Power Mac 6500 USB and ethernet cards

joevt · Dec 17, 2025

MacJunky said:
I've included some OpenFirmware dumps and System Profiler screenshots both pre and post bridge FW patch.

Unzipping "6500 Bridge FW Patch.zip" on modern macOS puts the resource fork in a separate file. The zip doesn't appear to include FinderInfo (it assumes all the FinderInfo exists in the resource fork)?
https://tinkerdifferent.com/threads/sit-create-stuffit-archives-on-unix-systems.4830/post-42185

The 6500 Bridge FW Patch doesn't help your Power Mac 6500 because it doesn't have the built-in ATI chip that is normally at device number @12 (slot F1). The patch works around a problem in the fcode for the built-in ATI chip by making that device/slot get probed last (therefore executing its fcode after executing the fcode for every other device).

MacJunky said:
Unfortunately my 6500 has decided it doesn't want to play nice with my Radeon 7000... again, so it's getting a timeout unless something is needed from OF directly. This is a long-standing on&off issue, pretty sure the 6500 is just a trash machine that isn't worthy of my time, but of course I don't have any other PCI machines to test the card in nor any other Mac-firmwared PCI cards that work in my 6500...

Your Radeon 7000 is at device number @E (slot B1).
What if you change the patch so that it gets probed last instead of device number @12?

Here's the patch:

Code:

dev pci1
defer ?p
a3b get-token drop to ?p
: ps
0d 17 -1 ?p
0e 19 -1 ?p
0f 1c -1 ?p
11 16 -1 ?p
12 18 -1 ?p
;
' probe-slots dup
284 + ' ps blpatch
dup 288 + swap 2FC + brpatch
unselect-dev

Change the order of the lines in :ps to change the probe order. For example:

Code:

0d 17 -1 ?p
0f 1c -1 ?p
11 16 -1 ?p
12 18 -1 ?p
0e 19 -1 ?p

MacJunky said:
And naturally the GF2MX doesn't work in Macs this old so I can't test with one of those.

If it's a 5V or universal PCI card with Open Firmware and an ndrv then it should work. What Macs is it supposed to work in? We could try updating the firmware. For example, we can make a 7800GT from a Quad G5 work in a Beige G3 or Power Mac 9600 with a PCIe to PCI bridge.
https://forums.macrumors.com/thread...l-work-in-a-beige-power-macintosh-g3.2303689/

Forrest · Dec 17, 2025

In my experience, USB1 cards made by NEC work well on PCI Macs based on the 6400/6500. The source of this info was on www.xlr8yourmac.com
I just learned this site closed down November, 2025 https://appleinsider.com/articles/25/11/05/xlr8yourmac-goes-offline-ending-an-era-of-diy-tinkering

MacJunky · Dec 17, 2025

joevt said:
Unzipping "6500 Bridge FW Patch.zip" on modern macOS puts the resource fork in a separate file. The zip doesn't appear to include FinderInfo (it assumes all the FinderInfo exists in the resource fork)?

I didn't create the file, this is how I downloaded it, not sure why it's a .zip, I didn't expand it on a non-old-Mac system. I included it for reference and/or if anyone wanted to compare the checksum against whatever was posted somewhere else. Stuffit doesn't like it, but MacZip 1.06 opens it in both Mac OS 8.6 and 9.1 on my 6500.

joevt said:
The 6500 Bridge FW Patch doesn't help your Power Mac 6500 because it doesn't have the built-in ATI chip that is normally at device number @12 (slot F1). The patch works around a problem in the fcode for the built-in ATI chip by making that device/slot get probed last (therefore executing its fcode after executing the fcode for every other device).

Unless I'm remembering incorrectly the patch didn't help before either, but I don't recall what cards got tested back then.
I've applied your recommended alteration and am still not seeing any positive changes with regard to the functionality of this particular USB card. I'm still seeing the same info in System Profiler with the same USB log errors and it still doesn't power up the mouse or ancient flash drive I was testing. I've also tried a very, very, old SanDisk ImageMate SDDR-31 CF card reader, an IBM Model M w/ USB adapter, and two powered USB hubs with no luck either. Perhaps another person with a similar modern USB card can add testing results as well in case mine is not functioning correctly.
Since changing the probing order I am getting display output from the Radeon 7000 again, whether or not that is related I don't know, in the past it will just decide when it feels like working and then be stubborn about it. But either way I'm glad to see it putting out video again.

joevt said:
If it's a 5V or universal PCI card with Open Firmware and an ndrv then it should work. What Macs is it supposed to work in? We could try updating the firmware. For example, we can make a 7800GT from a Quad G5 work in a Beige G3 or Power Mac 9600 with a PCIe to PCI bridge.
https://forums.macrumors.com/thread...l-work-in-a-beige-power-macintosh-g3.2303689/

PC GeForce MX ---> Mac GeForce MX

How to flash a PC Geforce to a Mac Geforce card

www.cybercoment.com

Supposedly New World machines are the requirement. And to be fair I'm not 100% certain that my ebay-sourced card is even working properly in a PC, or compatible with the Mac ROM in the first place, but I'm sure that's a different issue for a different thread. Either way I put a socket on it so it's ready for action.

As a side note, my NEC USB card seems to have a blank 24C02 on it. Not sure what that was for, but it's there. Kinda wish I had something else to test these cards in as I also have a manually flashed SiI3112 that needs verification... Not that I had troubles socketing and flashing SATA cards in the past, but I was also using them in different(and superior) machines.

Forrest said:
In my experience, USB1 cards made by NEC work well on PCI Macs based on the 6400/6500.

Indeed, there are cards with the same chip that Apple used in their early USB systems which work seamlessly.

indibil · Dec 17, 2025

Hello. I've done some more testing.

First, I added a battery because without it, every time I unplug it, the PRAM is erased and the patch is lost.

I tried three PCI cards that I have, which work perfectly in my G3/G4 processors.

None of them worked in the 6500, and the Sonnet Tango froze on startup. That's when I looked at the Sonnet box, and it said it was compatible with the 6500, and the instructions said the Sonnet included a patcher for it to work. I looked for it, and after resetting the PRAM to remove the previous patch, I installed the Tango, applied the patch, and restarted, but it still doesn't work. The LED only lights up for a fraction of a second when I connect a mouse, and then it goes out.

https://www.macintoshrepository.org/17234-sonnet-tango-tempo-firmware-update-version-1-3-

It's all very strange.

Forrest · Dec 17, 2025

I'm very surprised the Sonnet card didn't work.

Are there any signs of capacitor leakage on the 6500 logic board?

nathall · Dec 18, 2025

MacJunky said:
Perhaps someone knows how to decipher the errors in the System Profiler's USB log window?

As a side note I was observing the same issues under Mac OS 8.6, you can see the collections of extensions I had been trying at the time.
View attachment 93351 View attachment 93350 View attachment 93354

I had the exact same set of errors on my 8500/G3 with the OrangeMicro/NEC card I was trying to get to work under 9 in the thread I linked to earlier. I tried all combinations of the MacOS USB extensions.

One thing I didn’t mention... I have a USB1 PCI card that works fine under OS 8/9. The OM/NEC is USB2. Was yours USB2 also?

Phipli · Dec 18, 2025

Come on folks, this is a really common issue. Just reinstall the OS, customise the install and make sure you check the PCI USB option.

Having some USB stuff installed doesn't mean you have the right usb stuff installed.

USB 2 NEC cards work fine as 1.1 cards in classic Mac OS.

MacJunky · Dec 18, 2025

That hasn't worked for me on this particular machine. In general, yes, I agree and used to use an older NEC USB 2.0 card in my G3 and G4 systems running OS 9/X of the time.

I just ran a fresh install on my 6500, clicked customize, and found that the installer had pre-selected 'USB Adapter Card Support' but not 'USB'. So I ran it as presented and USB devices weren't showing up. Then I ran the installer again and manually selected 'USB' and 'USB Adapter Card Support'. Still not working.
For the sake of curiosity I ran the installer a couple more times, and according to the Installer Log these are the extensions installed with just USB selected:

Code:

“Apple Enet DLPI Support”
“EnetShimLib”
“HID Library”
“SerialShimLib”
“USB Device Extension”
“USB Software Locator”
“USBAppleMonitorModule”

And with only the Adapter card support package selected:

Code:

“Apple Enet DLPI Support”
“EnetShimLib”
“HID Library”
“SerialShimLib”
“USB Device Extension”
“USB Mass Storage Support”
“USB Software Locator”
“USB Support”
“USBAppleMonitorModule”

So obviously both don't need to be selected. Somehow I think I had read this somewhere a long time ago but don't recall. Anyway..

I'm curious to know if other people who have these NEC cards with specifically the newer D720101 chips are having success in old-world machines, and/or the 5500/6500/TAM, or if their success is with the older D720100A chips.
Or did I just miss an extension somewhere? Just for fun I am currently running a full install with everything selected, I'll post about it if it works.

indibil · Dec 18, 2025

Forrest said:
I'm very surprised the Sonnet card didn't work.

Are there any signs of capacitor leakage on the 6500 logic board?

Hi, after reading your reply, I decided to try it. First, I recapped the PSU. Although the capacitors weren't showing any problems with the checker, I replaced them. Nothing changed.

Then I replaced some capacitors near the PCI slot (I didn't have more time today) and it's still the same. I made a couple of videos of the behavior, but nothing changed. I'm using the Sonnet Tango to be sure.

Just one thing: before, the first time I pressed the power button, I heard the chime but the LED didn't light up and it wouldn't boot. Then I would turn it off and on again and it would work. Now it works on the first try.

Tomorrow, if I have some time, I'll continue replacing capacitors, although I'm not sure that will solve the problem. I'm using tantalum capacitors because I don't have the exact same ones as the originals.

View attachment VID_20251218_180222-converted.mp4

View attachment VID_20251218_180612-converted.mp4

Forrest · Dec 19, 2025

Sounds like replacing the capacitors is working. Great job.

indibil · Dec 20, 2025

Forrest said:
Sounds like replacing the capacitors is working. Great job.

I've finally finished the recap and it's still the same, nothing has improved. I can't imagine what the problem could be. Even the Sonnet Tango isn't working.

nathall · Monday at 6:17 AM

MacJunky said:
That hasn't worked for me on this particular machine. In general, yes, I agree and used to use an older NEC USB 2.0 card in my G3 and G4 systems running OS 9/X of the time.

I just ran a fresh install on my 6500, clicked customize, and found that the installer had pre-selected 'USB Adapter Card Support' but not 'USB'. So I ran it as presented and USB devices weren't showing up. Then I ran the installer again and manually selected 'USB' and 'USB Adapter Card Support'. Still not working.

Phipli said:
Come on folks, this is a really common issue. Just reinstall the OS, customise the install and make sure you check the PCI USB option.

Having some USB stuff installed doesn't mean you have the right usb stuff installed.

USB 2 NEC cards work fine as 1.1 cards in classic Mac OS.

Yeah, as MacJunky indicated, this doesn’t work. And like him, my 9.1 install disc doesn’t have a “PCI USB“ option. Only USB and USB Adapter Support.

I know I’ve tried this before, but for the sake of this thread, I tried again just now onto an empty RAM disk with nothing else on it. Results are the same. My machine is an 8500 and not a 6500, for the record.

MacJunky said:
I'm curious to know if other people who have these NEC cards with specifically the newer D720101 chips are having success in old-world machines, and/or the 5500/6500/TAM, or if their success is with the older D720100A chips.
Or did I just miss an extension somewhere? Just for fun I am currently running a full install with everything selected, I'll post about it if it works.

I don’t think it will... I tried it before with no change.

Not sure what revision of the NEC chip mine has. I’m hesitant to open up the 8500 to look because of the brittleness of the plastics, but next time I’m in there I’ll look.

croissantking · Monday at 1:27 PM

nathall said:
USB Adapter Support

This is what @Phipli meant when he said PCI USB Option.

Power Mac 6500 USB and ethernet cards

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