Amiga 600 schematics nearly put into Kicad

[kipper2k]

Originally Posted by alenppc

That board looks gorgeous. One thing that could potentially be useful is to replace the SMD 68k with an A500 dip one so we can solder accelerators directly instead of the 68k, but not sure if there is space for that.

if 2 x 32 pin headers can be added to this board then the expansion options for this will be unbelievable. It will open it up to a wealth of options. Assembling this would not be on my wishlist as the options are very limited with just a plcc socket for a cpu

If i knew kicad i would add it myself but my Cad tool of choice is Eagle and there is no available conversion tool


edit: there is a way i can do it make it good for all types of accelerators (one in particular

[alenppc]

Originally Posted by kipper2k

(one in particular

Yes the TF536

[kipper2k]

Originally Posted by alenppc

Yes the TF536

there wont be no room for that, will need something a lot smaller in physical size .

i'll use one of my working a600's as a prototype, if it works on that then it should work on these boards

[Lemaru]

Kludge already has an adaptor that works with most cards that has been tested with it, Including the TF536 (needs a layout change to make it fit though). I'm going to design my own adaptor for something I have in mind when I get some time

https://www.exxoshost.co.uk/forum/vi...t=1489&start=0

[alenppc]

I don’t want to derail this thread too much but just to say that it would be easier without adapters, since they simply add to the instability sitting on top of a plcc cpu and then you have another board sitting on top of that, see what I mean?

[kipper2k]

It looks like i will make a bastardized board and remove the ROM and CPU footprint and then make something so that it will accept an accelerator that has the capabilities of booting. Obviously i will make it available for everyone once proven. I do not like plcc adapters at all i have had my fill of them

[Mick]

At this point I've removed everything apart from the (necessary) video DAC and s-video mod, no point adding loads of stuff if the basic things aren't working. I'm even considering just routing power/ground the same as Commodore did on 2 layers as I'm sure converting to 4 layers/power planes is what has screwed things up if anything, I didn't want to do that though because A1200 has planes and I won't know what I'm doing. I'll wait to see to what stedy says he's busy atm so not rushing him.

One thing I'm wondering is what should be used for copper clearance in the planes? kicad default is about 0.5mm which seems a lot, with all of the via's there's massive holes everywhere.

[Mick]

If I can get this working and did another version would a PGA footprint be better? if I did that though could do with finding another solution for the keyboard controller.

[Stedy]

Hi,

I plan to start construction on the first board this week. Will be doing it in a staged process, checking some continuity on the power traces as I go so that if it breaks at a certain point, I'll know why. I won't be using sockets as they are unreliable as hell. I must make sure my solder joints are good though and use plenty of flux!

I have ideas how to enhance the design but baby steps.

[arananet]

One cool addon could be the possibility to add plcc tht sockets instead of smd ones. it will help to test and replace the customs chips. Just like Jeroen from the a1200+ has made on his project. Also adding a clockport on the mobo it should not be too much difficult. Even replace the edge connector with a pci one to have all the required signals to make an accelerator that will not popup anymore from the cpu socket, just like Kipper had made on his adapter (a1200 to pci connector) will a huge plus, the only problem will be rounting all the signals to that location.

Keep with the good work, I got a few dead a600 mobos corroed by acid that could be revived with this.

Edu.

[Mick]

I think some of the standard kicad footprints were for industry so they might be difficult to hand solder. I recently changed them.

Originally Posted by Stedy

I have ideas how to enhance the design but baby steps.

I do too, get it working.

When I manually routed all of the signals were routed correctly but there's just the couple of mistakes I mentioned on those boards. I think any issue will be down to me adding power planes thinking that it would just work (and be better).

[Mick]

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[kipper2k]

Originally Posted by Mick

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Mick, its not too late, can you add 4 small holes through the motherboard around the CPU so that if someone wants to clamp down a plcc on top then they can get a good connection. make the holes 1.8 - 2mm wide. Just place a plcc socket around the cpu footprint to see best place to put them

[Mick]

How do the holes help? by warping the board slightly under pressure? or are you going to make accelerators with the same mounting holes? thing is it's kind of pointless doing anything that the original boards didn't have because any hardware made will be built with the original boards in mind. It's like that resistor which I moved looks good on paper but those who sell accelerators will still have to grind out a bit off the socket for compatibility with the original boards so ultimately is there any point? at this point I just want to find out why it isn't working, I'm not really learning anything otherwise and there's no point adding anything like holes if it doesn't even work.

[Lemaru]

I like the idea of the holes to hold stuff down on the PLCC, but a decent socket does the job to be honest.

Once it's working then if the plan is still to stick it on GitHub or somewhere then people can make all the changes they desire.

[kipper2k]

yes, the idea would be to allow future accelerators be it plcc or other adapter boards to sit on top of the cpu, One thing for sure if it is not done then it will be harder to make the clip on boards hold. There are pages and pages of people complaining about their PLCC sockets that do not hold.

Originally Posted by Mick

How do the holes help? by warping the board slightly under pressure? or are you going to make accelerators with the same mounting holes? thing is it's kind of pointless doing anything that the original boards didn't have because any hardware made will be built with the original boards in mind. It's like that resistor which I moved looks good on paper but those who sell accelerators will still have to grind out a bit off the socket for compatibility with the original boards so ultimately is there any point? at this point I just want to find out why it isn't working, I'm not really learning anything otherwise and there's no point adding anything like holes if it doesn't even work.

[Mick]

I'll see about it but I'll probably be redoing the A600 board anyway if I can sort this:





I combined my schematics with CD32Freak's Gerbers, had to make all new footprints though.

Routing sucks so let Commodore do it for me.

Live to win!

[Mick]

CD32Freak deserves a lot of credit for this, I'll be able to do more or less an exact replica of the A600 2A with the newer DAC and S-Video. A1200 errors seem to mainly clearance issues around the through hole stuff, the only connection error I've found is that the PWR_BAD resistor (R918) was connected to vcc rather than ground but that looks to be a mistake in the amigawiki schematics. I don't think the clock will work anyway since Commodore did a 20pin foot print and the datasheets I've looked at show the RTC to be 18 pin? I could fix that but I've seen a thread on here with someone claiming to have fitted the chip and it worked so. :

I've told stedy not to bother checking the old board if he doesn't want to waste time although I'm still wondering why it didn't work, one thing I noticed with the A1200 is the copper plane clearance is about half as big as the Kicad default I used.

[rvctech]

Originally Posted by Mick

CD32Freak deserves a lot of credit for this, I'll be able to do more or less an exact replica of the A600 2A with the newer DAC and S-Video.

Hi Mick,

Have you ever seen an A600 Rev 2A publically released? I've been wondering whether there was something wrong with it, because the earliest Rev 2 that I can can see anywhere is Rev 2B.

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

I generated a replica of the A600 Rev 2A during my Christmas break using the original Commodore data (AmigaPCB) after CD32freak dropped some CD32 hints in Nov ;-). I had no intention to do anything with it, since I'm using it as a proof of concept for a different project. I kind of think that the board might not work anyway, and I don't have a Rev 2B to compare it to. Maybe I should make one and see if this revision even works at all?? Or if someone has a Rev 2B it would be good to compare. I already found one track on the Rev 2A that was 'fixed' in Rev 2B but I don't think it would have a big impact (see attachment).

[rvctech]

Originally Posted by Stedy

Hi,

I plan to start construction on the first board this week. Will be doing it in a staged process, checking some continuity on the power traces as I go so that if it breaks at a certain point, I'll know why. I won't be using sockets as they are unreliable as hell. I must make sure my solder joints are good though and use plenty of flux!

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.