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Power Mac 9600 - 350Mhz CPU Card Issues

KGLlewellyn

Active member
Hey all,

I've recently picked up a Power Mac 9600/350, unfortunately its CPU card is unwell. I know the machine is good as it works fine with the Sonnet G3 233Mhz card I picked out of my 7600. However, when the 350Mhz 604 card is installed, it'll just chime and the monitor will stay dark. It's labelled as the Macintosh High Performance Processor Card 100, with the resistor on the 350Mhz solder points.

Has anyone been able to repair one of these, or do you think it's perma-toast?
 

macuserman

Well-known member
Have you tried wiggling the card side to side and checking to see if reseting the pram after that gets it to boot? I've found that the cards have different thicknesses sometimes they don't want to play nice after you swap them around like that.
 

KGLlewellyn

Active member
Yup, I've tried that. No go sadly, also used some deoxit on the contacts and the slot.

One thing of note the first time using it, the startup chime sounded pretty garbled with static, but thereafter it sounded fine, but still nothing on the screen. I hooked up a serial cable to see if it was dropping into OF, but it appears that it isn't. I've ordered a 300Mhz card which appears identical to the 350Mhz one, and I'm going to see if I can use it to help troubleshoot the 350Mhz one.

Ofc if someone has info on modifying the 300Mhz one for 350Mhz then that'd be uber helpful. As far as I know, putting the resistor on the 350Mhz solder points isn't sufficient, that only impacts how the card reports to OF and the OS. Thanks!
 

Powerbase

Well-known member
I take it youve confirmed it's a Mach V motherboard and not an older one someone swapped in.

Im not sure what the older boards did when you tried to run a Mach V card in them.
 

KGLlewellyn

Active member
The machine is badged as a 9600/350 and the card is branded as a Mach V and the computer identifies itself as a 9600 with a G3 card in it. I'm not at home right now to double check the board. I'll report back on that.

I will say, it may be an early 9600 board as it doesn't have soldered ROMs on the board and instead has a ROMsimm installed.

Actually here's a bit of the board from the original eBay listing, not sure if you can determine it's a Mach V from that? Part No is ..20-0939-03 guessing by the pic?

Seems to be this one https://commons.wikimedia.org/wiki/...sh_9600_logic_board_820-0865-A_(661-1221).jpg (Board Copyright Date 1997)

The other variant appears to have a 1996 copyright date and has the square IC's on. https://commons.wikimedia.org/wiki/...20-0865-A_Power_Mac_9600_Motherboard-0928.jpg (I presume this is the non-Mach V board?)
 

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Franklinstein

Well-known member
The 9600/350 was indeed factory-equipped with the 604ev Mach 5 (unless yours has had a logic board swap at some point). It was the early run <300MHz ones that may not play nice with a Mach 5 card because they weren't qualified to run it. I'm not entirely sure what differences exist between the logic boards but there must be something, at the very least possibly a higher-wattage power supply, to support the faster CPU and its high-speed inline cache.

The 9600 is also getting a bit old so it could be something capacitor-related such as not giving the 604 card as much power as it wants, causing the instability. The G3 cards use markedly less power than the 604 cards so something that may be marginal running a 604 may be fine with a G3 card.
 

jeremywork

Well-known member
The machine is badged as a 9600/350 and the card is branded as a Mach V and the computer identifies itself as a 9600 with a G3 card in it. I'm not at home right now to double check the board. I'll report back on that.

I will say, it may be an early 9600 board as it doesn't have soldered ROMs on the board and instead has a ROMsimm installed.

Actually here's a bit of the board from the original eBay listing, not sure if you can determine it's a Mach V from that? Part No is ..20-0939-03 guessing by the pic?

Seems to be this one https://commons.wikimedia.org/wiki/...sh_9600_logic_board_820-0865-A_(661-1221).jpg (Board Copyright Date 1997)

The other variant appears to have a 1996 copyright date and has the square IC's on. https://commons.wikimedia.org/wiki/...20-0865-A_Power_Mac_9600_Motherboard-0928.jpg (I presume this is the non-Mach V board?)
The board in the auction photo is a Kansas board, correct for a Mach V CPU. The four plus two unpopulated sets of pads oriented vertically are for motherboard cache, only populated on 604e Tsunami boards. The four horizontally oriented sets of pads are indeed for ROMs. There are some comparison pictures on the page below.

 

KGLlewellyn

Active member
The board in the auction photo is a Kansas board, correct for a Mach V CPU. The four plus two unpopulated sets of pads oriented vertically are for motherboard cache, only populated on 604e Tsunami boards. The four horizontally oriented sets of pads are indeed for ROMs. There are some comparison pictures on the page below.

Sweet, thanks for confirming that! At least we know the CPU card is compatible. :) And thanks for the link, that guide was a very interesting read.
 
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KGLlewellyn

Active member
Okay, I'm back from my vacation and installed a 300Mhz card I got from eBay which appears to work. So I guess my original card is toast, and 350Mhz replacements don't seem to easy to get. Does anyone know the process of modifying a 300Mhz to 350? From what I've heard it appears possible?
 

jeremywork

Well-known member
Glad to hear your system works with the 300MHz CPU. I've heard of at least a few 350 boards clocked to 450-500MHz with some success, so a 50MHz overclock on the 300 seems pretty safe.
 

Franklinstein

Well-known member
The board in the auction photo is a Kansas board, correct for a Mach V CPU. The four plus two unpopulated sets of pads oriented vertically are for motherboard cache, only populated on 604e Tsunami boards. The four horizontally oriented sets of pads are indeed for ROMs. There are some comparison pictures on the page below.

That link isn't entirely a bad read but I think they have a few bits incorrect regarding CPU caches:
Cache hierarchies generally go with the ones closest to the processor first and work their way out, not weaving around as described on that thread. So the CPU's L1 cache is of course first (since it's internal to the processor), then the first external cache (which on a 750 or 7400 is backside and directly processor-controlled) would be L2, and then if present and enabled the bus-level cache would be L3. Of course if you don't have extensions configured correctly, this can cause the CPU's backside L2 to be ignored in which case the bus-level cache would become the L2 cache.
Anyway the reason the 604ev Mach 5 has no bus-level cache on the logic board is that it already has a bus-level cache on its High-Performance Processor Card module and so couldn't make use of the logic board's cache even if it was installed. Removing the logic board cache on the Kansas models was done to prevent system conflict in trying to manage two separate bus-level caches (and also to reduce cost; SRAMs are expensive). Also just because it's present doesn't mean it has to be used; it's easy to disable and there's nothing that causes the logic board's cache to "have all of your CPU juice running though a slow 512k L2 cache at all times."

Side note: the 60x bus is kind of funny: it can either directly support one CPU and a bus-level L2 cache, or up to 4 SMP processors with no bus-level cache. Daystar was somehow able to get around this with the MP cards that they developed for their own use and licensed to Apple for the 9500/180MP and 9600/200MP (I'd really enjoy reading the technical details here if anybody has them). Daystar also helped develop the High-Performance Processor Card for the 9600, if you didn't know. Anyway the reason the G4 Macs could use SMP with large L2 caches is that the caches are CPU backside-type, not bus-level, so the bus doesn't have to control the cache and therefore it can control multiple processors instead.
 
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