New A500+ kit available at A1k

[Tachyon]

So uh, Scrat, is there going to be another run of these boards?

[apex]

No, sorry. Problem are the missing parts. We reached now a point were spare parts are getting seldom.

[hese]

Finished my A500+ Project Red motherboard.



More pictures and full story on my Amiga 500+ Project Red thread.

If you have the motherboard PCB and are looking for someone to build it, I can do it for you. Just send me a PM.

[thgill]

Wish the bare PCB's were still available to purchase.

[demolition]

Originally Posted by apex

No, sorry. Problem are the missing parts. We reached now a point were spare parts are getting seldom.

I assume the hardest parts to get are the 23 pin and PSU connectors? I'm sure many people would like to be able to buy just the PCB with the common components and then they could source the few hard to get parts from somewhere else, e.g. from dead A500+ MBs.

Anyway, I also just finished my board.

Took quite a few hours but I also went slow and steady to avoid too many errors as there are a lot of components and it would be a nightmare trying to figure out if two caps had mistakenly been switched around.

I started by sorting out all the components in small marked bins, double-checking all the values. I then mounted the resistors first followed by the capacitors and then the ESR components. Thus, the smallest ones first. I did not solder any resistors in place until they were all mounted so I could make sure it all added up in the end. I just bent the pins and cut them to length. After adding all the small components, I fired up the soldering iron and fixed them in place.
I then proceeded with the bigger components, IC sockets and doing the connectors in the end. They had only supplied sockets for the large ICs, however I added turned pin sockets for all the smaller ICs as well.

Even though I tried to be careful, I still managed to make a few mistakes and on the first boot, the screen was just black. Turns out I was missing a resistor in the reset circuit so the reset signal was never released. Either the resistor was missing in my package or I dropped it somewhere or I would have noticed an extra resistor being left over. I checked the entire PCB making sure it was not soldered in the wrong place and it was nowhere to be found. Anyway, I fixed it and it still would not boot although the Reset signal was now looking good.. Then I found that the CPU clock signal was between 2.5V and 5V while the specs for the CPU says it should go below 0.8V and above 2V. I then found that one end of the resistor for Denise clk was soldered to Vcc via instead of its correct via 2 mm away, thus pulling up the clock signal towards Vcc. Fixing that, it booted up and so far I have been running memtest for 2 hours on 2MB chip without any issues, so it is looking great.

I have now also upgraded it with a Vampire as it deserves and now I need to do some more testing.

Edit: The board boots fine into my more or less fresh AKReal installation as seen on next pic, only modified to use RTG/HDMI in 1024x768.

[Mick]

Very nice demolition, all you need now is for A1200.net to make white A500 cases and keycaps. That would be glorious.

I take it kipper won't be making any then what with the shortage of parts?

[demolition]

Originally Posted by Mick

Very nice demolition, all you need now is for A1200.net to make white A500 cases and keycaps. That would be glorious.

I take it kipper won't be making any then what with the shortage of parts?

Keycaps are on the way and should not be too long, but no A500 case projects yet. Anyway, the case I installed it in looks almost mint, although I wouldn't mind a black case and keys.

Kipper2k did buy four kits AFAIK but I don't know if he will be keeping all four..

[Mick]

I wasn't knocking your case it's just that with A1200 cases being made new you'd expect A500 cases to be developed eventually as they've suffered a lot more with aging in general. A new motherboard inside a new case would be like having a brand new Amiga.

[apex]

A recapped Amiga 500 in a new case is the same. The soul is in the chipset and the new board just use the old chips.

[demolition]

Originally Posted by apex

A recapped Amiga 500 in a new case is the same. The soul is in the chipset and the new board just use the old chips.

Some of the chips can be found NOS, like the 010 CPU and CIA which is what I put in my board (the NOS CPU was then replaced with the Vampire which is surely new ). The custom chips are probably hard to find as new/NOS though. But yes, an old recapped and non-damaged A500+ board is basically the same, except for the board color. My old 500+s all have battery damage to some extent though and although it can be repaired, you'd have to be a wizard to make the repair invisible and have it look undamaged again.

[hese]

Originally Posted by Mick

Very nice

Thanks.

[Mick]

Originally Posted by hese

Thanks.

Yours is very nice too.

I was going to compliment it when I saw it later but I was too busy kicking myself for not buying a kit when I saw your generous offer to help build one for someone.

[Acill]

I just finished the first one of two I am building this weekend. Check it out.

Complete build progress and videos here: https://goo.gl/photos/d3xfSNepJpZMDGMk6

[obitus1990]

Looks like the first one has shown up on Fleabay...boards only for $150 euros. No parts. And, it looks like it was a German selling them...ironic.

[apex]

The guy doing this will be kicked out of the a1k community.

[Acill]

Originally Posted by apex

The guy doing this will be kicked out of the a1k community.

Sad he would do it! Lots of people wanting them and so few got the change. This is the part of Amiga I get the most bother about when I see profiteering!

[kolla]

Originally Posted by Mick

I wasn't knocking your case it's just that with A1200 cases being made new you'd expect A500 cases to be developed eventually as they've suffered a lot more with aging in general. A new motherboard inside a new case would be like having a brand new Amiga.

Well, is there anything preventing anyone from doing a new A500 motherboard that would fit in an A1200 case, apart from it being a heck lot of work re-routing everything?

Btw, does this A500+ board have any differences at all compared to the original A500+?

[demolition]

Originally Posted by kolla

Btw, does this A500+ board have any differences at all compared to the original A500+?

I can't say for sure it's the only difference but they have made a small change in the RTC battery charging circuit as rev 8B (which is what this one is called) will not charge the battery, thus it will work with a Lithium battery without a series diode.

[Mick]

I think they said it had black and white video output via composite as well? (might be wrong) still I'd love to buy one of these ready built.

Originally Posted by kolla

Well, is there anything preventing anyone from doing a new A500 motherboard that would fit in an A1200 case, apart from it being a heck lot of work re-routing everything?

Yeah that's a good idea actually but as an old A500+ owner the A500 case makes me feel all warm and fuzzy inside.

TBH I've been out of the Amiga scene for 20 years but after coming back and seeing all of the excellent home made hardware people have developed, I'm surprised there hasn't been more development around replacement motherboards for A500/A600/A1200 even if you have to source the custom chips yourself. I bought a pristine A600 that appears to have b0rked IDE due to capacitor leakage, my old beloved A500+ had long since been ravaged by the battery. It's all a bit of a lottery and you end up urinating money up the wall.

[demolition]

Originally Posted by Mick

I think they said it had black and white video output via composite as well? (might be wrong) still I'd love to buy one of these ready built.

The VIDIOT circuit is doing the RGB to Composite conversion and like in a normal A500/A500+, the standard circuit only creates a B/W output signal. They have however designed an upgraded VIDIOT which can do it in color just like the 600/1200. This circuit is not part of the mainboard though, so the color VIDIOT could also be used in a standard A500 if you wanted to upgrade its output to color (but who uses Composite nowadays except for testing in which case B/W is good enough? ).