Franken Mac 8600 First Look

Sounds 'cool', even if only metaphorically, and makes my one-time 8600/200 now living as a 9600/400 seem bog-standard by comparison.

Enjoy!

de
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(60x) 13DT + 3PB + PTPro; (G3) 7DT/MT; (G4) 3T + PB. System 8.1 to OS 10.5.8

ive seen this before. The heads get magnetized. Try demagnetizing the heads. 

Two ways this happens, well 3. one is poor storage near large magnets. speakers, etc. 

Other ways include the disk flap being magnetically charged, or something going wrong with the head bias circuitry putting a strong DC bias on the head, therefore magnetizing the head. bad capacitors will do this, in the drive. 

How much did the dual G4s set you back? Were there any issues with using them in the DA board? How did you mod the 8x AGP?

Sounds like your Bournes Filter failed, that is, if the heads are OK, the only thing that could do this is the Bournes Filter.

Take out the heads and open it slightly as if you were about to clean it, and look at the spring the top head rests on. If it perfectly flat? If it is, then its the Bournes filter of SWIM Chip and I'm betting on the Bournes Filter. Those things fail if you look at them the wrong way.

Techknight can be right too. Got a head demagetizer? I have not seen one since the 1980s, though it still might be in my bedroom - lol!

Well then! Thanks for the incredibly fast responses. That's very helpful.

Now I will go and figure out how to de-magnetize the heads and investigate the Bournes filter.

The DA G4s cost me about $100. That was a real steal. I bought it with an "as-is" 2002 Quicksilver that had undiagnosed problems. I needed a power supply and motherboard, and I figured at least one of the three components would be good. And even at $100, that was a deal. PSU goes for about $75 - $100 on eBay, mobos are $50 - $75, and dual G4s cost upwards of $150.

I came out on the positive side with a power supply and dual G4 CPU module.

There are no issues using the dual CPUs on the DA board except the requirement for the extra 12 V (which I stole from a hard drive power connector).

Peace,
Drew
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Power to the PowerPC!

the bourns filter wont kill the data on the floppy disk unless you are telling it to write/format. 

Try flipping the lock lever on the disk, if it still corrupts it, its magnetized heads, or the bias supply is running when the disk isnt being called to write. 

i am trying the same thing in a B&W case how did you add the extra 12 v wire.

i asked several related question on 68kmla for my project

which mobo can i use with my existing B&W psu

well you could connect the floppy drive from your 7600 to the se/30 and see if it still does it.

otherwise it does kinda sound like a magnetized floppy head.

Sorry I didn't see this earlier. The 12V connects to the fourth "leg" on the QuickSilver CPU module. Basically, once you screw down the QuickSilver CPU module on a Digital Audio, you'll notice that only three of the posts will make contact with the daughtercard. Where the 4th post is on the QuickSilver, there is no post on the DA. This 4th post carries 12V from the motherboard to the daughtercard.

So to add the extra 12V, you must tap a 12V line from the PSU such as one of the yellow hard drive power cables. I use a short bolt and nut through the fourth hole on the CPU module and either fasten the bare wire directly to this or use one of those fancy electical connection pieces that crimp onto the end of the wire and add a little washer that you can place under the bolt.

I hope that's the information you need. If not, I'll see about taking some pictures of it.

Peace,
Drew
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Power to the PowerPC!

Yeah, I don't even get to the point of being able to write to the disk.  As soon as I put a disk in, I am told it's unreadable. If I try to format in the SE/30, it farts out a borked disk.

Will any tape head demagnetizer work? Or are they not all equal? Thanks again!

uniserver said:

well you could connect the floppy drive from your 7600 to the se/30 and see if it still does it.

otherwise it does kinda sound like a magnetized floppy head.

Click to expand...

That, sir, is an excellent idea. When I crack the SE/30 open I will give it a shot. my back room currently looks like a tech bomb went off, so best to add to the mess. Oh yeah, and parts of the Plus are around too... yeah you'll be seeing that in your future.

I think deer steak is trying to do a case conversion. He wants to put a DA board into a B&W case which is significantly more possible for the hobbyist than putting a DA or QS CPU on a B&W motherboard.

On the other hand, the DA G4 and up had four PCI slots and an AGP slot for a grand total of five expansion slots. The B&W only has room for four (4) expansion slots without significant case modifications worse than what is required by an 8600 (which has room for six! slots).

What are your plans, deer steak?

Peace,
Drew
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Power to the PowerPC!

thought id throw in my 'thumpense' worth here.

bening a musician , I had to de-magnetize recording heads a good few years ago. The gadget was called a degausser if memory serves

I don't know if the next part was necessary but the procedure was to never switch the degausser on next to anything magnetic (disc drives, heads etc etc). The instructions said

to leave the room, go outside, switch it on, then goto the heads in question and just hold the degauser next to the head.

The degausser emits random magnetic fields, so being close to a harddrive would not be a good idea.

But as I said, it was 20 years ago, and I could be wrong. But worth checking out , just to be sure.

Sorry for the confusion.

i have a B&W with a 700 mhz sonnet upgrade 1 gig of ram with 10.4.x. the machine feels slow. the sonnet upgrade reduced the bus speed to 66 mhz. So i am looking for a cool upgrade path. I love the B&W case and I am not willing to give up on it yet. I have realized that the zif processor mobos will not get me where i want to go. this means i need a sawtooth through quicksilver mobo but which one? i would like to keep as much of the B&W as possible hard drives, memory, PSU, graphics card. I know that I could use any of the motherboards for the g4 "except yikes" with a 3rd party processor and make it fast. I would like something >700 mhz and you can get quicksilver processor at a good deal on e-bay sometimes. if possible I would like to use a stock apple processor like alk did.

My goal is to use the new stlye (sawtooth) processor card in my B&W

I am willing change out the psu if it makes a better machine in the end.
michael

Ah hah! That clears it up.

I would drop in a 2x AGP G4 motherboard such as a Sawtooth or GigE board. The CPU modules used on G4s (except the Yikes!) will not work with a B&W motherboard. The 2x AGP boards have three PCI slots and 1 2x AGP slot for a grand total of 4 slots. Which is also conveniently the same number of slots on the case for your B&W.

You might still need the back panel plastics and metal from a G4 to make a seamless fit, though.

Other than that, you should be able to use everything else that was stock on your B&W (even the graphics card). Of course, a 2x AGP card provides a huge improvement over PCI graphics...

I'm also not certain of the power requirements. You may need to do some hacking on the B&W PSU to mate it up to your G4 motherboard, and all G4 motherboards need between 24v and 28v (as alluded to by bunsen) on one pin. You could just drop in a Sawtooth PSU while you're at it, too.

By the time you're done with all this, you'll probably have paid as much as it would have cost to just buy a Sawtooth G4. So I'd actually recommend you do that and just swap the B&W plastics for the grey plastics of the G4.

Peace,
Drew
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Power to the PowerPC!

You can search ebay or Amazon, but you are looking for something like this (one of many from Amazon):

http://www.amazon.com/Universal-DEMAGNETIZER-Cassette-Recorder-Track/dp/B003ZKLP4W

Put it on the top of the heads without pressing down, turn it on and pull up and in a away slowly in a increasing spiral motion. Should take 30 seconds to do.

They come in many shapes and sizes.

If you decide you want to part with the 700MHz ZIF, think of me

You can use a big 230watt soldering gun as its transformer based. In close proximity. Itll demagnetize the heads and everything around it.

Same process. Swirl and back away

I have been studying the psu differences between the g4 models.

and found this page

www.outofspec.com/frankenmac/wire.shtml

the mobo after sawtooth require a 28v.

in addition
the cpu module requires the added 12v to the 4th leg to quicksilvers

so Alk It appears that i could put a sawtooth mobo into my b&w add the 12 v to the 4th leg to cpu module from quicksilver and it should work.

i agree on the money could be spent as cheap on a complete sawtooth. But whats the fun in that.

Elfen said:

You can search ebay or Amazon, but you are looking for something like this (one of many from Amazon):

http://www.amazon.com/Universal-DEMAGNETIZER-Cassette-Recorder-Track/dp/B003ZKLP4W

Click to expand...

Ah! Excellent. Thanks!

Now I am kind of at a loss. The good news is the other floppy drive from the 7600 works fine when attached to the SE/30, so I guess that rules out the Bourns filter being bad. I tried the degmagnetizer and while it was truly a very exciting moment in my life, the result was no change. I cleaned the heads again just to make sure. If anyone has any other ideas, I would appreciate it!

Thanks

you could try adjusting the heads clamping pressure spring.  for me that is usually  the only issue i have with those drives. other then basic clean and lube

I've also heard there are problems with the QS modules' L3 cache not working on older motherboards, even with a 133MHz bus.

/EDIT/ but there's also a mention on Applefritter from someone who says his works fine in a DA.

I found a detailed set of directions for converting an ATX supply for a DA motherboard.

He suggests using the front panel power board from a B&W G3 for the 28V supply. I have one, but I'm probably going to save it for my B&W motherboard. I'm planning to use a Powerbook PS (24V). The frankenmac site you linked suggests 24V will be OK. I may be able to tweak the PB PS to give a couple more volts.

I would like to use a DC-DC step-up converter off a 12V line, but I can't find one cheap and powerful enough.

I would also recommend using an ATX cable extender, so you can swap out your ATX supply simply should it ever die.

you could try adjusting the heads clamping pressure spring.  for me that is usually  the only issue i have with those drives. other then basic clean and lube

Click to expand...

can you give more explanations, as i have also a floppy which didn't worked after a good clean up.

Apparently you can get away with just connecting the ATX +5V standby lead to that input. Details from Applefritter.

you remove the heads,

To do this you take out 2 screws, the ones holding the round bar in place and it pulls right out.

carefully pulling out the top and bottom head flexible cables, with some tiny electronics needle nose pliers.

There is the spring (top and bottom) head clamping adjustment adjustment perch (3 positions), i usually adjust the spring to the next highest perch. increasing tension.

and usually it works fine.

Working with dad long ago fixing Macs and learning a lot from him, I have to ask, where are these "tension screws?" I have never seen screws on the head of the floppy drive to do adjustments with. Mind if possible to post up a pic of it? Are they part of the newer drives found in PowerPCs with the black doorways?

I'll try and make sense of all of that later tonight when I have it in front of me... right now I can't visualize "head clamping adjustment adjustment perch"

Thanks for pointing me in some direction that may work!

uniserver said:

IMG_1648_thumb.jpg

IMG_1649_thumb.jpg

IMG_1650_thumb.jpg

Click to expand...

So that is the back close to the bottom of the heads with the head flipped over up-side-down. I remember being told not to ever touch that area and two screws that hold down the top head to the assembly (can be seen in third picture in your post) or I would throw off the alignment permanently.

Gotcha well all i am showing here is, increasing the head clamping spring pressure, witch i am sure over the years has been reduced.

Learn something new everyday.

uniserver said:

Screen Shot 2014-09-19 at 12.53.27 PM.png

Click to expand...

Hey Uni,

Thanks for taking the time to take all of those pictures and putting them up here. I went through the entire exercise and was able to do exactly what you said. Unfortunately, it didn't change the outcome.

I don't think she's comin back, boys.

you probably have a DC bias stuck on the heads from either a bad capacitor, or a bad IC in the drive electronics. 

Hey techknight, so it was probably a ticking time-bomb all along? Would a bad floppy have been the nail in the coffin? A less then ideal environment of stuttering or vibrations pushed it over the edge? Or just a coincidence?