My Mad B&W G3 Setup!

[Phipli]

.... I'll give you 1 guess on whether I knew that trick ;-)


By changing the PLL?

Oh gosh! It's just a jumper block!

(S = Jumper present or "Set", " " = no jumper)

            Multiple     | 4 | 3 | 2 | 1 |
            - -----------+---+---+---+---+
            3x   300 MHz |   | S | S | S |
            - -----------+---+---+---+---+
            3.5x 350 MHz |   |   |   | S |
            - -----------+---+---+---+---+
            4x   400 MHz |   | S |   | S |
            - -----------+---+---+---+---+
            4.5x 450 MHz | S |   |   |   |
            - -----------+---+---+---+---+
            5x   500 MHz |   | S |   |   |
            - -----------+---+---+---+---+

So, upgrading from 350MHz to 400MHz involves adding a jumper at jumper 3. I'm not massively into upgrading the performance of vintage Macs, mostly because I want the experience of the period. But I'm happy to do period-correct, options. Hence, my PB1400cs/117 upgraded to PB1400c/166. So I'd certainly be up for upgrading a 350MHz B&W G3 to 400MHz!

But I wouldn't upgrade a PB1400 to a G3, or a 250MHz PPC603e. I wouldn't upgrade the B&W G3 to 1GHz or swap for a G4 if that was possible.

I wonder if I can just pull out the metal prongs from a jumper I have and insert them into the block?

They're 2mm jumpers. I might have some around if I have a rummage. I know I bought a bag of them at one point.

 

[Snial]

They're 2mm jumpers. I might have some around if I have a rummage. I know I bought a bag of them at one point.

Interesting, I also might have some on some junk electronics (likely some bust 3.5" HDs).

 

[Snial]

They're 2mm jumpers. I might have some around if I have a rummage. I know I bought a bag of them at one point.

Hi @Phipli ! I found a 4GB Seagate SCSI HD with quite a few 2mm jumpers and an ST M28F101 -150 which is a 12V Flash with the same pinout and speed!

I think it might be OK to cannibalise it as there's a distinct rattle when I twist it back and forth. It's probably dead.




-cheers from Julz

 

[Phipli]

Hi @Phipli ! I found a 4GB Seagate SCSI HD with quite a few 2mm jumpers and an ST M28F101 -150 which is a 12V Flash with the same pinout and speed!

I think it might be OK to cannibalise it as there's a distinct rattle when I twist it back and forth. It's probably dead.

View attachment 99220


-cheers from Julz

There are more jumpers here by the look of it :



I recommend using a 512k ROM as I've never had much luck with the modified ROM. If you want it to work first time.

 

[Snial]

There are more jumpers here by the look of it :

View attachment 99221

I think you're right! I saw they might be when I posted the photo.

I recommend using a 512k ROM as I've never had much luck with the modified ROM. If you want it to work first time.

Oh, OK. But how would a 512kB ROM work? This is the ST MF101.


I can see a spare pin (pin 30) for A17, but not one for A18, unless VPP is reappropriated and it's 5V only. Hmmm, close guess by me. This is the AMD 29F040:


It's the same except Pin 1 is A18 and Pin 30 is A17 and it's 5V only. Does the PCI board try to use Pin 1 as an address pin then?

Amazing levels of ignorance on my part, despite having programmed these things (I have a few SST 256kB Flash chips, but they're DIPs).

-cheers from Julz

 

[Phipli]

I think you're right! I saw they might be when I posted the photo.

Oh, OK. But how would a 512kB ROM work? This is the ST MF101.

View attachment 99228
I can see a spare pin (pin 30) for A17, but not one for A18, unless VPP is reappropriated and it's 5V only. Hmmm, close guess by me. This is the AMD 29F040:
View attachment 99229

It's the same except Pin 1 is A18 and Pin 30 is A17 and it's 5V only. Does the PCI board try to use Pin 1 as an address pin then?

Amazing levels of ignorance on my part, despite having programmed these things (I have a few SST 256kB Flash chips, but they're DIPs).

-cheers from Julz

They're designed to work with both. The pinouts are compatible - you never actually use the programming voltage in circuit so it is just wired for A18 in case you fit a 4Mbit chip.