New SMD A500 and A1000 motherboard partially assembled
 

Hi All,


i did post some info in other thread on the a500 FPGA accelerator thread but i don't want to hijack the that thread so i am creating this.

I have redone the A500 motherboard. (as have many before me) I redone the board from scratch rather than try to update someone else"s design. I didnt use Kicad as i hate it :). here is a quick picture...

http://kipper2k.com/_temp/a500smdtop800.png

The board is in the mail to me and i still don't know if i have messed up anywhere yet.

The board is based on a project created by "Red Keg Technologies) and i have changed and added a few things.

some of its features are ;

-built in Gotek with OSD support.
-DF0/DF1 switch over
- mono/composite/Svideo selectable output (PAL/NTSC)
- choice of Agnus to allow all versions of A500 on the 1 motherboard
- single 2MB ram that will replace the older RAM.
- Header for Devs to access all signals from Denise to make video addons
- Single 12v power supply using a standard 2.1mm barrel connector
- 2.5mm stereo audio jack
- complete with V3 Video hybrid (fully built)

i prob forgot a few things, i'll add more info as i remember.

I will ask someone to sell them as i will not do it myself. I think the nicest thing about this is that the board will be pre assembled and all the old through hole components are gone. There will be very few components to solder to complete the board and it will not take long. The cost to build is a lot lower than using the older through hole components.

I have also reworked the A1000 motherboard with the same features. It is currently 99% complete waiting for the a500 version to be completed and tested first. No pictures of this till the a500 is done

(picture shown is not the final version)

Simply brilliant!

Here is a picture of the boards i just received. You can see what components are actually on the board before i need to add the remainder.

http://www.kipper2k.com/_temp/betaboard_800.jpg

and supersize here

The components are tiny, tough to see lol. There are a few that i need to add by hand as the higher wattage rated components weren't available. It comes in many colours as long as it's green lol

Very impressive. These days I am more of an A600 fan due to the form factor even thyback in the day the A500 was what I grew up with. This project with all its quality of life improvements built in is making me reevaluate my snobbery.

I think I am going to need to see who your sellers are going to be.

Will this have jumpers on it to easily reconfigure the Fat Agnus to support 1MB CHIP RAM from the trapdoor? Or to switch it from NTSC to PAL? (i.e. make it dead simple to do the mods that normally require cutting traces or soldering pads)

Very nice. What's the kind of price of getting something like that made over just a PCB?

I'd been idly contemplating designing an ATX form factor A500+ and frankly having tried it in the past I really don't fancy doing SMT soldering.

the board has already 2Mb on it...

Wow, that is fantastic. Looks beautiful. Looking forward to hearing more about this as you test it.

I will tell you, the Amiga community is BRILLIANT!

So the board will come pre-soldered with SMD resistors, just need to add bigger SMD components?

Anyway, how much?

That is an awesome project. Nice work! I can really appreciate the built-in gotek support.

But, a comment, if I may...If I were to design an Amiga replacement board, I would ditch the DB23 floppy and video connector. I get it. That's "original", but since you can't get DB23 connectors, it would make more sense to implement a commonly available connector as an alternative. Or somehow have the option to install either original or alternative connector. Having that option would make it far easier to attach video adapters and hook up gotek drives externally. I'm thinking in cases where you may not have a donor board.

Anyhow, carry on. Nice work!

Not many logic board replacements excite me, but this looks pretty neat. I am especially piqued by the A1000 board. Can't wait to see the goodies packed onto it. While not so excited about the Gotek (I still like working with real floppies,) I think that is pretty awesome.

Hi kipper2k,

Impressive project. What EDA did you use?

Monitoring this thread, I'm very interested by this!

Hi,

I used Eagle 8.0 and seeing as no one else appeared to use it i done from scratch. it took about 300 man hours to get it up to beta status so it was pretty involved.

ATM i am not in good shape, both knees are refusing to work so until i find out what is going on i have to take it very easy. One of those things that has been getting progressively worse over the last 5 months and i finally risked going to th hospital as Covid apears to be a little more quiet now. I am now at the mercy of waiting for a specialist

Get well Kipper.

Kipper this is brilliant! Those small caps/resistors really put me off, I can solder but nowhere near that level of competency it would drive me insane lol.

I am impressed with the A500 board because of:

Both agnus chip types on the board, being able to pick is great!
The floppy emulator on board is brilliant! I assume I can still have the old-school floppy drive stacked on top and choose which to boot from?
Looks like 3.5 audio jack and rca plugs so both options - excellent!

All I need to source is the bigger stuff, sockets, ports etc. I can solder that no problem.

I would love different colours but green is old-school so no problems :)

Oh and hope you get well soon :)

Thanks for the kind words, here is update, i haven't played too much in the last couple of weeks. I had a weird issue that was preventing boot. Diagrom would load and then crash continuously, not always at the same time/point.

After days of checking/rechecking i found the issue i had connected IPL0 and IPL2 backwards.

Here is current status...

onboard gotek works, EON demo works (you can use a std floppy drive as df0 if you wish
Composite/Svideo works
2MB ram installed (8375 Agnus), shows 1MB, not sure why not 2MB
snap off video hybrid works ok

here is my cost so far (my cost not bloated)

5 boards partially assembled delivered including customs $300 CAD (total cost for 5)

remaining components/parts from digikey approx $35 CAD. (per board)

if you use a meanwell psu then ~$30CAD (+12v, -12v, 5v)

if you use the onboard buck cct (+12v, -12v, 5v approx $15 CAD. You will need to use a 12V desktop type PSU at least 4A

I have updated/made a few cosmetic changes to the A1kSMD mobo and will order that one next once i have some cash available. The price for the A1k version should be roughly the same

Very cool project! Looking forward to more.

Just want to jump in with the crowd and say that this is impressive and I certainly think I would like to get one of these when they become generally available.

Very nice!

Can you share detail of the header for video connection - I guess that means a simple plug in board for video rather than a reversed or interposing socket on Lisa?