LC575 PowerPC motherboard upgrade options?

[OriginalDan]

gday, I've orderd a LC575 system to use the motherboard for the good ol color classic mystic mod as it's ironically cheaper to buy and import an entire system instead of just the motherboard! lol but that had me wondering what can i do with the left over LC575? one of Action Retro videos mentioned @6:40 "several powerpc boards that could slot right in" but hang out the back a bit which i can solve with some 3d printing, but the only info i found was on micromac
are the 5200/6200 motherboards the only upgrades that fit into the 575? or are there others? anyone on this fourm tried these kinds of upgrades?

 

[Phipli]

gday, I've orderd a LC575 system to use the motherboard for the good ol color classic mystic mod as it's ironically cheaper to buy and import an entire system instead of just the motherboard! lol but that had me wondering what can i do with the left over LC575? one of Action Retro videos mentioned @6:40 "several powerpc boards that could slot right in" but hang out the back a bit which i can solve with some 3d printing, but the only info i found was on micromac
are the 5200/6200 motherboards the only upgrades that fit into the 575? or are there others? anyone on this fourm tried these kinds of upgrades?

If the 6200 fits, the 6300 will fit just as well, they're the same form factor and electrically compatible. The 6400 and 6500 will fit, but need a mod because they need 3.3v which wasn't used on the older boards.

AIO equivalents work for all of the above.

But... Given these are 30 year old machines, why not just use the 575 as a 575 and the ColorClassic as a ColourClassic? It feels a shame to be pinching boards from a now fairly rare computer?

 

[pizzigri]

None of these will work unless you build a Takky 575, which, btw, would be supercool due to the larger and much better crt and 640x480 native resolution…. not to mention the CD-rom player etc etc.

 

[Nixontheknight]

None of these will work unless you build a Takky 575, which, btw, would be supercool due to the larger and much better crt and 640x480 native resolution…. not to mention the CD-rom player etc etc.

you can actually mod a color classic analog board to output 640x480 with a VGA mod, which was shown in detail here at one time

 

[pizzigri]

Yep I know, OTOH it’s a mod that burdens the aging and anemic original CC power supply way too much … and it’s stock on the 575, hence my reply.

 

[Nixontheknight]

Yep I know, OTOH it’s a mod that burdens the aging and anemic original CC power supply way too much … and it’s stock on the 575, hence my reply.

I meant there's one that doesn't put as much strain on the power supply

 

[OriginalDan]

If the 6200 fits, the 6300 will fit just as well, they're the same form factor and electrically compatible. The 6400 and 6500 will fit, but need a mod because they need 3.3v which wasn't used on the older boards. AIO equivalents work for all of the above.

awesome is there a guide on what needs to be modded for 3.3v? though id imagine you could use a picopsu instead

But... Given these are 30 year old machines, why not just use the 575 as a 575 and the ColorClassic as a ColourClassic? It feels a shame to be pinching boards from a now fairly rare computer?

well I'm fairly new to vintage macs, mostly recently collected vintage dos/windows over the last few years, so plan was to beef up a color classic for fun but have something that can check out everything from the 040 era and prior in a small all in one system and reuse the empty 575 now if it can fit something as beefy as a 6500 then it could be a gaming rig for myth1&2 and other mac exclusives of the era, i think myth2 recommends a 120/200mhz? and has 3dfx support though i dunno how well cards will fit in there

None of these will work unless you build a Takky 575, which, btw, would be supercool due to the larger and much better crt and 640x480 native resolution…. not to mention the CD-rom player etc etc.

are some of the 6X00s not pin compatible? i was hoping to avoid a takky mod because of that added complexity and I'm still rubbish at custom wiring x)

 

[Phipli]

awesome is there a guide on what needs to be modded for 3.3v? though id imagine you could use a picopsu instead

From what @pizzigri is saying it sounds like you have a load of work to do to get any of those boards into the 575 before you get to the point of considering the 3.3v mod?

 

[Phipli]

myth1&2 and other mac exclusives of the era, i think myth2 recommends a 120/200mhz? and has 3dfx support though i dunno how well cards will fit in there

I forget the processor specs for the Myth games, but if you really want to throw money at it you can put a G3 Upgrade in a 6500 board, but they're not cheap. You might be cutting a lot of plastics to get all this in there. Plus will certainly need to uprate the PSU.

You'll struggle to fit a 3DFX card in there, and again, they aren't cheap. Myth supports software rendering though if I remember. The 6500 has a built in Rage IIc, sadly only with 2MB of VRAM which completely hobbles it for 3D gaming (it technically supports QuickDraw3D / RAVE).

If you want that era of gaming you might be better finding a Beige G3 and an ATi Rage 128 or Radeon 7000. Processor upgrades are much cheaper for those machines and the base computers are too, plus you can use them with any old VGA LCD once you have a PCI graphics card.

 

[Daniël]

awesome is there a guide on what needs to be modded for 3.3v? though id imagine you could use a picopsu instead

You can basically follow the 3.3V part of a Color Classic Takky mod guide, on how to get that to work:

Takky | powercc.org

A Takky Upgrade is to fit a logicboard of a PowerPC into the Apple Color Classic. It gives you much more Power than the original components.

powercc.org

They suggest also adding an additional PSU if you're planning on adding a lot of power hungry components, which I would suppose would still be the case with the 575.
I wouldn't suggest a PicoPSU, as you'd still need 12V, and other than clunking in a 12V brick somewhere, there really isn't a good way of getting that at sufficient amperage (tapping 12V from the 575's PSU would still add that load to the PSU, and to just one of its power rails).

 

[OriginalDan]

From what @pizzigri is saying it sounds like you have a load of work to do to get any of those boards into the 575 before you get to the point of considering the 3.3v mod?

it looks like the 6500 has the same edge connector? but yeah i have no idea if it's fully pin compatible, the assumption was based off the MircoMac site atleast the 5200 75/90mhz versions should be slot in compatible without additional mods? but with how unfamiliar i am with macs is why i asked here before hunting down parts

if you really want to throw money at it you can put a G3 Upgrade in a 6500 board,, Plus will certainly need to uprate the PSU,, You'll struggle to fit a 3DFX card in there,, If you want that era of gaming you might be better finding a Beige G3 and an ATi Rage 128 or Radeon 7000

yea those G3 upgrades are nutty priced, beige G3 would be the sane option but then it wouldn't be a tricked out all in one lol i dunno why i just really like the compact AIO type macs that don't take up much desk space, i love me original crts which is why I've got a monster 21" I'm trying to KVM all my systems to it, but adding macs into a kvm mix would be a bit of a nightmare with anything pre vga/usb
Already have a couple AGP/PCI voodoo banshees & voodoo3s i know my way around blender so i could model something up to make it work like this:


but now it kinda seems like a bit overkill fever dream setup haha so back to reality i don't want to leave the 575s tube unused as i have somewhat limited space so trying to min/max space with working systems is ideal instead of a good 14" tube going to waste

You can basically follow the 3.3V part of a Color Classic Takky mod guide, on how to get that to work: They suggest also adding an additional PSU if you're planning on adding a lot of power hungry components, which I would suppose would still be the case with the 575.
I wouldn't suggest a PicoPSU, as you'd still need 12V, and other than clunking in a 12V brick somewhere, there really isn't a good way of getting that at sufficient amperage (tapping 12V from the 575's PSU would still add that load to the PSU, and to just one of its power rails).

thanks for the link, there's 160w with 200w peak picopsus, quick google seems the 6500/300 peaks at 220watts?
In theory if we went down that route you could mount a Type-C PD Trigger Module that way minimizes the psu internally to run a single USBC cable out to a high wattage GaN charger. but that would be getting a bit complex considering how unfamiliar i am with macs in general lol

i think safe bet would be first trying a 5200 atleast that mods been done before, just wanted to double check there wasn't any missing steps, risks or people who have tried similar mods or what other slot in compatible gear is out there

 

[Phipli]

the assumption was based off the MircoMac site atleast the 5200 75/90mhz versions should be slot in compatible without additional mods?

The 575 and 5200 boards look very different to me?

575 :


5200:


The edge connector is almost twice as wide, and reversed? The 5200 is also a deeper board.

 

[beachycove]

The Micromac product included an adapter board (soldered onto the new logic board), which converted the edge connector. So what you are talking about is not a simple DIY solution.

I happen to have the Micromac upgrade pictured. It is destined for eBay, as my LC575 fell to pieces, I was moving, the COVID lockdown was on, and some things just had to get thrown out (though the logic board got sold, drives saved, etc).

Micromac’s solution used 5200 boards and their derivatives. The bucket at the rear end was metal. Mine had the better 5260 logic board or some such in there — though I strongly suspect that something like a 6400 board could be made to work by someone with the requisite soldering skills. Alas, that’s not me. One of the interesting things about the adapter board is that it includes a jumper allowing for a selection of machines. The Color Classic is listed.

No good to ask for pics just now, as it is in storage and I am not at home for the next couple of weeks in any case.

 

[OriginalDan]

The 575 and 5200 boards look very different to me? The edge connector is almost twice as wide, and reversed? The 5200 is also a deeper board.

The Micromac product included an adapter board (soldered onto the new logic board), which converted the edge connector. So what you are talking about is not a simple DIY solution.

aaah okay that certainly clears things up, didn't realize it needed an adapter, with how it was described it all sounded like a slot in replacement lol makes sense why i couldnt find anyone having done a similar upgrade before

whenever you get around to it please share them outside ebay as ebay will auto delete listing photos awhile later
it might be a straightforward project to reverse engineer the adapter from photos into a pcb then folks can get theirs via pcbway or some such, I'm certain the mystic mod has left a lot of empty 575s out there.
looks like ill need to brush up on my wiring skills lol

 

[pizzigri]

Well, there is a very interesting fact about these machines, the ABS of the color classic is seemingly completely different than the plastic that was used in the 575… matter of fact while most of the 575s have crumbled to pieces just by looking at them, most of the color classic cases that I’ve had the chance to play with, seem to have aged vastly better and are not that brittle. basically that means that there are very few 575 around today making them rarer than the CC. I am not that convinced you will find many 575 cases for sale and even then there’s a 70% chance you’ll receive beige shrapnel in the box…

 

[pizzigri]

Plus, there’s no way you will easily make a 3dfx work in a Takky 575, not only because it is already difficult to make it work in a stock 6500 - trust me, I tried! - but because in a Takky mod you’d have to reroute the vga signals out the logic board to the card and back to the internal crt…. mind boggling.

 

[Phipli]

Plus, there’s no way you will easily make a 3dfx work in a Takky 575, not only because it is already difficult to make it work in a stock 6500 - trust me, I tried! - but because in a Takky mod you’d have to reroute the vga signals out the logic board to the card and back to the internal crt…. mind boggling.

You can use the GIMO port on the board with the dsub connector that goes to one of the blanking plates with a 15 pin dsub. You could even rewire it straight to a VGA port if you felt eager. You'd still need the loopback for the 3dfx early cards.

 

[macuserman]

Personal opinion here but the 575 is a way better machine than the CC, also far more rare. Dunno but I'd probably keep the 575 as a whole unit vs gutting it to upgrade a CC. Not sure why the trend to hack them up started, but has only increased the rarity of good 575 examples. Worth considering anyhow.

 

[pizzigri]

I have the output board that goes to the GIMO slot however the video quality is horrible, all washed out with hard contrast and weak colors….

 

[Byrd]

I have the output board that goes to the GIMO slot however the video quality is horrible, all washed out with hard contrast and weak colors….

I’ve used the Apple output GIMO board on both a 5500 and TAM; seems alright quality maybe try another monitor.

Never seen an input GIMO board but colour me interested. Could be an amazing way to get video input on an AIO early Mac or the delight of seeing it switch over from a 3D PCI card would be fun.

Also agree a good solid LC575 is an amazing machine, you might learn to love. The Trinitron CRT is a gem and I’ve always felt the 575 was Apple’s highest quality AIO Mac released.