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blusnowkitty

ATX to Mac IIcx/IIci/IIsi/IIvx/IIvi, Quadra 650/700/800, Performa 600, PM 7100 Adapter

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God I'm so awed by your project and love it so much guys! But where's the beef? What kind of can are you going to pack it in?

 

F6U5yKM.jpg

 

I don't do electronics or PCBs (at least not in the past 25 years, but what I do do is look a form factors, available cubic and stuff things in where you'd least expect. I've been looking at the Q700 PSU for a very long time, mostly to adapt the stock can to power my Quadra 700/8600/G4 project that uses entirely different connectors. I tore up one Q700 PSU for nefarious purposes, so I'm passing familiar with the hardware.

 

Please don't take this as criticism, none is intended, just "inside the box" suggestions so to speak. I have trouble visualizing how you'll be using your PCB in the configuration above? How's it gonna work, at least with the stock Apple can? Are you modifying it heavily or not using it at all? The only thing that makes sense to me would be mounting the FlexATX PCB to the lid so it hangs upside down next to the stock IIcx form factor cooling fan with its funky black top/housing. You can mount your board to the floor and leave all the extra wire between PCB and the ATX connector on your board. The wires are overly long, but at least they'll be hanging down in a coil to plug into your card.

 

However the 10-Pin connector on your PCB  .  .  .  I can't see that working at all. Harvest the original 10-Pin plug  and wires from the stock supply and hardwire it to your board. Apple's funky connector is engineered to do a lot of things that would stress the connector on your board well past the breaking point.

 

Besides the thicker traces, PLEASE provide mounting holes on the board to bolt it down to the floor, lid, side or wherever is most convenient on the inner surfaces of the stock cans? Think about my suggestions, set up that way  in the original can with the original 10-Pin harness and it should be ready for plug and play  .  .  .   ruggedized per Apple spec.

 

There's a LOT of mechanical forces going on every which way between the Apple's custom connector(?) hanging from those two metal flanges and the square cone shaped entry of the board socket during installation and removal. :approve:

 

p.s. bonus points for conserving the A/C input and monitor passthru hardware to perfectly match the openings in the back of the case.

 

 

 

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10 hours ago, Trash80toHP_Mini said:

I have trouble visualizing how you'll be using your PCB in the configuration above?

We're just using what we have laying around to test, hence the full-size ATX PSUs. Eventually I'm going to switch over to a picoPSU once we get the final design nailed down.

 

10 hours ago, Trash80toHP_Mini said:

Are you modifying it heavily or not using it at all? However the 10-Pin connector on your PCB  .  .  .  I can't see that working at all. Harvest the original 10-Pin plug  and wires from the stock supply and hardwire it to your board. 

Using the original case and harness is up to you - want a tiny board with the 10-pin mounted straight to the PCB? Great! Want to reuse the original 10-pin harness and mount it inside the case? Also doable. That said, in my Rev1 test board I used the original harness from my IIsi's PSU and I'm not sure if it's because the wire is aluminum or the wire had absorbed a lot of capacitor electrolyte, but it was very, very difficult to solder the wires to the board. In the PCB-mount 10-pin idea I don't really see it being that big of an issue not having standoffs; a picoPSU weighs practically nothing and doesn't have any heavy wire harnesses pulling on the board in a weird way.

 

10 hours ago, Trash80toHP_Mini said:

p.s. bonus points for conserving the A/C input and monitor passthru hardware to perfectly match the openings in the back of the case.

I did to an NCR 386 desktop a while back and it's not hard to do. However we're not planning at this time to offer this as part of the kit as we don't want any liability if someone ends up wiring the AC side wrong and kills themselves.

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I thought it best show what I'm failing badly at putting into words with some pictures. If you have a specific plan in mind for using the PCB as shown above, please correct me. Again these are but suggestions.

 

Q700-PSU-ITX-FlexATX-001.JPG.thumb.JPG.1554716ef7ab0682a72af4ee1c6b3d60.JPG

 

Overview: ITX-FlexATX PCB is on left, where it would be mounted to the lid of the Q700 PSU can in place of the PCB mounted there in the PSU's stock configuration.. Apple's PCB remains on the bottom of the PSU box in the pics because it's too complicated to remove except in the case of hacking the case, it's hardwired to the power connector assembly. When it's removed the top of the components of the FlexATX PCB are considerably closer to the top of the OEM lid than they are from the bottom of the can.

 

Details:

 

Q700-PSU-ITX-FlexATX-000.JPG.thumb.JPG.a94d2f74613d3e76bd87cb3705277410.JPG

 

It'd probably be a good idea to tape over the the bottom half or the air intake holes to ensure that the fan sucks all the air across the FlexATSX' business parts.

 

Q700-PSU-ITX-FlexATX-002.thumb.JPG.c163d967251af4f061528d149ff5b0cf.JPG

 

The Apple connector allows movement around the clock for lining up with the board's socket during installation, that's really important.

 

edit: I see you've replied while I was proofreading! Selling completed boards is a great and I fully understand the liability thing. Selling the kits with everything but the molex connectors oh board with a strong "USE AT YOU OWN RISK" warning would be the way to go. I'd add that warning and the "manufacturer assumes no liability" verbiage I've seen on everything as well. But please, please, please add the mounting holes I suggested. Your board would be mounted with standoff to the IIcx and IIsi PSU can installations as I've described. They'd make it easier for me, especially if you provide grounding plane connected pads to both sides of the PCB for those holes!

 

Edited by Trash80toHP_Mini

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Forgot to mention the Molex peripheral power connectors snaked out through the "low rider" 10-Pin connector setup. You can just make them out in the center pic.

 

Suggestion: mostly assembled kits could come in three flavors, with one Molex connector or the other installed or no connectors installed. None for IIsi can installation and only the ATX connector installed for the suggested IIcx form factor mod pictured above.

 

One last thing before turkey time: with your ATX, Molex only option DIY board bolted down to the floor of the can, there's plenty of room left over for the 12V to 5V Buck Converter @trag suggested for bringing 5V output up to snuff.

 

Happy Thanksgiving! [:D]

Edited by Trash80toHP_Mini

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So here's the thing: Fitting something with higher power is complicated(tm) due to space constraints. Apple didn't leave a lot of room for a power supply and your standard PC size form factors aren't the smallest things.

 

Overall to fit (and be able to plug a mains cord in) you'd need to be shorter than ~5.25 inches. Max height to allow for adapter board is about 3 inches. Being as this isn't really intended as an advanced gut a PSU DIY kit, that severely limits the options. I'd rather not suggest people open PSUs up and hack off wiring and such.

 

One option would be https://www.fsp-group.com/en/product/pcpsu/1503479602-610.html . It'd fit entirely within the factory frame without needing gutted. It'd probably even allow you to plug a mains cord in and have room for cable slack inside. The catch is you'd need to have a mains lead running out the back attached forever. The connector doesn't line up anywhere near the factory holes. 

 

There're a plethora of other PSUs made by FSP, Enhance, CWT, etc that'd work but they aren't normally retail PSUs and as such availability is spotty without ordering in bulk from them. There's also some medical PSUs that'd work but at $200-$300/ea they aren't feasible.

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Okay another update: I managed to find another bug and fixed that. It wasn't a critical issue - it'd just limit you to 74HCT04s instead of being able to use a 74(L)S04. Being as the HCTs are the easiest to get working, I'd prefer 'em anyway but someone might have some LSs kicking around.

 

I've also significantly reworked the board once again. The biggest change now is +5V and ground are now planes, rather than traces. The main advantage to this is significantly higher current handling, meaning burning a trace isn't as big of a worry. This also allows for less traces making for a smaller board. There was also some basic rerouting of some stuff, allowing me to group the resistors together and make for an overall cleaner board. New additions to the board are a soft power bypass switch to force the power on and two holes for standoffs. I'm unsure as to what'll be used for standoffs at the moment - I need to start doing measurements on the various systems I have and talk others into measurements. All the computers have different components around the power connector, making it not a good one-size-fits-all problem. Now I mainly need to work on the silkscreen - there's some mess going on. 

 

image.thumb.png.7614065eafb9930cbc330c72e5befb8a.png

 

V2R4_Top.thumb.png.601bfe910f1b44cc621dd68d5e312d1b.png

  

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That's looking seriously good!

 

I will buy atleast one (for my IIsi), if not 3 or 4 depending on price. However I think I will wait until there's some kind of 'list' of PSU's that would make good replacements for each model it's compatible with.

Hopefully someone here can create some kind of chart or small database.

 

Of course I suppose the ways you can implement a PSU to fit is only limited to the area the old one occupies.

 

What would be cool is if there was an easy and cheap source of PSU that can not only be wired up easily, but also fit into the original housing of the old supply with a minimal effort as possible for ultimate stealth look.

 

That said, even if you have to mount it somewhere on the internal chassis and dangle a power cord out. It is certainly better than a dead machine!

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1 hour ago, tokyoracer said:

What would be cool is if there was an easy and cheap source of PSU that can not only be wired up easily, but also fit into the original housing of the old supply with a minimal effort as possible for ultimate stealth look.

 

That said, even if you have to mount it somewhere on the internal chassis and dangle a power cord out. It is certainly better than a dead machine!

80 watt picoPSU - $30 on Amazon. Grab yourself a small 12v power brick from your favorite charity shop and wire it up to the original power socket, and you have a complete stealth PSU replacement. I tested the fit out with one of the early Rev1 boards in a IIsi case and when reusing the original PSU harness there is plenty of space to spare to fit a bare 12vdc power supply inside.

IMG_4004.JPG

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Very nice! Since you've said that fitting everything into and rewiring the original can's bits isn't a concern/something you'd wish to encourage, I've re-thought the IIcx installation. Designing a new can to the mounting spec of the old wouldn't be a big deal. Galvanized steel, laser cut with perforations along the bend lines would make it a simple fab using a Big Box available seaming tool. Install own topped box with a large opening for plugging in your board as intended in the bottom could work out nicely. Are strain relief blocks for AC wires readily available?

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14 hours ago, blusnowkitty said:

80 watt picoPSU - $30 on Amazon. Grab yourself a small 12v power brick from your favorite charity shop and wire it up to the original power socket, and you have a complete stealth PSU replacement. I tested the fit out with one of the early Rev1 boards in a IIsi case and when reusing the original PSU harness there is plenty of space to spare to fit a bare 12vdc power supply inside.

IMG_4004.JPG

Neat, I totally forgot about the Pico solution! Wouldn't be too difficult to hook it up to the standard 3-pin 'kettle' socket either if short enough. 

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Good news - rev2 boards are in today! I've built a couple of them up for testing and here's what we've found:

 

  1. 74LS04 inverters don't work - they'll immediately cause the power supply to turn on as soon as they get 5VSB. 74HCT04s work as expected.
  2. The support holes for the Mac 10-pin plug aren't aligned properly and cause an extremely tight fit in the PCB
  3. The resistors for the Power and Standby LEDs are too low causing near blindness when looking at.

I'll be sending off some kits to @Compgeke to see if we can get the 74LS04 issue worked out, and  then it's onto Revision 3! As far as layout goes this is more or less what the final board will look like. Last two pictures are of the board itself plugged directly into a IIsi and the board sitting in the empty IIsi PSU shell. Plenty of space!

 

 

IMG_4056.JPG

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The good news is I think I've got the 74LS04 issue sorted out ahead of time. Using the earlier test board I hacked up a super professional test jig and managed to get the 7404 and 74F04 working. I'd imagine the 74LS04 should also work now. 

 

Something I might also play with is using an NPN transistor. I should be able to more or less "switch ground" so to say by powering the transistor the /PFW rail.  That's not something that'll be showing up on the final design though, more of a curiosity test. 
 

 

yPxQfu9.jpg

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The transistor approach is what I did  when adding soft power to my IIci and IIsi using ATX PSUs. Two resistors and a transistor on a really small board and presto - soft power. The details are in a thread I linked to earlier on. 

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Looking back at that thread I think I had indicated I used a PNP transistor but I think it was an NPN transistor as I think the power on signal from the Mac logic board goes high when the unit is turned on. The transistor then inverts that to a low signal to turn in the ATX PSU. 

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On 12/5/2019 at 1:18 PM, superjer2000 said:

Looking back at that thread I think I had indicated I used a PNP transistor but I think it was an NPN transistor as I think the power on signal from the Mac logic board goes high when the unit is turned on. The transistor then inverts that to a low signal to turn in the ATX PSU. 

This design is pretty much final; I don't think we're going to move to a transistor unless something drastic happens with the 7404. That said, there is a "just for fun" Micro edition of the adapter board, made almost entirely with SMT parts that does use a transistor. We'll see if that turns into a shipping product when I get my hot air gun. https://twitter.com/compgeke/status/1201714914584231937

 

 

 

Tonight it's time for a little bit of fun! We're almost to the final revision so it's time to start writing up the paperwork. I felt it would be particularly appropriate to do it on classic Macs, so here you go. Initial vector work is done on my Mac II with dual displays (LC II is just a monitor stand right now) in Illustrator 5.5, linked to my green SE via serial because the Mac II doesn't support 1.44MB floppies, then copied over to an iMac G5 with Illustrator CS3 to print. I bet you this entire table uses at least 500 watts combined.

 

IMG_4088.JPG

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I managed to get V2 boards a day early and really early. Like check tracking when I got up and "Delivered: 6:54 AM".

 

Electrically they work 100% fine. No need for bodge wires to make them work! 680 ohm resistors have gotten the 7404 to work properly, no matter which variant you install.  You'll notice some bodge wires here - that's playing with current handling. Using just the fairly small PCB traces, I can power a Mac IIci, Supermac Spectrum/24 PDQ, RasterOps PaintBoard Li, Toby video and a single 3.5" Quantum hard drive. The voltage starts to sag quite a bit though - getting me barely ~4.7V. That's not good enough. Add a 2nd hard drive and it'd drop below 4.6V and the system won't start.

 

The patch wires there are just for extra current handling. They're 20 gauge copper so not terribly big. With these I can run all the above plus a 2nd hard drive and still get 4.8V. The next board revision will have planes rather than small traces and should help significantly.

 

5CaOOIz.jpg

 

 

As for the placement, the board now has the 10 pin on the opposite end of where it was before. This allows it to plug into a IIsi motherboard directly. There's plenty of clearance between it and the SCSI connector so that won't be an issue. 

xv0x81H.jpg

 

The next thing are the LEDs. Doing some testing I had with random chinese $0.01/ea LEDs, 4.7K worked great. Of course, we have higher standards for actual stuff and called for Cree LEDs (~$0.10/ea as singles, not a huge difference). I've got some of the red Crees but they're way too bright on the 4.7K resistor off the 5VSB rail. Upping it to a 10K helps, but the LED is still retina searing bright straight on. They really don't need much current. We're going to grab some Lite-On LEDs and hopefully they'll be somewhat worse LEDs. I mean that in a good way. Picture below has Chinese Green old school tech in front, Cree in back, both on 4.7K resistors on a 5V rail.

PqZyEXv.jpg

 

 

Next board will be ordered Soon(tm). It's going to move +5V and Ground to planes, clean up the resistor placement and include standoff holes. If it works fine and can handle heavy loads, it'll become the final revision. 

vKgXBWL.png

 

 

 

 

Overall, project's going good. Here's a pile of test boards I've built :) 

UERTgEP.jpg

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Good news and bad news. Good news is that I got Rev 3 boards in today and they're looking great! Switching to Lite-On LEDs has also solved the problem of status lights being way too bright - I'm pretty sure those CREEs we bought last time were for things like emergency exit signs and not general purpose indicators like what we need. The bad news is that at least for me, 680 ohm resistors aren't working as they only cause my IIsi to power on for a second and then shut off. This happens on both HCT04s and LS04s. If I go back to our old Rev 1 resistor configuration (10k and 47k) I can get an HCT04 to come up but an LS04 will not come up. I'll be sending some boards to @Compgeke to test to see if he can replicate the issue. In the meantime, pictures!

IMG_4147.JPG

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74LS and 74HCT family logic probably shouldn't be expected to behave in exactly the same way on identical PCBs from what I recall of Don Lancaster's Cookbooks.

 

https://electronics.stackexchange.com/questions/358620/74ls-vs-74hc-series-ics-for-ben-eaters-8-bit-computer

http://www.elecdude.com/2014/07/differences-in-cmos-4000-series-74ls-74hc-74hct.html

 

Apologies if you've already covered this in your research, just figured familial characteristics might be giving you wonky results and so should mention it.

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On second thought, I'm wondering if the IIsi's soft power circuit does something a little bit weird and needs an HCT04 and different resistors. What I wouldn't give for a  scope right about now.

 

I'll get some prototypes sent over to @Compgeke for evaluation and after that... Does anyone else have a IIsi and would like to try a couple boards out early?

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And as an alternative to that, anyone in the Bay Area or Sacramento Area have a IIsi I can borrow for testing? I'll even recap it for ya if it's not yet recapped as long as I can get something to test with :) .

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20 hours ago, blusnowkitty said:

The bad news is that at least for me, 680 ohm resistors aren't working as they only cause my IIsi to power on for a second and then shut off. This happens on both HCT04s and LS04s. If I go back to our old Rev 1 resistor configuration (10k and 47k) I can get an HCT04 to come up but an LS04 will not come up.

If the soft power signal is one way, adding zener diode to make sure you're not getting any bounce back from the circuit couldn't might help. I see "soft power bypass" on the silk screen layer of your board, but not a dedicated bypass cap across the legs of your IC?

Edited by Trash80toHP_Mini

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20 minutes ago, Trash80toHP_Mini said:

If the soft power signal is one way, adding zener diode to make sure you're not getting any bounce back from the circuit couldn't might help. I see "soft power bypass" on the silk screen layer of your board, but not a dedicated bypass cap across the legs of your IC?

I've tried adding a cap and a diode across PWR_ON and /PFW on the inverter, no luck there. The soft power bypass just shorts PWR_ON to GND on the ATX supply and it's only there for Macs whose soft power has failed.

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2 hours ago, Trash80toHP_Mini said:

You should have a bypass cap between +5V and GND on your IC to do it by the book.

No luck there either. I'll be getting some boards over to Compgeke on Monday; he's got a lot more test equipment than I've got.

 

In somewhat related news, I've noticed a layout issue where 5VSB to the Mac goes through one of the 680 ohm resistors for the inverter. That drops the voltage just enough where a IIsi can't boot properly.

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