Amiga 600 schematics nearly put into Kicad

[kipper2k]

Originally Posted by rvctech

I've never had reliability issues with PLCC sockets that are correctly soldered. It would be a shame to solder down custom chips if you need to remove them later.

You probably already know this - but it's much easier to hand solder a PLCC socket if you cut out the base.

There are pros and cons to using PLCC sockets. The surface mount sockets are weak and will prevent any accelerators being mounted to the motherboard. Personally i would solder the CPU to the motherboard which will allow future use for any accelerator that uses a plcc format. Cutting the bottom off SMD PLCC sockets is good for chips that are not expected to be removed but for any possibility for A600 expansion you either need to solder the CPU to the motherboard or come up with some kind of adapter

[rvctech]

Originally Posted by kipper2k

There are pros and cons to using PLCC sockets. The surface mount sockets are weak and will prevent any accelerators being mounted to the motherboard. Personally i would solder the CPU to the motherboard which will allow future use for any accelerator that uses a plcc format. Cutting the bottom off SMD PLCC sockets is good for chips that are not expected to be removed but for any possibility for A600 expansion you either need to solder the CPU to the motherboard or come up with some kind of adapter

I was more referring to the custom chips, not the CPU.

Cutting the bottom off a PLCC socket makes it easier to solder by hand for prototypes. It weakens the socket but it's acceptable for a prototype and for testing.

[Mick]

Originally Posted by rvctech

I've been waiting to see your board come to life . Did Stedy end up performing any testing/investigation on it?

I'm not sure what is happening at this point, I told stedy not to bother if he doesn't want to waste time but he hasn't got back to me. People have busy lives. If a problem could have been found 2-3 months ago I could've fixed it and finalised the files but as it stands seems it's not working and nobody can tell me why. I'll probably just redo it using Gerbers save any differences in routing (trace lengths/widths etc).

[Stedy]

Originally Posted by Mick

I'm not sure what is happening at this point, I told stedy not to bother if he doesn't want to waste time but he hasn't got back to me. People have busy lives. If a problem could have been found 2-3 months ago I could've fixed it and finalised the files but as it stands seems it's not working and nobody can tell me why. I'll probably just redo it using Gerbers save any differences in routing (trace lengths/widths etc).

Build continued today, placed about another 100 discretes, topside nearly done, underside has maybe 100-200 more to go. Powered up the board as-is, nothing crazy happened, a good sign, power is getting to the correct points on the board

I'm going to finish this.

[Mick]

Cheers, I'd like to have some idea what went wrong if at all possible.

Just remember not to populate U49 (I don't think it ever was anyway) or the keyboard stuff I added in the box on the back, the SOT-23 footprints are wrong and VCC/GND reversed. None of them are necessary anyway just me being stupid, it's been quite a learning curve.

Is the oscillator output working do you know? even the 2A Gerbers have it connected to ground.

[Mick]

I've completed it just about.

[CD32Freak]

Looks great. Did you use the Gerber files I've converted from amigapcb.org? :-)
How did you export the drill holes from GerbView to PCBnew? I have no clue how to do that.

[Mick]

Of course, I wouldn't have been able to do it without you, not that Commodore'ish anyway.

I have done the A1200 1D1 too which was probably easier, on the A600 there were a lot more ground traces to not accidentally delete. I think I deleted something like 12000 on the A600.

I think to import the drill holes I just imported them to Gerbview and then exported the copper layers and they showed up (albeit as via's like everything else). You need to make footprints for everything including holes, the via's give you the precise locations of everything though.

If stedy wants to I'll get some of these made and we can just write off the old one, I'm still curious why it didn't work though it must be decoupling related I imagine. Although I did it the way most sources on the internet recommended (connected directly to ground plane) and Commodore did it the way they generally don't recommend (traces to IC), go figure. Maybe my signals were too clean or something. either that or it was me doing the the via's too small (0.3mm). I've just increased the sizes on this now.

[Mick]

Did you mean the via drills? I thought you meant the big holes. All of the via's showed as 0.4mm drill but you can tell which are the bigger ones by the copper diameter. They all had slightly different drill sizes etc so I've set them as 0.75/0.4 and 1.15/0.8.

[CD32Freak]

I mean, in GerbView you can import the DRL file with 'File / Open Excellon Drill File(s)' and open all the Gerber files, but when you choose 'Export to Pcbnew' you have to assign the layers. However, what layer do you have to choose for the DRL file

[Mick]

Yeah I just imported the drill file to Gerbview and then when I exported the other layers the drill locations showed up, I only really needed it for the 3 big hole locations I think everything else seemed to show up without it.

[Mick]

I spent days checking everything to be absolutely sure and then a day after ordering casually found a couple of missing ground links under U16 which will probably impact decoupling on it, they didn't show up in the high resolution the photo I had due to a shadow. I need to do the floppy holes slightly bigger too connector now doesn't fit, also need to check s-video port is in an okay location. It'd be nice to get a 2B board to check exactly what is going on under the memory and ROM but I think I figured it out. I added U49 the same as on 2D whatever the hell it's for. It's on 2 layers because it was cheaper and I'm told the original boards were 2 layer. Hopefully I'm getting close to the finishing line but depends if I can beg someone to spend the time testing it even though it has faults, if not I'll just post fixed files up but if you get a bunch of untested boards flooding Ebay don't blame me.




edit: floppy connector does go in but it requires a bit of pressure and is a tight fit, I thought it was strange as I followed Commodore on hole size.

[Mick]

As promised I've uploaded the latest files to the zone if anyone wants to order PCB's and give them a try or whatever. We'll all be dead at the rate things are going trying to ensure the board is tested prior to release. Again a lot of credit goes to CD32Freak for the work he did.

It's basically a copy of the rev. 2B board with cxa2075m/s-video and U49 added for t hose who want something close to the original boards for repairs etc, if it works I'm sure more knowledgeable people will be able to release different variations of it with extras added.

[Stedy]

Hi,

Mick has already seen this, current build status:

This was before I cleaned the boards, had some 'fun' soldering PLCCs but got there with some flux and hot air gun. Will re-check the solder joints and try powering up soon. Should have checked it tonight, ended up playing Mario Kart 8 online instead.

Agnus is missing from the kit of parts I was sent, working on getting another as I need it to get the CPU up and running. Connectors will get fitted if the basics work.

[rvctech]

Originally Posted by Stedy

Hi,

Mick has already seen this, current build status:

You ultimately chose not to use PLCC sockets?

[Mick]

Well I told him not to bother with it but it'd be nice to know what the reason for it not working was if at all possible, so I thank Stedy for his commitment to the cause.

Looking back the autorouting was a bit amateurish but this time last year I had no experience in PCB's at all. I've tried.

[CD32Freak]

Impressive, a new A600 baby from amigapcb.org files

[Mick]

Did you get the Agnus Stedy?

[Stedy]

Hi,

Yes, the Agnus chip arrived today. Will solder it in over the long weekend and start some tests.

@CD32freak

The design is inspired by the original files in terms of layout but the schematics and PCB have been redrawn.

[rvctech]

Originally Posted by Stedy

Hi,

@CD32freak

The design is inspired by the original files in terms of layout but the schematics and PCB have been redrawn.

This was the case for the original attempt which you are working on.

However Mick abandoned that version and started again with an import of the Rev 2A Gerbers that were generated from AmigaPCB.org. He modified this version to fix some errors and replace the video encoder, but it's basically that.

Happy to be corrected if I got it all wrong!