMMs for
all CPU speeds. DIMMs are installed in sets of 4, starting with the 
DIMM slots marked '0'. Memory capacity is max 4 Gb. 
DIMMs are installed 'physically interleaved', note the markings of the
slots. Memory bandwidth of Monet is twice that of Webbrick. The DIMMs live
on the CPU daughtercard. Note that the system uses ECC RAM so you need DIMMs
with 72 bits (not the PC-class 64 bit DIMMs)

EIDE:
Is usable / bootable for system disk so FreeBSD can be rooted on an EIDE
disk. Although the Cypress chip has potential for 2 EIDE channels Monet uses
only one of them.

USB:
If you experience problems trying to use the USB interface please check if
the SRM variable "usb_enable" is set to "on". You can change this by
performing: "set usb_enable on" at the SRM >>> prompt.

Expansion:
Don't try to use NCR/Symbios-chip based SCSI adapters in the PCI slots
connected to hose 1. There is a not-yet-found FreeBSD bug that prevents this
from working correctly. Not all VGA cards will work behind the PCI-PCI
bridge (so in slots 4 & 5). Only cards that implement VGA-legacy adressing
correctly will work. Workaround is to put the VGA card 'before' the bridge.

Sound:
The sound chip is not currently supported with FreeBSD. There is work in
progress in this area.

The kernel config file must contain:
	options         DEC_ST6600    
	cpu		EV5

Contrary to expectation there is no 'cpu EV6' defined for inclusion in the
kernel config file. The 'cpu EV5' is mandatory to keep config(8) happy.

** DS20/DS20E ("Goldrush"):

Features:
- 21264 EV6 CPU at 500 or 670 MHz
- dual CPU capable machine
- L2 / Bcache: 4 Mbytes per CPU
- memory bus: dual 256 bit wide with crossbar switch
- memory: SDRAM DIMMs
	  installed in sets of 4
	  uses ECC 
	  16 DIMM slots
	  max. 4Gb
- 21271 Core Logic chip-set ("Tsunami") 
- embedded Adaptec ? Wide Ultra SCSI 
- expansion: 2 independent PCI buses (called hoses)
	     6 64-bit PCI slots (3 per hose)
	     1 ISA slot

Case:
DS20 is housed in a fat cube-like enclosure. The enclosure also
contains a StorageWorks SCSI hot-swap shelf for a maximum of 7 3.5" SCSI
devices. DS20E is a sleeker case, without the StorageWorks shelf.

Embedded SCSI:
The embedded Adaptec SCSI chip on DS20 is disabled and therefore 
not usable under FreeBSD.

CPU:
DS20 can have 2 CPUs installed. FreeBSD/alpha is not currently SMP-capable 
and will only use the primary CPU.

Memory:
If you are using banks of DIMMs of different sizes the biggest DIMMs should
be installed in the DIMM slots marked '0' on the mainboard. The DIMM slots
should be filled 'in order' so after bank 0 install in bank 1 and so on.

Expansion:
Don't try to use NCR/Symbios-chip based SCSI adapters in the PCI slots
connected to hose 1. There is a not-yet-found FreeBSD bug that prevents this
from working correctly. DS20 ships by default with an NCR on hose 1 so you
have to move this card before you can install/boot FreeBSD on it.

The kernel config file must contain:
	options         DEC_ST6600    
	cpu		EV5

Contrary to expectation there is no 'cpu EV6' defined for inclusion in the
kernel config file. The 'cpu EV5' is mandatory to keep config(8) happy.

** AlphaPC 264DP / UP2000
	<need more info on this one; please check for correctness>

Features:
- 21264 EV6 CPU at 670 MHz
- dual CPU capable 
- L2 / Bcache: 4 Mbytes per CPU
- memory bus: 256 bit 
- memory: SDRAM DIMMs
	  installed in sets of 4
	  uses ECC 
	  16 DIMM slots
	  max. 4Gb
- 21272 Core Logic chip-set ("Tsunami")
- embedded Adaptec AIC7890/91 Wide Ultra SCSI 
- 2x embedded IDE based on Cypress 82C693 chips
- embedded USB via Cypress 82C693
- expansion: 2 independent PCI buses (called hoses)
	     6 64-bit PCI slots (3 per hose)
	     1 ISA slot

Memory:
A maximum of 2Gb memory is supported by FreeBSD.

CPU:
DP264 can have 2 CPUs installed. FreeBSD/alpha is not currently SMP-capable 
and will only use the primary CPU.

Embedded SCSI:
The on-board Adaptec is not bootable but works with FreeBSD 4.0 and later
as a datadisk-only SCSI bus.

Embedded IDE:
Busmaster DMA is supported on the first IDE interface only.

The kernel config file must contain:
	options         DEC_ST6600    
	cpu		EV5

Contrary to expectation there is no 'cpu EV6' defined for inclusion in the
kernel config file. The 'cpu EV5' is mandatory to keep config(8) happy.

*
* AlphaServer 2000 ("DemiSable"), 2100 ("Sable"), 2100A ("Lynx")
*
	<need more info on this one; please check for correctness>

The AlphaServer 2[01]00 machines are aimed as departmental servers.
This is medium iron, not a hobbyist system. These are multi-CPU machines, 
up to 2 CPUs (AS2000) or 4 CPUs (2100[A]) can be in a single machine. 
Both floorstanding and 19" rackmount boxes exist. Rackmount variations have
different numbers of I/O expansion slots, different max number of CPUs and
different maximum memory size. Some of the boxes come with an integral
StorageWorks shelf to house hotswap SCSI disks. 

Features:
- 21064 EV4 CPU[s] at 200, 233, 275 MHz
- 21164 EV5 CPU[s]s at 250, 300, 375 MHz
- cache: varies in size with the CPU model; 1, 4 or 8Mbyte per CPU
- embedded floppy controller
- embedded 10Mbit 21040 ethernet
- 2 serial ports
- 1 parallel port
- PS/2 style keyboard & mouse port

NOTE: Lynx support is currently flagged as experimental due to lack of
      testing / test hardware.

CPU:
The CPUs spec-ed as 200 Mhz are in reality running at 190 MHz.

Memory:
The machines use dedicated memory boards. These boards live on a 128 bit 
C-bus shared with the CPU boards. DemiSable supports up to 1Gb, Sable up 
to 2Gb. One of the memory bus slots can either hold a CPU or a memory card.
Some memory board modules house SIMMs. There are also memory modules that
have soldered-on memory chips instead of SIMMs. SIMM boards are used in sets 
of eight 72-pin 36 bit FPM memory of 70ns or faster. SIMM types supported 
are 1Mb x36 bit (4 Mbyte) and 4Mb x36 bit (16 Mbyte). Each memory board 
can house 4 banks of SIMMs. SIMM sizes can not be mixed on a single memory
board.

Embedded SCSI:
Both Sable, DemiSable and Lynx have NCR810 based Fast SCSI onboard.

Expansion:
DemiSable has 7 EISA slots and 3 PCI slots. Sable has 8 EISA and 3 PCI
slots. Lynx, being newer, has 8 PCI and 3 EISA slots. Make sure you run the
EISA Configuration Utility (from floppy) when adding/change expansion cards
in EISA slots.

	NOTE: EISA slots are currently unsupported, but the Compaq Qvision
	      EISA VGA adapter is treated as an ISA device. It therefore
	      works OK as a console.

Power:
The machines can be equipped with redundant power supplies.

The kernel config file must contain:
       options         DEC_2100_A500
       cpu             EV4
       cpu	       EV5

*
* AlphaServer 4100 ("Rawhide")
*
	<need more info on this one; please check for correctness>

The AlphaServer 4100 machine is aimed as an enterprise server.
Expect a 30" high pedestal cabinet or alternatively the same system box in a
19" rack. This is medium iron, not a hobbyist system. 
These are multi-CPU machines, up to 4 CPUs can be in a single
machine.  Basic disk storage is housed in one or two StorageWorks shelves
at the bottom of the pedestal. The Rawhides intended for the NT market are
designated DIGITAL Server 7300 (5/400 CPU), DIGITAL Server 7305 (5/533 CPU).
A trailing R on the partnumber means a rackmount variant.

Features:
- 21164 EV5 CPUs at 266, 300 MHz
  21164A EV56 CPUs at 400, 466, 533 and 600 Mhz
- cache: 4 Mbytes per CPU (EV5 300 MHz was also available cache-less)
	 8 Mbytes (EV5 600Mhz only)
- memory bus: 128 bit with ECC
- embedded floppy controller
- 2 serial ports
- 1 parallel port
- PS/2 style keyboard & mouse port

Memory:
Rawhide uses a maximum of 8 RAM modules. These modules are used in pairs
and supply 72 bits to the bus (this includes ECC bits). Memory can be EDO
RAM or synchronous DRAM. A fully populated Rawhide has 4 pairs of memory
modules. Given the choice use SDRAM for best performance. The highest 
capacity memory board must be in memory slot 0. A mix of memory board sizes
is allowed. A mix of EDO and SDRAM is also reported as working (assuming you
don't try to mix EDO and SDRAM in one module pair).

Embedded SCSI:
Rawhide has a embedded NCR810 Fast SCSI bus.

Expansion:
Rawhides are available with a 8 64-bit PCI / 3 EISA slot expansion backplanes
(called 'Saddle' modules). There are 2 seperate PCI buses, PCI0 and PCI1.
PCI0 has 1 dedicated PCI slot and (shared) 3 PCI/EISA slots. PCI0 also has a
PCI/EISA bridge that drives things like the serial and parallel ports,
keyboard/mouse etc. PCI1 has 4 PCI slots and an NCR810 SCSI chip.

	NOTE: EISA slots are currently unsupported, but the Compaq Qvision
	      EISA VGA adapter is treated as an ISA device. It therefore
	      works OK as a console.

Power:
The system employs an I2C based power controller system. If you want to be
sure all power is removed from the system pull the mains cables from the
system.

The kernel config file must contain:
       options         DEC_KN300
       cpu             EV5

*
* AlphaServer 8200 and 8400 ("TurboLaser")
*
The AlphaServer 8200 and 8400 machines are aimed as enterprise servers.
Expect a tall 19" cabinet (8200) or fat (8400) 19" rack. This is big iron,
not a hobbyist system. These are multi-CPU machines, up to 12 CPUs can be in
a single machine. The TurboLaser System Bus (TLSB) allows 9 nodes on the
AS8400 and 5 nodes on the AS8200. TLSB is 256 bit data, 40 bit address
allowing 2.1 Gbytes/sec. Nodes on the TLSB can be CPUs, memory or I/O. A 
maximum of 3 I/O ports are supported on a TLSB. Basic disk storage is housed
in a StorageWorks shelf.

Features: 
- 21164 EV5 CPUs at up to 467 MHz
  21264 EV67 CPUs at up to 625 MHz
  one or two CPUs per CPU module
- cache: 4Mbytes per CPU
- memory bus: 256 bit with ECC
- memory:
	uses big memory modules that plug into the TLSB, which in turn
	hold special SIMM modules.
	memory modules come in varying sizes, up to 2 Gbytes a piece.
	uses ECC (8 bites per 64 bits of data)
	7 modules max for AS8400, 3 modules max for AS8200
	maximum memory is 14 Gbytes
- expansion:
	3 system 'I/O ports' that allow up to 12 I/O channels
	each I/O channel can connect to XMI, Futurebus+ or PCI boxes
       
Memory:
FreeBSD supports (and has been tested with) up to 2 Gbytes of memory on 
TurboLaser.

CPU:
TurboLaser is very much a multiprocessor machine. Currently FreeBSD only
uses one CPU.

Expansion:
Only PCI expansion is supported on FreeBSD. XMI or Futurebus+ (which 
are AS8400 only) are both unsupported.

The I/O port modules are designated KFTIA or KFTHA. The I/O port modules
supply so called 'hoses' that connect to up to 4 (KFTHA) PCI buses or 1
PCI bus (KFTIA). KFTIA has embedded dual 10baseT Ethernet, single FDDI,
3 SCSI Fast Wide Differential SCSI buses and a single Fast Wide Single Ended
SCSI bus. The FWSE SCSI is intended for the systems CDROM.

KFTHA can drive via each of its 4 hoses a DWLPA or DWLPB box. The DWLPx
house a 12 slots 32 bit PCI backplane. Physically the 12 slots are 3 4-slot
buses but to the software it appears as a single 12 slots PCI bus. A fully
expanded AS8x00 can have 3 (I/O ports) times 4 (hoses) times 12 (PCI
slots/DWLPx) = 144 PCI slots. The maximum bandwidth per KFTHA is 500
Mbytes/second. DWLPA can also house 8 EISA cards, 2 slots are PCI-only, 2
slots are EISA only. Of the 12 slots 2 are always occupied by an I/O and
connector module.

For best performance distribute high bandwidth (FibreChannel, Gigabit Ethernet)
over multiple hoses and/or multiple KFTHA/KFTIA.

Currently PCI expansion cards containing PCI bridges have not been tested.

Embedded SCSI:
The single ended SCSI bus on the KFTIA will turn up as the fourth (!) 
SCSI bus. The 3 differential SCSI buses of the KFTIA precede it. 

Console:
AS8x00 are generally run with serial consoles. Some newer machines might
have a graphical console of some sorts but FreeBSD has only been tested on
a serial console.

For serial console usage either change /etc/ttys to have:

        console "/usr/libexec/getty std.9600"   unknown   on secure

as the console entry, or add

        zs0     "/usr/libexec/getty std.9600"   unknown   on secure

and make the zs node:

        mknod  /dev/zs0  c 135 0

For the AlphaServer 8x00 machines the kernel config file must
contain:
	options         DEC_KN8AE	# Alpha 8200/8400 (Turbolaser)
        cpu             EV5 

Supported hardware overview
---------------------------

Word of caution: the installed base for FreeBSD/alpha is not nearly as large
as for FreeBSD/Intel. This means that the enormous variation of PCI/ISA
expansion cards out there has much less chance of having been tested on
alpha than on Intel. This is not to imply they are doomed to fail, just that
the chance of running into something never tested before is much greater.
GENERIC contains things that are known to work on Alpha only.

- Expansion buses: PCI and ISA are fully supported. Turbo Channel is not
in GENERIC and has limited support (see the relevant machine model info).
The MCA bus is not supported. The EISA bus is not supported for use with
EISA expansion cards as the EISA support code is lacking. ISA cards in EISA 
slots are reported to work. The Compaq Qvision EISA VGA card is driven in
ISA mode and works OK as a console.

- Floppy drives: 1.44 Mbyte and 1.2 Mbyte floppy drives are supported.
2.88Mbyte drives sometimes found in Alpha machines are supported up to
1.44Mbyte.

- ATA / ATAPI (IDE): are supported via the ata driver framework. As most
people run their Alphas with SCSI disks it is not as well tested as SCSI. Be
aware of bootability restrictions for IDE disks. See the machine specific
information.

- SCSI: full support via the CAM layer for Adaptec 2940x (AIC7xxx
chip-based), Qlogic family and NCR/Symbios. Be aware of the machine-specific
bootability issues for the various adapter types.

- FibreChannel: the Qlogic QL2x00 FibreChhannel host adapters are fully
supported.

- graphics console/keyboard/mouse: in general the SRM console emulates 
a VGA-compatibility mode on PCI VGA cards. This is, however, not guaranteed 
to work by Compaq/DEC for each and every card type out there. When the SRM 
thinks the VGA is acceptable FreeBSD will be able to use it. The console driver
works just like on a FreeBSD/intel machine. The TGA video graphics which 
is embedded on for example Multia does *not* work with FreeBSD. TGA based
PCI cards are also *not* supported. Please note that VESA modes are not
supported on Alpha, so that leaves you with 80x25 consoles

- serial ports: the 'PC standard' serial ports found on most Alphas are 
supported. For TurboChannel machines the serial ports are also supported.

- ISDN (i4b): is not supported on FreeBSD/alpha

Acknowledgments
----------------

In compiling this file I used multiple information sources, but
http://www.netbsd.org proved to be an invaluable source of information.
If it wasn't for NetBSD/alpha there probably would not be a FreeBSD/alpha
in the first place.

People who kindly helped me with creating this document:

- Nick Maniscalco <nmanisca@vt.edu>
- Andrew Gallatin <gallatin@cs.duke.edu>
- Christian Weisgerber <naddy@mips.rhein-neckar.de>
- David O'Brien <obrien@NUXI.com>
- Wim Lemmers, Compaq
- Matthew Jacob <mjacob@feral.com>
- Eric Schnoebelen <eric@cirr.com>
- Chuck Robey <chuckr@picnic.mat.net>
- Mike Smith <msmith@FreeBSD.ORG>
- Peter Jeremy <peter.jeremy@alcatel.com.au>
- Dolf de Waal <l.j.de.waal@kader.hobby.nl>
- Wouter Brackman, Compaq
- Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>
- Peter van Dijk <petervd@vuurwerk.nl>
