Monthly Archives: October 2025

ReAmiga 3000 post test run follow up

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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…

Motorola MC68040RC25 CPU (02E42K)

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I got this Motorola 68040 25MHz CPU recently for a great price. It was too cheap not to buy. Interestingly, it is a later generation of the chip, manufactured in 1995 (or later). The 68040 is famous for being a hot chip. I remember that too well from running one in my Amiga 4000D I had back in 1998. But these later generations are made with a smaller manufacturer process, 0.65 micron vs 0.8 micron, so it should run cooler than the CPU on that crazy hot running Commodore 3640 CPU card I had.

I have not decided what to do with the 68040 CPU yet, for example, I have an old Apollo 1260 sans CPU that I could convert back to an 1240 and sell for 1999 euro on Amibay. While that is tempting, I think I would want to run this one in one of my big box Amigas instead as I am curious if it is overclockable and how hot it runs. I am also curious if the performance from the 040 CPU would be satisfying.

One irritating thing is that it has this silly flat and round aluminium heatsink glued on to it. Tried to remove it but it is bonded to it and wont move a micron. I was thinking of prying it off with a chisel and sledgehammer but got the idea to use fishing line or dental floss instead. No matter what option I take this pathetic heatsink will be removed one way or another and be replaced with a bad-ass P1 cooler with a Noctua fan. Maybe I have to spend a week grinding it off with my trusty Dremel from 1997 (hope not).

DIP to PLCC Amiga chip adapters

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DIP to PLCC adapters for Amiga computer chips

I have had these DIP to PLCC adapter kits in my stash for quite a while, today I finally gave in and built them. They are usefull if you want to use PLCC Amiga CIA chips instead of DIP CIA chips and for using an PLCC Motorola 68000 CPU instead of a more common DIP 68000.

Commodore Amiga 8520 CIA PLCC to DIP adapter

These 8520 PLCC to DIP adapters has just been washed after being built.

Amiga 600, 1200 and 4000 uses PLCC 8520 CIA chips, these chips can be used on Amiga 500, 2000 and Amiga 3000 (I guess on the A1000 too) with a DIP to PLCC adapter. In my experience it is actually cheaper to get a real DIP 8520 instead of using an adapter and a PLCC CIA for Amiga computers that can use them as they are a bit more expensive on the market. But if you are like me and have a stash of 100 PLCC CIA chips then you gotta do what you gotta do (obvious joke).

Motorola 68000 PLCC to DIP adapter

PLCC 68000 CPU is not that common but it is used in the Amiga 600 (and IIRC in the Atari ST). You can run one in an Amiga 500 and Amiga 2000 with a DIP to PLCC adapter. Why would you want to run a PLCC 68k CPU instead of the DIP Motorola 68000 CPU? No idea, but it looks cool.

Build tips for PLCC to DIP adapters

  1. Do the pinstrip first by soldering two legs on each side only and making sure the pinstrip is straight, you can also fit the pinstrips in a socket. Then solder down all the legs.
  2. Cut off the upper pins that will sit under the PLCC socket with a sharp cutting tool. Cut them off as close to the PCB as possible.
  3. Then solder the PLCC socket, use flux to make sure solder does not short legs outs.

Good luck!