From: [EMAIL PROTECTED] Date: Sun, 17 Apr 2005 17:46:57 EDT
The 9150 is a beautiful machine too. Anyway, dont throw out the 16MB SIMMs,
there are plenty of people who will pay for them, myself included. I only
have 8 of them, and I also have a Mac II so Id take all 16. Anyway, Id like a
JPEG of the drive sled too. If possible, Id like a high resolution JPEG of the
100MHz card. I want to compare it to my 80MHz card too see the differences.
I was thinking of paying somebody to solder on a 120MHz 601 to my 80MHz
PowerPro with RAM expansion (anyone know how much this would cost???), obviously
some things need to be reworked. But a 120MHz (or slightly faster) Quadra 950
with perhaps 512MB RAM would be sexy (at least 384MB RAM).
Well, you're not going to get more than 256 MB into the Q950 without something like a Daystar RAMCard (are those Q compatible?). Sixteen sockets times 16 MB per stick is 256 MB of RAM, maximum theoretical capacity.
In the case of the Turbo601 (the PPC upgrade for the IIci, IIsi, IIvi, IIvx), it was necessary to move a couple of handfuls of resistors and add an ICS9178 chip in order to speed up the 66 MHz version to close to 100 MHz. The ICS9178 is no longer available but there might be something with the same functionality and pin compatible available from ICS.
The ICS9178 may also be found on PM8100 (and clones) boards which are 100 MHz or faster.
The PPC601 is a 304 pin chip with a very fine pin pitch. I think it would cost you less to just find a faster upgrade card for sale, than it would cost to obtain a faster PPC601 chip and have it soldered in place.
There is also the issue that the > 100 MHz PPC601s use 3.3V supply while the slower <= 80MHz use 5V. The LT1085 voltage regulator which was commonly used on PPC601 cards can be adjusted to provide 3.3V instead of 5V by changing a couple of resistors, but it is another change that would be needed. And I'm not certain that would take care of issues with the I/O voltages. On the 8100 and clones which are 100 MHz or faster, there are a series of 3.3V to 5V buffers around the PPC601 chip to switch the bus signal voltages between 3.3V for the PPC601 and 5V for the rest of the computer.
On the Turbo601 card, I was able to get 96 MHz out of the 66 MHz rated PPC601 after adding the ICS9178 so that the card clock tripled instead of clock doubling. If you Google up Marc Schrier's Clock Chipping Home Page you can read the article I wrote about it (9 years ago?). I don't have the URL handy at the moment.
I think you would also find that the PPC601/120 is nearly impossible to find, and if you do find one from a parts supplier, it is likely to cost close to $100. However, you might be able to salvage one from a 7200/120 or a CPU card for the PowerCurve (PCC predecessor to the PowerCenter), which used a 120 MHz PPC601). But that would mean a successful desoldering job as well as a resoldering job.
Anyway, it's a worthy project to try upping the speed of the 80 MHz upgrade, but I think that replacing the CPU chip is too ambitious. You should first focus on whether the slower card can be modified so that the PPC601 clock triples instead of clock doubles.
Jeff Walther
-- Quadlist is sponsored by <http://lowendmac.com/> and...
Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! |
Support Low End Mac <http://lowendmac.com/lists/support.html>
Quadlist info: <http://lowendmac.com/lists/quadlist.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[email protected]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/quadlist%40mail.maclaunch.com/>
iPod Accessories for Less at 1-800-iPOD.COM Fast Delivery, Low Price, Good Deal www.1800ipod.com
