550MHz G4 PowerBook (Pismo vs Titanium)

[herd]

A 7448 should work fine (or better) anywhere that a 7447 can, but I don't know where to get them. New 7447 chips are for sale on ebay.

Amazingly, documents like this are available, even today:

www.nxp.com/docs/en/application-note/AN1812.pdf

In there you can see that pin-compatible chips are not necessarily interchangeable. The Pismo is the only G3 machine I have for testing, and it seems to be a transitional example because it has correct configuration connections in place to easily take a G3 or G4 in 60x or MPX bus mode. I would guess that earlier G3's potentially have more problems. I think a 7447 working in a G3 machine that can be tested in either bus mode would be a step towards upgrading earlier versions that did not already anticipate G4 chips.

Your idea about putting a G3 into a Gigabit Ethernet might be another way to test things. I suspect it would work and firmware patchers exist for these machines. So testing a 7447 in 60x mode installed on 7400 pads in a Gigabit Ethernet could show the feasibility of doing something similar for earlier machines.

 

[joshc]

If the titanium is basically a Pismo why is it so much more unreliable and problematic?

 

[GRudolf94]

If the titanium is basically a Pismo why is it so much more unreliable and problematic?

Are they? The only logic-related fault I'm aware of on Titaniums is, on 867/1000s, the L3 failing - and that happens to AlBooks as well, so...

Construction is crappy, but so is the Pismo's.

 

[s_pupp]

Are they? The only logic-related fault I'm aware of on Titaniums is, on 867/1000s, the L3 failing - and that happens to AlBooks as well, so...

Construction is crappy, but so is the Pismo's.

If the titanium is basically a Pismo why is it so much more unreliable and problematic?

I have half a dozen of each of the four generations of TiBooks. They are all largely problem free, except for five of the six second generation TiBooks (VGA+gigabit, 550 and 667MHz).

In addition to the terrible appearance from 3/4 of the paint flaking off the frame, they either won’t boot reliably (or at all), or crash so frequently as to be unusable.

I don’t know what cost-cutting measures led to such an awful generation, but they seemed to have sorted them out for the next two.

 

[GRudolf94]

In addition to the terrible appearance from 3/4 of the paint flaking off the frame, they either won’t boot reliably (or at all), or crash so frequently as to be unusable.

All of mine (400, 550, 867, 1000) have bad paint. The 400 and 550 have bad hinges and bad polarizer too, are in pieces and might end up scrapped. The 1000 has bad L3. That said, they all boot fine.

 

[herd]

I think some of the reported L3 issues are firmware or power-saving related. Maybe some of the firmware experts could figure out the details of what it's doing, but I think the later Titaniums would turn off L3 when on battery, or when in "reduced" performance mode. The CPU speed and voltage could also change on the fly (and this was before DFS). I read one account where you had to have a good battery and external power plugged in to get full speed from the machine.

I've also read that Sonnet did 7457 upgrades on these, so running their patcher might sort out some of the firmware weirdness on stock computers too? Or maybe their firmware mods for the upgrade were only available in-house...