VOGONS


First post, by SodaSuccubus

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So I found a dismantled early Compaq socket 5 based machine, a"Compaq Presario 7170"in storage and decided to make it complete again.

http://www.uncreativelabs.de/th99/m/C-D/33436.htm
Here's a spec sheet for its motherboard.

I'd like to toss a P133 or 166 in the machine but unfortunately can't seem to get it running at full speed. Only 100mhz max.

I found another thread here about someone else apperently trying to do the same thing and came across this post:

SSTV2 wrote on 2019-09-18, 02:23:
Soldering isn't even necessary. You can just wrap a single wire strand around Vss (ground) and a BF0 pin to set CPU multiplier t […]
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Soldering isn't even necessary. You can just wrap a single wire strand around Vss (ground) and a BF0 pin to set CPU multiplier to 2x, inserting a thin wire between Vss and BF0 in the socket would also do the trick. I used this trick on a IBM 330-p75 to set CPU multiplier to 3x. If your 133MHz P1 was manufactured in 1997+, it has a good chance of running @ 166 or even 200MHz freq.

|BF0|BF1|mult.|
| 1 | 1 |1.5x |
| 0 | 1 |2.0x |
| 0 | 0 |2.5x |
| 1 | 0 |3.0x |

*1 - high, 0 - low.

Does anyone have a visual on that?I have some copper wire, so do I just strip it a bit and stick that in the respective holes on the socket before putting in the CPU? Iv never done this before

Here's a picture of the socket on the board in-question:

IMG_20201103_184820.jpg
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Reply 1 of 1, by andrea

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iz8OcZ2.png

Here's the pinout from the datasheet flipped as if you are looking into the socket to match your picture.

Use 2 small strands of copper (I usually pull them from a piece of mains wire) bent in a U shape and dropped in the right holes to ground BF0 and BF1 for 2.5x (P166). As there's no convenient VSS near BF0 link it to BF1 since it' going to be grounded anyway.

For a P133 it's a bit more annoying as you have to ground only BF0 which has no VSSs nearby. As your quote says if it's a later production unit it will also run at 166 likely.