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LC 580 CRT swap
Posted by: rsolberg on 2015-09-16 09:52:25
The recent thread about LC 5xx front bezels got me thinking about the LC/Performa 580. Historically, I generally preferred the 575, due mainly to its Trinitron display with much finer dot pitch. I find the 580 has significant appeal to me now as hard drive replacements or conversion to CF storage are trivial compared to earlier machines due to its IDE bus. It seems to me the logic board also has a slot that accepts the Apple Video System or a tuner.

Has anyone tried swapping a Trinitron tube from a donor 5xx into a 580?
Posted by: uniserver on 2015-09-16 10:11:25
one might be able to swap the tube with the Analog board,  ( maybe )  i would need to see pictures of the 580 AB.
Posted by: Trash80toHP_Mini on 2015-09-16 10:55:51
Hrmmm? Sounds like a project I abandoned when I moved six years ago. I was in the middle of doing a dumbo eared TAKKY with a 575 and it seems to me that the same sorts of things might be required going at it from your direction as well. Dunno, no expert here, but there used to be a lot of info available online for the CC TAKKY conversion which appears to have gone missing. Such made it possible to muddle through my twisted  approach the procedures. You've already got the plastics part of the hack done, so it might be easier! [🙂] ]'>
Posted by: uniserver on 2015-09-16 11:12:37
yeah the 575 Tube+AB put into the LC580, sounds much easier then PPC TAKKY stuff even.

the AB might just slide right into the EDGE connector?
Posted by: Trash80toHP_Mini on 2015-09-16 11:55:34
Nope, as I understand it, you'd probably need to reverse the wiring harness tweaks documented in the Frogeye diagram:



http://homepage2.nifty.com/frogeye/connector.html

http://homepage2.nifty.com/frogeye/takky.html

YMMV, like I said, no expert here. :🙂

Posted by: uniserver on 2015-09-16 12:21:16
do you have this image for the CC / 575 and 580 for comparasons?
Posted by: uniserver on 2015-09-16 12:26:20
ahh i kinda see what you are saying... its like the 580 might even be more comparable for the PPC stuff 🙂

Screen Shot 2015-09-16 at 3.24.51 PM.png
Posted by: Trash80toHP_Mini on 2015-09-16 14:07:42
Looks like a PC compatible (check the short edge card connector next to the PRAM battery) LC/Performa bastardization of the Quarda 630 (in)complete with numerically challenged 68LC040. Is that a ROM SIMM in your pic?
Posted by: rsolberg on 2015-09-16 14:38:19
Is that what that short slot is for? I've long wondered. The two SIMMs are both RAM. I'd forgotten that one slot is offset like that. Max ram is 52MB with 4MB soldered, one 16MB single sided, and one 32MB double sided module. The slot at the bottom of the image is the video connector.

Thanks for the info. Some of my memories of these things are returning.

Here's a fun project page: http://www.mactech.com/2004/06/03/project-black-mac-lc5500225
Posted by: Trash80toHP_Mini on 2015-09-16 15:34:32
If it has two DRAM slots, it's the best 630 based board you can get and it's definitely PC Compatibility Card ready!
Posted by: techknight on 2015-09-16 20:20:47
That short edge is for a secondary monitor. I have the cable for it.
Posted by: Trash80toHP_Mini on 2015-09-17 06:12:48
I've got the cable you're talking about, was that intended for mirroring to a projector in schools? That was my understanding. In auctions, I've only seen them installed in 5XXX AIOs. Interesting, the little LC Slot portion of the Apple PC Compatibility Cards cable to that MoBo connector and to the Processor portion of the card, which funnels PC video(?) to it. The Reply double-decker setup uses an edge to edge PCB to bridge the connection to the top board while the bottom board plugs into the LC Slot instead of the processor socket where the Apple card is wedged into the system.

The I/O setup is very strange in both cases. I wonder if my Quadra 630 would work with Apple's PC Compatibility Card so long as it had two dedicated monitors even though no edge card connection is provided? Time for a new peripherals thread methinks.
Posted by: Apache Thunder on 2015-09-27 20:41:35
I recently read about the 580 on wikipedia:

"Lastly, the Trinitron display of the 575 was replaced with a cheaper shadow mask screen, causing a slight change in the plastic case surrounding the CRT"

From that quote I'm led to believe you might have problems getting a Trinitron CRT to mount correctly in a 575 case. It might not be appearent on the outside. It could be a change in the interior with how it mounts to the plastic. I've personally never own either machine though. I suppose you already decided it's worth the risk. 😛

Posted by: uniserver on 2015-09-28 12:25:09
it was a good thought.
Posted by: rsolberg on 2015-09-28 12:50:21
That makes good sense- the LC 580's screen is more curved IIRC. The external case dimensions are the same, but the bezel is probably shaped incorrectly for the Trinitron tube. It might require filing or filling, or perhaps hacking the 575 case front into the 580 chassis.
Posted by: techknight on 2015-09-28 14:09:36
The 580 has the Goldstar display, with the bubble tube. 
Posted by: TheWhiteFalcon on 2015-09-29 05:53:25
Put a 580 board in a MacTV? Or, just use a MacTV?
Posted by: Apache Thunder on 2015-10-04 20:57:03
Unless you happen to come across one for cheap, I would think using a MacTV would be a rather expensive solution to this problem. 😛

However while the CRT won't mount directly into the front case of a 575, perhaps you can use the front casing of a 575 on a 580 rear case? Unlike the compacts it looks like a majority (if not all of it) of the motherboard is held in place by the rear casing instead. It's just a matter of if the front case will line up correctly to the rear case.
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