ReAmiga 3000 post test run follow up

ReAmiga 3000 setup for a test run

You may have seen my previous post where I did a test run on my ReAmiga 3000 that I finished earlier this year. If not, check out my post about my ReA3000 that I built in April here.

While I did do a test run in DiagROM previously I did not have a daugherboard for it so I just whent through the usual tests (successfully) and called it a day. This time I did a more comprehensive test session where I tested a Amiga 3000 daughterboard, a BFG9060, a GottaGoFaZt3r 256MB Z3 memory card, programmed and replaced the logic chips and also replaced some ICs that I had to use adapters for previously.

Amiga 3000 daughterboard

Front of the Matze Amiga 3000 DB

While my ReAmiga 3000 started up fine in DiagROM it failed to run with a Kickstart rom. I was puzzled about this since it was running fine in DiagROM. No matter what I tried I ended up with a black screen. Problem was solved by adding the daughtercard. Now Kickstart boot screen came up.

Backside of the Matze A3000DB, here is where the I2C circuit resides

I am using a Matze A3000DB, more info on it here. This is just like a regular Amiga 3000 daughterboard but it also has I2C functionality so you can monitor temps. More info about I2C here, the added functionality is based on that project. So to be honest, I have not really fully understood I2C, perhaps I will do a deep dive in the future. I have an CPLDICY card I built last year and its neat to see temps. I am thinking this could be interesting to monitor if running a tight A3000 case with bad cooling.

Another note, this is a version of the Matze A3000DB with some added functions by kavanoz & CDH, see more here about this specific version of the daughterboard.

A GottaGoFaZt3r 256MB Z3 memory card was inserted and it was detected by DiagROM.

ReAmiga3000 + BFG9060 test, success?

The low profile heatsink/fan on the BFG9060 blows in the wrong direction, another thing to fix in the future…

Recently I built an A4000D that failed to run with a CPU card. That motivated me to test my older builds with a CPU card to make sure they work properly with a faster CPU. The only issue I had was to figure out how to jumper the motherboard, then it was smooth sailings.

68060 is detected in DiagROM (as is fast ram)

DiagROM identified the 060 and also the fast ram. Now I need to do a 6 hour fish render and stability will be tested (something to do for the future).

74FCT646 chip replacement

SOIC-24 to DIP adapters are the red mini PCBs. Also notice the original Commodore logic chips

If you look at the BOM for the ReAmiga 3000 you can see that Chucky recommends replacing the 74F646S with 74FCT646. Currently 74FCT646 can only be found in SOIC-24 from Mouser and Digikey and not in DIP so you need a SOIC-24 to DIP adapter to use them. While the adapter worked fine I just felt it would look better to run DIP chips instead. I had an UTsource order going for my A2386SX order in the pipeline so I added eleven 74FCT646 chips to that order from UTsource. Why 11 when the A3000 only needs 9? Well two of them is going to my A2386SX boards.

No more SOIC-24 adapters for a cleaner look!

The 74F646S chips actually runs hot, especially when there is 9 of them, that is something I noticed when using them from my donor machine. So it was a nobrainer to replace them with cooler running chips.

As I put in sockets for all the 74FCT646 chip adapters I am thinking of removing the sockets in the future and solder the chips directly to the motherboard for an even cleaner look. The ground plane in an A3000 is brutal though, not sure I wanna wrestle with this board desoldering stuff again. Desoldering the KEL 200 pin CPU slot was a nightmare.

Programmed and replaced logic chips

There are four logic chips on the Amiga 3000. About 15 years ago I had the oppportunity to buy a broken Amiga 3000 cheap because it had a broken display output. Turned out it was because one of the logic chips was broken, so it was an easy fix to just replace one of the chips with a new one.

So to future proof this ReAmiga 3000 build I replaced the logic chips I got from the donor A3000 with modern alternatives and got the JEDEC files to program them with from here.

Next step

I hope I can find a case for this build, they are difficult to come by but occasionally you can find one. Actually wish I had one now as I would like to set it up to a running system!

C’est la vie

ReAmiga 3000 motherboard is fully built and tested

ReAmiga 1.4 motherboardboard

I had an old Amiga 3000 in my stash that I got in a trade years ago. It was traded to me as fully working but never worked no matter what I did. When the ReAmiga 3000 project became known I wanted to save the broken A3000 by building up a ReAmiga 3000 motherboard with the parts from the broken Amiga 3000.

I did not have the soldering skills 15 years ago to do that, but today is a different time (and maybe I was better off 15 years ago with just one A1200 instead of a fleet of Amiga replicas today lol) – So the broken Amiga 3000, or at least what was left of it has gotten a new lease on its life!

Find out more about the ReAmiga project here.

I have already started soldering in stuff that I should have waited with, as usual it is difficult to wait for the right parts to arrive at the post office before starting the project properly.

So this is how it started out. This time I started off with a motherboard with all passives already mounted which saved a ton of time. Interestingly though, I found one error where the BOM specified a tantal capacitor, a regular ceramic cap was placed instead. It was an easy fix once I found a suitable component to replace it with!

Here is the original Amiga 3000 motherboard which acted as a donor card

The components I used from my broken Amiga 3000 was all the custom chips (more on that later), the special memory chips for the scandoubler and some odd pieces here and there such as the trim pot, power socket, disable switch for the scandoubler and the stacked female 25 pin port.

Most of this stuff can actually be found new. But I usually like to keep some parts from donor Amigas in new builds not just the custom chips for some weird reason.

Believe it or not, I actually used the same KEL connector for the CPU board that was soldered to the broken A3000. It was a painful experience desoldering it as it is soldered with 200 pins to the motherboard.

I also wanted to save the two edge card connectors for the daughterboard, desoldering them was a major hassle since the ground plane is very strong on the A3000. Instead I ordered replacements from AliExpress because they where extremely difficult to desolder.

Chipset gave me a surprise

As is de rigeur when building an Amiga replica, there are always some kind of surprises no matter how much prepping one does.

There are some very expensive chips on the Amiga 3000. First is the Amber chip which is part of the scandoubler/flickerfixer area of the A3000. Then there is the DMAC chip, both chips costs a ton of money to source if replacements are needed.

I did not know if these chips where working before starting the build and I was not prepared to pay 250-450+ euros for replacements if they did not work. Luckily, once I had the board fully built, I can now confirm they are working just fine!

But surprised I was, the Ramsey chip was broken. My ReAmiga 3000 would not start with my original Ramsey chip installed. Luckily I had a NOS Ramsey 07 chip in my stash that worked fine as a replacement.

And as lucky as I was, the same day, I noticed that a Buster 11 was offered for sale on a local website meaning I could skip the Buster 7 I had from the broken A3000. As it was offered on a local trading website I got it muuuch cheaper than from Ebay.

But…. I know what you are thinking, Super DMAC 02 and Ramsey 07, that is a recipe for trouble.

Lets find out if Ramsey 07 plays well with my revision 02 of the Super DMAC. I will just have to find out once system is fully up and running with Workbench installed. Then I will be able to do some stress testing. If problems occur, I will need to track down a Super DMAC replica.

Next steps….

Now all I am waiting for is a replica A3000D case to be available and I will order one in black ASAP. I am also doing a daughter board for it which I will post about later in the year here.