68kMLA Classic Interface

This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.

Click here to select a new forum.
Getting G3 Whisper Perch USB working
Posted by: Phipli on 2023-10-07 01:49:35 does the "Bordeaux" personality-card (the one with a DVD-Video compatible MPEG2 decoder-chip onboard) also have the solder-pads and headers for a USB-port? It does. There are more than one version of each of the three card types, at least seven total I think. So the answer is more "some do".
Posted by: croissantking on 2023-10-07 01:52:23 There are more than one version of each of the three card types, at least seven total I think. So the answer is more "some do". From the photos I’ve seen of the Bordeaux, there is only one revision. This would make sense if it came out a bit later in the lifecycle of the Beige G3 - I don’t think the DVD option was available at release.
Posted by: Phipli on 2023-10-07 02:06:08 From the photos I’ve seen of the Bordeaux, there is only one revision. This would make sense if it came out a bit later in the lifecycle of the Beige G3 - I don’t think the DVD option was available at release. I can only see pictures of a small number of them online, so I wouldn't want to conclude that any could be modified. They're pretty rare.
Posted by: StevieC on 2024-06-14 09:16:05 The ability to get this USB port working on the Personality Card implies that there at least some amount of PCI functionality in the PERCH slot, which makes me wonder if it would have been possible for Apple to have made the modem slot on it a full Comm Slot II and retained compatibility for Comm Slot II EtherNet cards
Posted by: croissantking on 2024-06-14 11:23:16 The ability to get this USB port working on the Personality Card implies that there at least some amount of PCI functionality in the PERCH slot, which makes me wonder if it would have been possible for Apple to have made the modem slot on it a full Comm Slot II and retained compatibility for Comm Slot II EtherNet cards It probably would have been possible indeed.
Posted by: StevieC on 2024-06-17 14:55:06 Then we were robbed. Had Apple preserved full Comm Slot 2 functionality in the slot on personality-cards for the Beige G3, we could've had 100 Mbps EtherNet without needing to use up one of the 3 PCI slots
Posted by: croissantking on 2024-06-17 16:02:18 But with USB on the Personality card, you don't need a USB PCI card 🙂
Posted by: StevieC on 2024-06-19 23:02:26 What I'd love to see is for someone to get the USB port on a Molar but have it be internal and then install the kit that ēlo offered for the iMac G3 to make its CRT a touch-screen, but onto the Molar G3's CRT
Posted by: croissantking on 2024-07-03 12:43:25 I'm delighted to announce that I've got the Opti Firelink 82c861 chip working with the Personality card. We no longer need to source the scarce CMD 0670 chips. I compared the USB logs of the working 0670 chip and troublesome Firelink chip in Apple System Profiler. The error in the Firelink's log window was 'OverCurrent Indicator Change detected' after which the chip would just hang, and fail to complete initialisation. Looking at the datasheet for the Firelink, PWRFLT1 and 2 are responsible for indicating that an over-current fault has occured on each of the USB ports. It also says 'their polarity can be software controlled: strap low for active high, strap high for active low.' On my design, PWRFLT2 is tied high through a 10K resistor, since there is no second USB port, but PWRFLT1 is left floating. I decided to try tieing it high, which required a bit of a bodge to do: Like this, it works. I can plug in a USB device and it's recognised and works perfectly. So, to sum up: PWRFLT1 is used to indicate to the USB chip, by use of an optional glue logic chip at U9, that an overcurrent fault has occured. This feature is redundant if using a fuse to supply power, which in the current design we do. The 0670 chip does not care if this line is left floating, but the 82c861 errors out. Solution, tie it to +5V with a 10K resistor.
Posted by: just.in.time on 2024-07-03 20:05:20 @croissantking very cool find!
Posted by: croissantking on 2024-07-04 03:53:53 @croissantking very cool find! Are you going to mod yours now?
Posted by: croissantking on 2024-07-04 05:31:58 I played around more with the Firelink equipped card last night, trying a bunch of different devices and it’s all running great. I’m currently working to populate a Wings card that @blitter sent me. Once that’s done I’ll upload new schematics and a BOM for it.
Posted by: trag on 2024-07-04 21:21:35 I'm guessing that Firelink chip comes in both a square and a rectangular package? Square Firelink 82C861
Posted by: falecore on 2024-07-05 00:59:37 Really cool, I am surprised nobody has figured this out already. Lack of onboard USB has always been a frustration, if you wanted better video, 10/100 Ethernet and faster SCSI you had to give up USB... or keep USB and give up 10/100 ethernet... or a SATA card and give up something else. Always give and take!! Wish the G3s had four PCI slots. Someone showed this to me at VCF east two years ago. Very cool!
Posted by: croissantking on 2024-07-05 02:27:25 I'm guessing that Firelink chip comes in both a square and a rectangular package? Square Firelink 82C861 Yes, I’ve never seen the square one in the wild though. Someone showed this to me at VCF east two years ago. Very cool! Could have been me? Although you say two years ago... But I was there in 2023 and I brought the Personality card.
Posted by: croissantking on 2024-07-08 09:56:38 Project update, I’ve been trying to get the UCC3912 chip to work with the 0670. So far, no luck - I get an error saying that the built-in USB port is drawing too much power and will be disabled. So this will require some further investigation. A curious thing is that the CMD0670 datasheet, which I’ve based my own schematics on, shows D1 pointing towards PWRON1 (on the 0670) but the silkscreen on the Apple PCB shows it pointing towards SHTDWN (on the 3912).
Posted by: croissantking on 2024-07-08 11:59:09 I've been looking at the startup circuit, as well. Transistor Q9 on the personality card goes to the CUDA chip pin 24 on the logic board. This pin is at 5V when the PSU is connected. Pulling it to ground starts up the machine. So this is what Q9 needs to do. I've traced Q7 as going to U32 pin 14 on the logic board which is just VDD.
Posted by: croissantking on 2024-07-08 13:28:19 I suddenly got excited and traced out the startup circuit on my G4 Yikes! logic board. It's almost identical to the one on the Personality card. I think we're close to getting this working 😃 I will measure the transistors on my component tester - unless the markings (1AM, P2A) already give us enough information about what they are. U11 on the G4 logic board is a LM393 Dual Comparator. This is certainly what goes at U1 on the Personality card, but – and maybe I'm looking at this wrong – it seems like a LM393 doesn't fit the footprint.
Posted by: croissantking on 2024-07-08 16:40:03 Latest update to the startup circuit. Red values I'm certain about, blue ones are a best guess. I'll be getting an iMac 233 logic board shortly, courtesy of one of our members, which will be interesting to look at and see if it does things any differently than the G4. This is a very entertaining jigsaw puzzle.
Posted by: dougg3 on 2024-07-20 19:58:35 I've been silently following this thread ever since the beginning and very much enjoyed it! Really nice work! I somehow just today discovered that for the past decade, I've had a Beige G3 Desktop that came from the factory with a DVD drive, and indeed it has a Bordeaux card inside. With the knowledge that I actually have one here in front of me and I also have a multimeter and know how to use it, is there anything I can do on my end to help complete your notes so we have a BOM for adding the USB ports to Bordeaux cards? Is it rare enough that it would be a sin to modify it? 😀
< 16 >