Amiga 500 in ATX Tower case.

[idrougge]

I don't think so – it will work when the machine is powered off, but when you turn it on, the Amiga will try to "charge" your 3V standby power line with 5 V. This, you could solve with a diode, as is usually done when mounting coin cells as replacement for the old NiCd batteries.

[Sinphaltimus]

AFAIK it doesn't recharge. CR2032 was the original Barry soldered in place so I replaced that with a button holder. I never put any diode in and it's not having any negative effects on the battery. So recharging is not an issue.

[Daedalus]

In theory it would work fine, but do you really need to do that? Standby power is usually 5V, which gives you enough headroom to fit it with a diode so you can power the clock circuit. You won't be charging it, but you still need to keep standby power isolated from the main power, so either use a diode or mod your mainboard so no power is supplied to the clock from the standard 5V rail. The first option is obviously preferred, but modern machines power the clock circuits from standby because there are typically more circuits involved, such as wake-on-LAN, remote control switch on etc. But the clock by itself should run for years on a battery, so I'm not sure it's worth the effort.

[Sinphaltimus]

Originally Posted by Daedalus

In theory it would work fine, but do you really need to do that? Standby power is usually 5V, which gives you enough headroom to fit it with a diode so you can power the clock circuit. You won't be charging it, but you still need to keep standby power isolated from the main power, so either use a diode or mod your mainboard so no power is supplied to the clock from the standard 5V rail. The first option is obviously preferred, but modern machines power the clock circuits from standby because there are typically more circuits involved, such as wake-on-LAN, remote control switch on etc. But the clock by itself should run for years on a battery, so I'm not sure it's worth the effort.

This PSU it's 3v always on, seperate from all other rails. I guess I'll label and wrap up the line for now. I'll revisit this when I run out of batteries. Thanks.

[Sinphaltimus]

Some more updates...

Found that I needed to cut a notch for the ram expansion after all. Was off by a few pins..



Fixed the last standoff so I can use all4 now.



Took me a bot to figure out how to get the L:ED to work. All good now, first time using one of these switches for an ATX PSU.



Got all the ATX power connections sorted out.



Using this PSU - I know Passive vs. Active. I'm going to keep this connected to a decent UPS so I'm not worried.




New Switch, sizing it up.



New button in, old button out.




Me likey, I just have to seal up the rear to clean it up.



Fits like a glove, no other alterations needed.



I still have to install a real Amiga floppy (top) and a GoTek, (Will be in the bottom tray), I just wanted to see it like this.





Now to adjust my GoTek case for the new OLED display.



Works for me.




OK, let's get some pins installed shall we?



Easey Peasey -



All ready to program, I'll get to that later today - Going to check out FlashFloppy.



Next, I do not want to butcher my working A500 PSU. so instead, I'm going to make my own plugin adaptor for the rear of the Amiga. I ran out of brain power so I stopped this short. I'll continue later today.

first thing you'll notice, the pins on my custom adaptor will never fit in to the Amiga, they are too fat. And you're correct, that's not the intent here. I'm using these puns to create the adaptor which I'm going to fill with hot glue. Once the base of the adaptor is done, I'm going to dremel grond down the tips of the pins until a hole is created. I plan to solder thin solid pins to the ends of each of these then top off with a little more hot glue.

Before I can get to that, I needed to construct a good foundation, I feel I've accomplished that here using old ATX power connections and a dremel.














And there it is. The base foundation of my power adaptor. Not yet glued of course.

[Daedalus]

Originally Posted by Sinphaltimus

This PSU it's 3v always on, seperate from all other rails. I guess I'll label and wrap up the line for now. I'll revisit this when I run out of batteries. Thanks.

Hmmm... That's strange, since the ATX specification still requires 5V for standby power AFAIK. But even 3V should be doable with a diode, after all, 3V lithium cells through a diode work fine, just organise them so the cathodes are common.
Anyway, some serious work going on there, nice job!

[Sinphaltimus]

Originally Posted by Daedalus

Hmmm... That's strange, since the ATX specification still requires 5V for standby power AFAIK. But even 3V should be doable with a diode, after all, 3V lithium cells through a diode work fine, just organise them so the cathodes are common.
Anyway, some serious work going on there, nice job!

No I was mistaken, my apologies. I had to revisit the diagram today and took notice that it was indeed 5v not 3v. I have no idea how my brain registered 3v before.


However; I've decided to leave it be. if my Amiga is till running during a time where CR batteries for it are cost prohibitive to its operation, I'll have it set clock via NNTP in the startup-sequence or roadshow or where ever that possibility hides. But thank you.

[Sinphaltimus]

I have another question for ya'll. Seeing as I'm going with an ATX PSU, do I still need to power the floppy drive via the Mainboard or can I just plug it into the PSU? I'm looking to avoid having to create a custom length power cable from the mainboard.

[Marlon_]

Originally Posted by Sinphaltimus

I have another question for ya'll. Seeing as I'm going with an ATX PSU, do I still need to power the floppy drive via the Mainboard or can I just plug it into the PSU? I'm looking to avoid having to create a custom length power cable from the mainboard.

You can plug it directly into the PSU. I do that on my A1200 with picoPSU.

[Sinphaltimus]

Originally Posted by Marlon_

You can plug it directly into the PSU. I do that on my A1200 with picoPSU.

Thanks, I'm being paranoid. Getting ready to start assembling everything this weekend and I don't want to cause any damage. I also didn't want to cannibalize my A500PSU since it works fine afaict. So I made my own Molex TO Amiga power connector adaptor. Did what this guy did - http://www.stone-oakvalley-studios.c...28072014005355

I have been checking continuity and voltage ratings like crazy these past few days. Measure twice, cut once.

I was looking at those Pico PSUs last week, those are pretty sweet. Great that they are small enough to fit inside Amiga cases.

[Marlon_]

I soldered my picoPSU wires to the bottom of the motherboard on the PSU connectors solder joints. That way I didn't have to have the pico PSU external, or bring a cable out.

[Amiga1992]

What are you planning to do with so many drive bays available? Tower is rather large.

[Sinphaltimus]

Originally Posted by Akira

What are you planning to do with so many drive bays available? Tower is rather large.

I have two external drives now. One was not working recently so i may swap the drive with my working internal.

The original plan was for Gotek +CD-ROM+External drive but I don't think I need a CD-Rom anymore, so GoTek plus 1 or two external drives.

Otherwise, I really don't have plans to put anything in there. But I have options. Possibly use SSDs instead of CFCards/SD cards.

I was even considering internal speakers at one point. I dunno really.

I chose the big tower because it looked most Amiga-ish of all the towers I have up in the attic. I have no issues with vertical, it's the horizontal I had issues with. I'd like to start bringing it to retro computer shows so maybe internal speakers and a build in display might be a thing next year or something. A complete standalone Amiga tower with everything needed to use it built in is something I've put on the back burner for now.

I still need to figure out a few things before it's up and operational again. I have a back plate I'm going to cut and rivet into place as a final step because I still haven't solved the HDMI port mounting issue. With the splitter installed, i can have two displays; one for presenting one for use or one for internal display one for external display.

I'll have a lot of this worked out this coming weekend. I figure another week or two and Phase one will be done. Phase two are ll the options I'm mulling over. In the meantime, I have more photos to upload so let me get to that. Should see them posted here within the hour. Nothing spectacular, I ditched my original power adaptor idea for a much better one I found online and I got the new power switch installed and working. That's about it for now. Work gets in the way of progress and I'm not typically in the mood after work. Because, well, it's just more work. On the weekends, it feels like a different story.

I'm open to ideas tho'. Nothing original about putting an A500 in a tower case I KNOW. But perhaps I can turn it into something no one has done before.....

[Sinphaltimus]

I could not bring myself to destroy my working A500 PSU. Besides, I amy want to sell it to raise funds for a Vampire Stand Alone. so I decided to make my own power adaptor. i decided to replicate this guy's method and I'm glad I did. http://www.stone-oakvalley-studios.c...28072014005355





Trying to keep the hot glue confined and close to usable.





Not too bad, filling in nicely.





This will work out just fine...





Aborted mission on the left, mission success on the right.





All connected up. I verifed pins and voltages and continuities and all that. Have not plugged it in to the Amiga yet. Not ready for that.... Still lot's of work to do.





And then this, Another custom adaptor for the power[IMG][/IMG] switch.





WE HAVE THE POWER!

[Sinphaltimus]

OK, not pretty, definitely made some mistakes but the PSU is mounted. When all is said and done, I plane to make a new backplate to cover the entire rear of the tower where big holes are and don't belong.




What ended up happening was, I made an assumption I would be able to mount the PSU flush left. But then the screw holes didn't line up so I had to move it to the right.


And then -

I was fortunate that the tower power led has 3 positions. So I moved the power led over to the center, remove the hdd led power lead over to the power led connector. Now I just have to combine the hdd led ground with the power led ground and I have my led connection all setup to connect to the Amiga keyboard pins.

Specifically pins:
8 - Floppy Activity.
7 - Power Status.
6 - Ground.

There is a second HDD LED in the tower that I plan to either connect to the CF Card Activity LED leads or run a fiber optic strand from the existing LED in to the socket where the second hdd led is. I haven't figured that out just yet.

A bit tired and not feeling like taking the soldering gear out right now, I'll finish this up tomorrow at some time.

With the progress I've made so far, I'll be ready to start mounting up the basics so I can test an external floppy drive I got on ebay (mine went bad). If it all works as expected I'll strip it down and get it ready to install inside the tower. TTFN.

[Sinphaltimus]

Well the ATX PSU is now showing issues. It's only giving me -8v on the -12v line. The Amiga is not into that at all. Time to start fishing for another ATX PSU.....

[Daedalus]

-8V on the -12V line won't stop an Amiga from working. What are the +5V and +12V lines showing? Perhaps there's a regulation issue? See if plugging in a dummy load helps - maybe a couple of old hard drives or something.

[Sinphaltimus]

Originally Posted by Daedalus

-8V on the -12V line won't stop an Amiga from working. What are the +5V and +12V lines showing? Perhaps there's a regulation issue? See if plugging in a dummy load helps - maybe a couple of old hard drives or something.

Thanks, I'll have to check these, been out of contact with my projects all day. Duly noted and will report back as soon as I can.

[Sinphaltimus]

Well, I didn't test anything. I was more concerned with the mainboard connected to metal screws and metal standoffs directly to the case. With the original plastic case the Amiga would be isolated so I decided to do something crazy and mount the bottom plastic part of the case in the tower first, then mount the mainboard to that.

I got a Blue Screen, so I resat a few custom chips and she fired up just fine.

Next steps are to connect the HDMI splitter, 512K trap door ram expansion and the two floppy drives (GoTek and External) then test again. Not going to do that tonight. I'm a bit tired and don't want to make any mistakes since this mean routing all the cables and mounting things permanently.

After I confirm the external floppy is working and the GoTek, I have to find 5.25" mounting rails for the GoTek and a way to mount the external Amiga floppy inside the floppy drive bay at the top of the case. I also need a 5.25" floppy faceplate. I know I have a few someplace. You think I'd have located one and put it aside when i gutted the basement a few months back. Nope. Now I gotta go searching around the attic for one.

But, she lives! So Happy! Almost there......

[Sinphaltimus]

OK, so yeas, i did get the Blue screen and I resat all my custom chips and it went away. Now the Blue Screen is back. Reseating the chips is not helping.

Can any of you suggest which chip is most likely the one I should focus on? I have no way of testing chips but if I have to buy sockets I will as long as I know which chip i need to be concerned with. I( don't think any went bad, I do think the sockets are old.