Unfortunately, I can't give you one link that will show you everything. The best site for this, John Carcich's site, has been down for almost a year.
There are plenty of Tbred/Barton/etc sites but not old school Tbird/Spitfire sites, which talk about doing the FID pins and the BP_FID pins.
Here's a couple sites that will help.
<A HREF="
http://www.ocinside.de/index_e.html" target="_new">
http://www.ocinside.de/index_e.html</A> (English version, - Click "Workshop")
Look for the pinmod guide for XPs. It won't talk about the FID pins just the BP_FID pins. Actually it doesn't even label the pins either. It just uses a picture.
Important: Make sure you use the "Socket View" if you plan on doing the wire-in-socket mod.
Here is another good site
<A HREF="
http://fab51.com/index_e.html" target="_new">FAB51.COM</A> (English version)
It will teach you every thing you need to know about the multiplier encoding. Tbirds/Spitfires are real easy. XPs (Palominos and up) have complicated, remapped multipliers which makes the encoding tricky to remember.
Basically the multipliers are encoded in binary. The bridges, BP_FID pins, and FID pins control multipliers 0.5x, 1x, 2x, 4x, and 8x. You don't have to worry about 8x with your Spitfire Duron.
The combination of 0.5x - 4X multipier bits give you a range of 0X thru 7.5x.
There is a 3X offset which means when you add up all the bits you then add 3X to the total.
This changes the range from 0X thru 7.5X to 3X thru 10.5X. This is exactly how multipliers were were code for old Duron laptops, although I dont't think were ever 300 Mhz or 350 Mhz Duron laptops released to the public.
For desktops the 4 lowest combinations were remapped to make to be useful for high speed (at the time) processors. If I recall (I can look it up later) 3X, 3.5x, 4X, and 4.5X were remapped to 11x, 11.5x, 12X, and 13X, respectively. I can't remember what bit combination remapped to 14X but the old Thunderbird 1400 (14X) was troublesome on a lot of motherboards of the day.
As for the pins. Get yourself a copy of the pin diagram from AMD's site. Make sure it's the "Top View". Marking the diagram with your own notes will really help.
Here is a quick pin/multiplier bit table.<pre>
Mult. BP_FID FID
Pin Pin
0.5X AN27 W1
1X AL27 W3
2X AN25 Y1
4X AL25 Y3
8X AJ27 no FID pin for 8X</pre><p>
Here's an example mod.
Let's say you want to encode a 9X multiplier (a good starting point for a Spitfire Duron).
- You are not using 11x thru 14X so you don't have to worry about a re-map.
- Now you subtract the 3X offset. This means you want to encode 6X, 9X (desired multiplier) - 3X (offset) = 6X.
- Set the bits as follows:
0.5X (LOW) + 1X (LOW) + 2X (HIGH) + 4X (HIGH) = 6X total multiplier
(correction: 6X now encoded instead of 5X. Sorry)
Remember that HIGH means logic HIGH, pin connected to Vcc (VCore). LOW means logic LOW, pin connected to Vss (Ground).
When you get the AMD Athlon pin diagram you will be able to see all the nearby locations for Vcc and Vss, relative to the BP_FID and FID pins.
When you move on to XPs you don't need to wire the FID pins, just the BP_FID pins. Well, perhaps you do with Palominos. (I can't remember).
That's my crash course. The site links have more detailed information.
<b>A mind is a terrible thing</b><P ID="edit"><FONT SIZE=-1><EM>Edited by phsstpok on 01/19/05 07:46 PM.</EM></FONT></P>