Månadsarkiv: april 2025

Amiga 2000 EATX

Publicerat av

I just finished the last touches on my Amiga 2000 EATX build. The Amiga 2000 EATX is a clone of the Amiga 2000 motherboard in an extended ATX format. That means it will fit inside most ATX tower cases that can swallow a larger EATX format (or in this case can be hacked to accept EATX motherboards). You can read more about the A2000 EATX here.

I like to modernise the Amiga systems I have so I look forward installing an Amiga in a generic PC tower, with that said, I actually think the original Commodore Amiga 2000 case was awesome. It was an easy case to open up to have access to the slots, it was also a good looking case and the de facto professional Amiga to have back in the day.

I like to think that the A2000 EATX continues that professional legacy of the Amiga 2000 by modernising it and making it more accessible and user friendly.

Building an Amiga 2000 EATX motherboard

My Amiga 2000 EATX in about 85% built state.

As you can see on the picture, most of the features of a genuine Commodore Amiga 2000 is present on the A2000 EATX motherboard.

Although the motherboard above is in a half finished state above we can see there are space for five Zorro 2 slots, three ISA slots (one less than on a real A2000), the CPU slot and the video slot. Also note the ATX power and space for all custom chips from an Amiga.

I used the chipset from an Amiga 500 and then got a Bluster chip (Buster clone). I also took the vidiot from a broken A500. It is possible to run both 8375 and 8372. I did not have an 8375 so I used an 8372 instead. Having the option to chose between 8375 and 8372 is awesome – 8375 is more difficult to find and more expensive. There is also provision for a PCB to generate the tick signal. I do not have that on this build but if needed could be added.

The most difficult part to solder on this project is the chip memory which is very fine pitched (if unexperienced). There are also two diodes (IIRC) that have tiny solder pads, other than that it is very straight forward.

Here is the backside of the motherboard.

I also want to shine a light onto the documentation around this project. The amount of documentation on the project website is extensive and very well done. There is also a Discord where one can ask questions if one gets stuck.

Chosing a case for the A2000 EATX motherboard

The specific chassi I am using for this project is called the IT-2812 Business by Inter-Tech. Here is a link to the exact chassi. I did extensive research before ordering it so I was sure the extended ATX motherboard would be able to fit inside it. I was prepared to mod the case to get it to fit which I eventually had to do.

You can make out where I had to cut the case to make the motherboard (and CPU/Zorro cards) fit the case

While it looks great and fits the motherboard, after some extensive case cutting, I do not recommend this case at all since it is made of very thin sheet metal. While thin sheet metal is great for modding, it also makes for a seriously flimsy case (I bet its more flimsy than a MicroniK plastic A1200 tower).

Modding the case involved cutting off sections from the front of the chassis. While these modifications was simple, it was difficult to do it without access to power tools. So it does not have that professional look.

But as a proof of concept, it is possible to fit an EATX motherboard inside a regular ATX case (this case was not meant to be used for EATX boards). Although I have to be careful when inserting Zorro cards since there is no support for the front most part of the case, there is nothing to screw it down into. I will probably find a sturdier case in the future.

What kind of hardware to put into the Amiga 2000 clone?

What use is a bunch of Zorro slots if there are no hardware attached to them. Amiga 2000, no matter if it is a clone or the real deal , is a workstation so it has to have some muscles packed into it. Here is what is plugged into them and the other slots at the moment.

n2630 CPU card

The author of the Amiga 2000 EATX motherboard has designed a turbo card for the A2000 also, it is the n2630 and is a 030 50 Mhz based turbo card with IDE and a CF slot on board. You can also fit an FPU and various amounts of fast mem. I think this card is a nice compliment to the A2000 EATX and it was a no brainer to go with this card. I just wish I went for 256 MB fast memory instead of 128. Maybe next time…

I do wish there would be a DIY 060 card for the Amiga 2000 CPU slot. 030 is fine, but a fast 040 or 060 is better once you have gotten used to it (if you wish to stay in real 68k land).

Prelude replica sound card

Prelude replica Zorro 2 16-bit sound card with Mpegit module attached to it

I had an extra Prelude replica that I had built so that card went into this build. It has the MpegIt addon added to it making it possible to play MP3s fine on a lowly 030 Amiga.

A500-Graka graphics card

Here is the Matze Amiga graphics card

There is a Matze graphics card running in the computer. I think this is a nice card to run in a Zorro 2 based Amiga.

Multivision 2000 scandoubler

And then for scandoubling duties I have an old classic piece of hi-end Amiga hardware, the 3-state MultiVision 2000 scandoubler for the A2000. It is running great in the A2000 EATX and produces a nice image on my TFT.

Other bits

I have a Zorro-LAN-IDE card that will go into this case once I have a bracket made for it. There is also a 80 mm Noctua fan at the back that is mated with an old Zalman fan mate I had in my stash to quiten it down.

Finishing touches, the ATX backplate

I found the file to print the ATX backplate on a1k.org. So I sent it to JLC to get it printed.

And here it is installed. Instantly makes the Amiga 2000 EATX looks better from the backside.

Conclusion

I am very happy with the Amiga 2000 EATX. It was a great experience to build it and I have had a lot of fun seting up the whole system. I also thoroughly enjoy using it!

This is not my main Amiga but I use it a lot during testing of Zorro cards. It has proved to be very reliable and a great addition to my stable of Amigas. I would not mind running it as a daily driver if it had a faster CPU.

ReAmiga 3000 motherboard is fully built and tested

Publicerat av
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.

FlashROM 40 & 42 pin Kickstart Flash EPROM

Publicerat av
A weekends work resulted in 17 FlashROMs – this is actually the second batch I have made for myself

There are a couple of different hardware Kickstart solutions for the Amiga. The most proven one seems to be 27C400 chips that you can program in a T48 (with an adapter) and erase with UV light. If you buy a Kickstart from a retailer, that chip is probably an 27C400 EPROM. I dont like the UV light eraser, and the 27C400/27C800 chips are expensive, so I went looking for another solution that had the possibility to scale up in volume fine.

I don’t know what it is about burning Kickstarts for the Amiga but the topic is highly confusing at first. Not only do you have to have the correct byte swapped file (or build the ROM file correct if you want to run a custom ROM) but you need some kind of adapter to be able to program some of the solutions on modern cheap programmers.

This is not a tutorial in how to burn a Kickstart or how to build your own Kickstart, I suggest you schedule a weekend to do a deep dive into that topic. Then it sort of makes sense (I think).

No doubt in the future something like the KickSmash will probably be the defacto standard and I contemplated ordering a batch of PCBs and building a suite of KickSmashes for my fleet of Amigas. Instead I went with the FlashROM, because right here and now, it is possible to run FlashROM on all Amiga models while the KickSmash fits the Amiga 1200, Amiga 3000 and Amiga 4000 (and A4000T).

With new Kickstart ROMs being released fairly regularly these days. And the need to be able to build your own Kickstart so you can f.e. add ehide.device for a TF1260 system or PeterKs Icon library to the Kickstart, an easy way of updating Kickstart is IMHO, a must have, these days!

What is the FlashROM?

The FlashROM is basically a Kickstart replacement that you can program yourself – FlashROM has 1024 KB of space, meaning it can take two Kickstart files. This is great as it is possible to run one Kickstart ROM and one DiagROM rom on the same chip.

You change what bank you want to be active by setting a jumper on the pinouts between GND and A18.

If you do not need dual ROM functionality, just concatenate the same ROM twice and flash it to the EPROM.

Programming a Kickstart to the FlashROM

I use a T48 to program chips, an adapter was needed to be able to flash a Kickstart ROM to the FlashROM. I actually chickened out and just ordered a ready made programmer to reduce the complexity of this project, you can find out more information about the FlashROM adapter on Levo’s website.

Using the adapter is a breeze, just have to connect the wires correct and everything works just like programming any other chip. Erasing the EPROM is no different.

40 pin FlashROM

40 pin FlashROM, I notice it was not cleaned properly as you can see flux residue left at the top left corner

Here is the 40 pin FlashROM, this will go into my Amiga 500, Amiga 2000 and Amiga 4000 and so on.

42 pin FlashROM

42 pin FlashROM for my Amiga computers that can take a 42 pin Kickstart chip (such as Amiga 1200)

Here is the 42 pin FlashROM, this will go into my Amiga Denise clone, Amiga 4000TX and Amiga 1200. One benefit of running it in a ReAmiga 1200 is that the jumper on the motherboard select which bank you want to be active.