View Full Version : 8500 is a 7500???

02-20-2001, 12:58 AM
Is there any reason Apple System Profiler reports that my 8500 is a 7500/7600 model?

8500/150 w/Sonnet G4/450 (formerly Newer G3/300)
384 mb ram, OS 9.04.

I've noticed this through both CPU upgrades--however my 7500 with the Newer card still says it's a 7500. Any thoughts?

02-20-2001, 02:00 AM
ASP reads the ROM. I've never looked at 8500, but I should think it would read "8500" unless the ROM has been changed. Some 8500's had removeable ROM modules and some had empty ROM slots and the ROM was soldered on the logic board. Are you the original owner?

ASP on a UMAX S900 says it's an 8500. ASP on a Power Tower Pro says it's a 9500.

02-20-2001, 02:28 AM
I think that ASP looks at something in addition to the ROM to determine the model though. The reason that I suspect that is that the Apple Part numbers on the ROMs in my Umax S900 are exactly the same as the Apple part numbers on the ROMs in my 7500. I may be overgeneralizing, but I believe that the ROM in the 7500, 8500, 9500, S900/J700 and PTP/PW are all the same with perhaps a couple of different revs. available.

The S900 used to be reported as a 9500 in the ASP then it changed to an 8500 and someone told me it's showing up as a 9500 again with 9.1, but I haven't checked that one out myself yet. Anyway, if ASP changes what kind of machine it sees from OS to OS, I suspect that means it is looking for somethign in addition to the ROMs.

The 8500 motherboard is actually the same circuit board as the 7500 with the same components soldered on. The difference is that the 8500 has a couple of extra chips installed to support the video out functionality. On the 7500 one can see the blank spaces where the chips would be if the board were an 8500 instead of a 7500. That's why there is a speaker plug at both ends of the board. In a 7500 the left side plug is used. In an 8500 the right side (top edge in 8500) is used. This saved Apple the money of manufacturing two different circuit boards.

However, I don't know why ASP would report an 8500 as a 7500. It should be smart enough to check for the extra video circuitry and tell the difference, I would think. Hmmm. Are you using the on-board monitor port or a PCI card? If you are using a PCI card with no monitor attached to the on-board video, the on-board video doesn't get activated and maybe that keeps ASP from telling the difference. That's a WAG, not necessarily correct.

02-20-2001, 03:57 AM
This is the same problem I saw after changing a 7500 with an 8500 board.

I had thought that maybe the id was only checked during system installation, and that if I reinstalled, it would read as an 8500. After reading this, it's apparent that is not the case.

I'm at a loss. FWIW, I had a monitor using logic board video.

[This message has been edited by despaxas (edited 20 February 2001).]

02-20-2001, 09:32 AM
Come to think of it...I'm using a TT128 PCI card swipped from a SuperMac clone. Could this combo be "fooling" my 8500 into thinking it was something else? Not a big deal (could always use 'wish I were' to change) but just curious.

02-20-2001, 09:37 AM
BTW--I am the original owner and there is an empty ROM slot on the motherboard. Also ASP-Active enabler reports: PowerPC enabler 9.04 9.04 (double). I though this was strange as well. I have not see this on other macs.

02-20-2001, 03:07 PM

Speaking of ROM modules having the same Apple part number; I noticed that with the beige G3 ROMs. There are three different ROM subversions 4.0F2 (Rev A), 4.5F1 (Rev B) and 4.5F2 (Rev B also) (There is no Rev C), all with the same p/n on the board.

ASP reads machine ID from somewhere. My PTP is ID 67 which is the same as the 9500.

02-20-2001, 05:49 PM
Louie, that is strange about the G3 ROMs. When you say the P/N on the board, is that a part number on the DIMM(?) that the ROMs are soldered to, or is that a part number on the actual ROM chips?

I was working on the assumption that chips which have the same part number embossed on them would have the same logic inside. But your G3 example may shatter than assumption.

02-20-2001, 06:42 PM
It was the DIMM. I see your point. Next time I get at one I'll look at the other numbers.

02-20-2001, 08:34 PM
Hey trag,

How did you find out about that second speaker connection on the 8500 mobo? I have wondered about that for years and some folks have asked about it on the forum but I could't find anything on the subject. In the serpentine labyrinths of my own imagination, I had figured that it was an unused channel for an original stereo circuit plan for the internal speaker system.

02-20-2001, 11:39 PM
trag is just a very, very smart Guru.


nice thread, gentlemen.


02-21-2001, 11:39 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>How did you find out about that second speaker connection on the 8500 mobo?<HR></BLOCKQUOTE>

I just put pieces together that I accumulated over the years. Most of the stuff I don't remember where I read, though much of it was probably from MacUser and MacWorld back when they actually published useful hardware articles (well, and when MacUser was still alive). I'd heard that 7500 and 8500 boards fit in each others' cases. That they were nearly identical, etc. I have an 8100 in the house which has a similar case style to the 8500.

Then I got a 7500 and examined the board. Oh, and read some info in Apple's Tech Info Developer's Library about the architechure of the boards. That makes it pretty clear that the boards are identical except for the video out circuitry. You can see the places for that on the 7500 board. Then if you're looking at a 7500 board sitting in its case with the extra speaker connector on the right and you're familiar with an 8100 (or more relevant, an 8500) you can see that the extra speaker connector would be right where it needs to be in the Apple tower style case.

Looking at the different motherboard and case designs you can see the progression of engineering. The early PCI Macs (x500) really aren't that different from the NuBus PowerMacs (x100). Sure there were a lot of improvements, and the chipsets are different, but for each chip on a NuBus PowerMac there is a corresponding chip on an x500 PowerMac which is different but serves the same function.

The Curio chip from AMD which provides slow external SCSI and ethernet (and I think serial ports) is even the same chip on the two families. And the motherboard video chip on the 7500 appears to be only slightly different from the video chip you'll find on the HPV card for the NuBus PowerMacs.

Case designs follow family lines too. The excellent 7500 case grew out of the old IIcx case. It mutated through the IIvx (Q650, 7100) case on the way, but you can see the similarity in design. And their tower cases went through a similar evolution. Engineering works like that.

02-21-2001, 05:59 PM
Any thoughts on the enabler reporting 9.04 9.04 or is my mac posessed?

02-21-2001, 06:43 PM
My 9600's and my 7500 all reported similar things. With 9.1 all is fixed. I never noticed 9.1 fixed it til now. Thanks for the making-me-look!!

02-22-2001, 12:12 AM
Not quite ready for 9.1 yet. Inital install created numerous problems with Photoshop 6 crashing while performing image manipulations. Had to go back to 9.04.

02-22-2001, 12:36 AM
Hey trag,

Thanx for sharing http://macgurus.com/infopop/emoticons/icon_smile.gif