CC Upgraded with a 6500 board - a few questions

before I ripped my takky apart a few days ago to try the lc575 a/b upgrade (thus, when I had a FUNCTIONAL takky), I was running 9.1 without any problems at all... bear in mind I also have a 350mhz g3 upgrade card, so it might not be quite as snappy for you.

I was lucky, though, when I originally started my project... a friend of mine had given me a mini-atx power supply, so I didn't have to worry about where to get the 3.3v... I had it from the get-go. I have a feeling a lot of the quirks you may be encountering might be due to the lack of a 3.3v source.

As far as the sound problems, I wouldn't know what to say... I didn't have any room inside my machine for the internal speaker, so I had to rely on external ones. I don't have any hissing though.. just make sure all connections are good?

And same goes for the SCSI problem... maybe there's a termination problem somewhere... when I first modified the motherboard connector (out of a donor 5200), I accidentally managed to DESTROY all the pins for a scsi cable on the connector (the "A1" through "A50" pins)... so... I just use IDE with a laptop hard drive ¬.¬ All the same, I don't have any room inside for a SCSI device anyway.

I also have a CSII ethernet card, and occasionally have problems with it even inside the 6500 tower chassis... I think, in my case, it's due to the fact that the card is relatively loose in it's slot... like, the design wasn't very secure, so sometimes I just have to wiggle it a bit and restart.

I'm just rambling, sorry I don't have any powerful insight or wisdom to offer... just my own experiences ._.

I have 9.2.2 on my Takky/225Mhz with maxed RAM. I used to use a CSII ethernet card just fine, but I switched to a PCI 10/100bT card, which is also fine. I don't have any sound hissing problems, but I also don't have an internal speaker. Sounds like you've got some kind of inductance problem. Connecting the ground planes of everything together sounds like a resonable starting point for removing the hiss.

MacOS 9.2.2 works just fine. It's a little slow, but I think that's more becaue of the laptop-style hard drive I have in it on the internal IDE bus.

My Takky has the whole 2-slot PCI frame from the 6500 inside. I've got a 256k L2 Cache, max RAM, video-input card, and a PCI network card. I used to have a CS-II network card and a USB PCI card, but those have been removed. I have an internal SCSI Zip drive and a 2.5" IDE drive to boot from. I'm using the LC575 Analogue board. It seems like our Takkys are pretty similar except that you've got a SCSI hard drive.

What kind of hard drive are you using? I'd guess you might be taxing the power output ability of even the LC575 board with some kind of power-sucking hard drive. Try switching to a laptop-style tiny drive and see if that helps. The x500-series boards make their own 3.3v from 5v(IIRC), so if you're taxing the 5v supply from the analogue card, you'll cause yourself 3.3v-problems, too.

Simply adding an external 3.3v regulator would probably help, too. I think I'll have to add one myself, when the time comes to put a G3 into this machine.

Ideally get a 3.3v line installed, or at least an additional 5v supply, before trying other strategies. Good luck!

Stuart

I've considered installing a new / additional power supply, actually. But in order to do that, I'd love to know what kind of PSU you've used and how you installed it. I would probably mount my laptop drive (if I'd ever get the IDE interface to work) somewhere inside the case, as it is quite a bit smaller than the SCSI drive that I'm currently using, freeing up the 3.5" HD bay for i.e. a PSU. Did you connect the input leads to the CC AC inputs or do you have a separate cable running out of the system. Again, how did you do it? I've also seen i.e. Micro-ITX PSU's which are significanly smaller than the standard ATX form factor and use DC voltage input and regulate it to the 3.3v, 5v, and 12v required for the system... This is probably the most difficult step in finishing up my Takky project.

Regarding the hard drive. I'm not quite sure off the top of my head what the 'precise' serial number is, but it's an IBM DGHS (not sure about the latter) 4.3 GB SCSI drive. The interesting thing is that I've installed the device into an external enclosure and hooked it up to the SCSI bus, still, when using the cache card, the system won't initialize the display. So I don't think it's the drive that actually sucks the PSU dry - heh.

Mini-ITX is what you're thinking of there. I've seen ones that are nothing more than a small circuit board that plugs straight onto the ATX power connector on the mobo, and as you say rely on an external DC supply to do the grunt work. It's never occured to me before, but these would be ideal for a CC if you could live with the external PS - gets you more space and less heat inside.

Hmm, maybe with a beefy enough internal PS (5500?) to run the analog side, there would be enough 12V juice left over to run one of these boards off it as well, and do without the external PS... could be easier than building a separate 3.3V reg.

Admittedly, I'm just thinking out loud here.

I'd trust the FAQ on that one

Now this is something that I haven't read about before - what precisely does that do? Could this be the cause of some of the issues, that the logic board is actually just getting 5v rather than 12v?

I figured that the interference that I'm getting is caused from an exposed wire, as I had cut, soldered, and wrapped the wires with electrical tape rather than crimping that thing - will redo it at some point anyway.

You should have read about it on the takky site--it's a required mod for Takky operation. If you didn't do this mod, then it could be causing a lot of your problems.

This mod doesn't actually supply the precise voltage the x500 boards require here, but it's close enough. The +5v stock is NOT close enough, thus this mod.

Alrighty then. I'm somewhat weary of messing with the analogue board (it took me forever to convince myself to do the VGA mod), therefore I would like to make sure I understand the instructions correctly. I've seen pictures on Stuart's and your site regarding the jumper wire that needs to be soldered on, that won't be a problem. Tak mentions on his website though, that one needs to "cut" J19 - you've said that this is located on the top side of the a/b? I'd like to make sure that I know what I'm doing because frying the CCs a/b is not really a smart thing to do

Update:

I actually went ahead and did the mod. Wasn't that hard after all, heh! While I had the machine open I also went ahead and checked the connections to the A/B and the SCSI cable for insulation that might have gotten lose over the time. Come to find out, some actually did fall off and now that I've redone the connections that weren't properly insulated (and also removing the CD audio connector cable from the harness itself) the interferrence seems to be virtually gone - yay! The mod itself didn't do anything noticable to the machine, therefore I guess I won't be able to use networking and the cache until I install the voltage converter. At least I now know that it's not straining the 5v supply as much. Thanks for all your help!

Ben

P.S.: Found this site with a nice picture of J19, just for future reference http://homepage.mac.com/katsumi_m/colorcla/Takky040.html - only bad part is that it's in Japanese.