Amiga 500 in ATX Tower case.

[Sinphaltimus]

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I regorganized my Facebook Photo Albums where many of the photos here were lined to.
So I bet many broke.
No worries, I put them all in one place right >>>HERE<<<
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Questions abound.

By now, many people have done this mod already but I rarely see the techno jargon I'm looking for in one place and I have some questions. I mean, back in the 90s I did it myself but I was helped by a lot of Amiga centric hardware that was easily available at the time. Today, not so much and I've lost most if not all the Amiga knowledge I've had.

First - the reason. My A500 case is so brittle that it is beginning to crumble in my very hands every time I have to open it up. That's it, no other reason. I don't want to spend $65 on a replacement case for it as i have so many parts and cases laying around here, I can do it at no cost except time spent.

I basically have 2 concerns.

First, the keyboard wiring. I'm thinking of using a PC keyboard cable, snipping it at both ends and using that to extend my Amiga keyboard cable. Basically snipping the Amiga cable in half so I have the proper connection on both ends. I don't suppose the keyboard cable would be longer than 2/3rds of a meter (aprox 2 feet at most). I do not know f a PC cable has enough wires in it but that's not a big deal I can use any readily available cable as long as the gauge isn't way off.

Any Caveats to this approach that anyone can think of?

I would like get the Amiga LEDs off the KB and on to the tower as well. Is there a way to do that direct from the mainboard as opposed to running wires back from the KB in to the tower? I'm looking at the pinouts here >><< and see Status LED but not drive access LED for the floppy. Or do I have it backwards? Or .. well yeah, can I run the power LED and the floppy activity LED straight from the mainboard keyboard connection?

My second concern is the edge expansion port. It's a 50 position 100 pin edge card connector for this correct? (http://classiccomputers.info/down/Co...anual_1987.pdf) I've about salvaging an old ISA slot which sounds appealing because I have parts. And my GVP SCSI controller has pins from each edge connection that I can slide a connector on to. Basically looking to make an adaptor with the 100 pin edge connector to the Amiga side and all the pins wired directly to male header pins using a single connector on each wire. Has anyone done something like this before?

And tricks or tips? Approximately, how long can I make this connection without worry? No more than 2 feet long because that's how tall my tower is so could I place the controller in an empty 5 1/4"bay?

Thanks in advance. I'm about 2 weeks out from starting this project. I'm just now starting to plan it out. I will fully document it and share the details here as I progress. A diary of the project so to speak. With lots of photos as well. Something I think is lacking and I'd be more than happy to contribute.

PS, I haven't decided if I want to keep the Original PSU or not. I don't see a point in destroying a perfectly good A00 PSU so I'm probably going to be mounting 3 PSUs in my case. The Original Maiga, The GVP one. I haven't made up my mind yet about doing the GVP power from Amiga mod. I think I may opt to do it because I won't be powering a hard drive with it, just a SCSI2SD adaptor. In which case I could probably tap the A500 power directly to supply power via the micro USB. Oh options, options options. And then there's my internal SCSI CD-Rom tht needs power, THAT will run off an ATX PSU. So yeah, I'll have at least 2 if not 3 power on switches that need to follow a specific order. Any ideas or advise in this area?


~Sin

[DamienD]

Hello there Sinphaltimus,

I hope you don't mind, but this thread is definitely better placed in the "support.Hardware" section

Our resident hardware legend "Jope" is in charge of this area and I'm sure can offer you great advise, not to mention the many other Amiga hardware geeks that regularly visit this section. You'll get greater coverage here

[Sinphaltimus]

Originally Posted by DamienD

Hello there Sinphaltimus,

I hope you don't mind, but this thread is definitely better placed in the "support.Hardware" section

Our resident hardware legend "Jope" is in charge of this area and I'm sure can offer you great advise, not to mention the many other Amiga hardware geeks that regularly visit this section. You'll get greater coverage here

My apologies for posting in the wrong area. Perhaps I can get an admin to move it? I don't mind at all, thanks for the help Damien.

Actually, if we could get this topic killed removed or otherwise locked, that's be great. I'm going to repost in the appropriate area.

[DamienD]

Originally Posted by Sinphaltimus

My apologies for posting in the wrong area.

No problem, it can be quite confusing as to which section to post your thread in order to get maximum coverage

Originally Posted by Sinphaltimus

Perhaps I can get an admin to move it? I don't mind at all, thanks for the help Damien.

Not sure I understand what you're requesting? I'm an admin and have already moved your original thread from "Amiga scene" to the "support.hardware" section

Originally Posted by Sinphaltimus

Actually, if we could get this topic killed removed or otherwise locked, that's be great. I'm going to repost in the appropriate area.

Ah, I can see you've now created a duplicate thread under "support.hardware" --> "Hardware mods".

Anyway, this thread now moved to the above and the other thread deleted

[Sinphaltimus]

Wow, I did not even notice your "Global Moderator" status. Well thank you again. I didn't realise it was moved already. Just kind of scatter brained at the moment.

[Jope]

Originally Posted by Sinphaltimus

First, the keyboard wiring. I'm thinking of using a PC keyboard cable, snipping it at both ends and using that to extend my Amiga keyboard cable. Basically snipping the Amiga cable in half so I have the proper connection on both ends. I don't suppose the keyboard cable would be longer than 2/3rds of a meter (aprox 2 feet at most). I do not know f a PC cable has enough wires in it but that's not a big deal I can use any readily available cable as long as the gauge isn't way off.

Any Caveats to this approach that anyone can think of?

No caveats, it will happily drive a 2 foot cable. The original cables are a bit longer.

I would like get the Amiga LEDs off the KB and on to the tower as well. Is there a way to do that direct from the mainboard as opposed to running wires back from the KB in to the tower? I'm looking at the pinouts here >><< and see Status LED but not drive access LED for the floppy. Or do I have it backwards? Or .. well yeah, can I run the power LED and the floppy activity LED straight from the mainboard keyboard connection?

Just take them from the mainboard keyboard connector. The two rightmost pins.

My second concern is the edge expansion port. It's a 50 position 100 pin edge card connector for this correct? (http://classiccomputers.info/down/Co...anual_1987.pdf) I've about salvaging an old ISA slot which sounds appealing because I have parts. And my GVP SCSI controller has pins from each edge connection that I can slide a connector on to. Basically looking to make an adaptor with the 100 pin edge connector to the Amiga side and all the pins wired directly to male header pins using a single connector on each wire. Has anyone done something like this before?

86 pins. If you are careful with the saw and choose a high quality glue, you can make a pretty neat connector yourself. The GVP's connector could also potentially be desoldered and you'd put in your sawed (+glued) vertical connector in its place.

And tricks or tips? Approximately, how long can I make this connection without worry? No more than 2 feet long because that's how tall my tower is so could I place the controller in an empty 5 1/4"bay?

I would lay the controller in the bottom of the tower at a 90 degree angle to the computer, then extend the SCSI bus instead.

PS, I haven't decided if I want to keep the Original PSU or not. I don't see a point in destroying a perfectly good A00 PSU so I'm probably going to be mounting 3 PSUs in my case. The Original Maiga, The GVP one. I haven't made up my mind yet about doing the GVP power from Amiga mod. I think I may opt to do it because I won't be powering a hard drive with it, just a SCSI2SD adaptor. In which case I could probably tap the A500 power directly to supply power via the micro USB. Oh options, options options. And then there's my internal SCSI CD-Rom tht needs power, THAT will run off an ATX PSU. So yeah, I'll have at least 2 if not 3 power on switches that need to follow a specific order. Any ideas or advise in this area?

Forget the original PSUs and use an ATX PSU that you wire to the Amiga and the GVP controller.

[Sinphaltimus]

Sweet. I don't think I have a scsi cable long enough to leave the controller at the bottom. I'll have to look around, but it has me thinking about something out of the ordinary. Flip the main board around and mount it to the tower side cover.

Thank you for all your answers, I will replace the original psu for both.

I will of course update this thread with all the details and photos as well.

[EugeneNine]

I was going to say 68 pins but its been a couple decades. They used to be a standard part that could be ordered from an electronics supplier.
The A2000 slots were 100 pin and were the same as the one in the 500 but with a few more power lines. I had made a backplane with the 86 (or 68) pin slot then a few 100 pin slots then the IBM ISA slots behind it like a 2000 and had my 500 board plugged into the backplane. I thought I had pictures of it but I bet they were old film pictures and probably in an old album at my parents house.

[pandy71]

If i can add my 2 cents then i would extend all outputs/inputs with small extenders to avoid heavy mechanical work (unless you have case modified for A500 MB).

[Sinphaltimus]

So, before I officially begin this project, I'm continuing with Prep Work.

And thanks to AmigaMech for talking me in to it. Step one is to see if I can get the ram working on this GVP controller I purchased years ago. It looked to be a botched repair job when I got it. I did try to de/re-solder but that wasn't good enough. I couldn't even get all these out of the controller after a clean de-solder. Came to find out, there were clumps of solder on the other side of the PCB. So this time, it's complete cleaning and replacement. If it doesn't work when I'm done, then nothing changes except my time and materials spent. Should be fun.



After some hi res scans (much higher res then shared here), I'm ready to identify the expected paths to test and identify any trace repairs or leaks I may need to deal with.







More as this story develops......

[mech]

The longer scsi cable will be fine as others have said.

86pin a500 edge connectors are available here:
http://www.electronicsurplus.com/eda...osition-86-pin
for $3.95 or so,no need to hack connectors up.

Don't use multiple power supplies, this can cause common ground issues. Use one psu.

Mech

[Sinphaltimus]

Originally Posted by mech

The longer scsi cable will be fine as others have said.

86pin a500 edge connectors are available here:
http://www.electronicsurplus.com/eda...osition-86-pin
for $3.95 or so,no need to hack connectors up.

Don't use multiple power supplies, this can cause common ground issues. Use one psu.

Mech

Awesome! Thanks again!

[Sinphaltimus]

If ISA is correct if hacked, isn't that a 0.74 thickness?

This connector is too narrow ".Accepts boards 0.054" to 0.07" thick" for the Amiga edge connection.

[Sinphaltimus]

This is the closest I've found to something I could use but it's$22 plus shipping http://www.surplussales.com/Computer.../con_edge.html

Scroll down to Texas Instruments Card Edge Connector
43 / 86 Contacts

[EugeneNine]

Looks like that size is still a standard stocked part but kind of pricey
http://www.mouser.com/Connectors/Car...y&Ns=Pricing|0

[mech]

Originally Posted by Sinphaltimus

If ISA is correct if hacked, isn't that a 0.74 thickness?

This connector is too narrow ".Accepts boards 0.054" to 0.07" thick" for the Amiga edge connection.

i am lost here, standard pcb is usually around .062"
????

many on ebay also:

http://www.ebay.com/sch/i.html?_odkw...ector&_sacat=0

isa connectors:
http://www.ebay.com/sch/i.html?_odkw...ector&_sacat=0

[Magic]

Originally Posted by mech

i am lost here, standard pcb is usually around .062"
????

I was thinking the same thing ??? I have never had a problem with PCB thickness regarding edge connectors. There is usually some tolerance built in.

[Sinphaltimus]

Maybe I'm mixing up thickness with centerline numbers? Not sure because it's not always clear in item descriptions. But it's definitely a concern. ISA and PCi are definitely different thicknesses where you can fit pci thick card in an isa slot but not the other way around so there are thickness issues to consider. ISA looks about right but that green connector looks way too narrow compared. can see it in the difference between the TI 86/100 connector and that other one. They are definitely for different pcb thickness. I just want to be certain before buying connectors.

[Sinphaltimus]

Lastly, this might be a moot point now. I got my Super Denise and installed it, decided to put the system back together and see if my VGA adaptor works but I was met with an unpleasant surprise. My GVP impact series II is reporting a multitude of "gvpscsi.device unexpected status" errors and refuses to boot.

I already searched this like crazy and nothing I found helps because it all has to do with SCSI termination and bad cables. But by board does this with nothing connected to it as well. Once SCSI device, 4 SCSI devices, No SCSI devices, all the same thing.

The only difference is the memory slots were removed. (the jumpers are correct for 0MB). I don't know if that would cause this but I don't think so. it doesn't make sense.

So without a hard disk controller this project and my Amiga are dead in the water.

I would need a replacement SCSI controller or other solution (CF anyone) - however, those items seem impossible to find for the A500 at a reasonable price.

I'll check back once in a while but my short lived reintroduction to Amiga life has just hit a brick wall I'm not sure I'm ready to do anything about. Seriously considering selling everything that works at this point.

I put the OCS Denise back just in case and same issue.

I might box it up until such a time as I can acquire an eprom burner and I'll try putting the last firmware update on it see if that fixes anything as a last ditch effort before throwing in the towel.

In case any of you trouble shooter feel like giving it a go, it's an imapact series 200 A500HD+ rev6

[Sinphaltimus]

OK, This project got put on hold because I screwed up my PROM chip when I plugged in the SCSI connector backwards.

However, I can confirm after purchasing an eprom programmer and the correct eprom, my SCSI controller is back in action. So I will most likely resume this project this weekend.

First thing is to try and get the ram sockets working on the SCSI controller again (right now it only works as a SCSI controller without ram).

I have a technical question however; and for that I will start a new topic elsewhere.