Tag Archives: GBA PII++

Amiga 2000 EATX

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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.

A500-GraKa GBAPII++ Amiga Graphics Card built and tested

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GBAPII++ Amiga graphics card

This is the second GBAPII++ Amiga graphics card I have built. I finished the last bit of the build two weeks ago. Today I tested it in my Denise Amiga clone and could confirm that it was working fine. If you are interesting in building one yourself, check out more information about the graphics card here. There are some details about the background of the card there too.

Hardware specs

The GBAPII++ is a Zorro 2 based Amiga graphics card based around the Cirrus Logic GD5434 chip. It has 2 MB memory and is a relatively affordable Amiga graphics card. Occasionally you see users referring to the card as an open Picasso 2 card as you can order empty PCBs yourself and build it. But if you know Amiga hardware well this card is based on another chip. The similarities are close though, both cards has only 2 MB and is probably likewise in performance as they are both Zorro 2.

The VGA adapter plate has both output and input so its possible to run scandoubler output through one VGA output, very handy and a must have these days IMHO. I use mine with a Indivision MK3 and it works perfectly out of box. Or run it with the Multivision-AGA scandoubler.

It is possible to use the card on an Amiga 500 by soldering an 86 pin 2.54mm edge card slot to the side of the card, thats probably why the graphics card goes by the name A500-GraKa.

Components

The graphics card is based on the Cirrus Logic GD5434 chip

If you are thinking about building one I suggest you go looking for a GD5434 chip first. These chips are not impossible to find but can be pricey. I have paid between 20 to 40 euro each for Cirrus Logic GD5434 chips (currently have built four cards based on this chip). Finding an old VGA card and desoldering a chip with hot air is also a possibility.

The memory used is the same type of memory that is used in an Amiga 1200 1.4d revision. The typical SOJ40 2MB memory chips in the quantity of 4 chips.

I had difficulty finding the correct voltage crystal but eventually found the right one on AliExpress (and it worked too).

Building the graphics card

For some reason I thought building this card was incredibly confusing. I think the main reason is that I somehow got the build instructions for a previous revision of the A500GraKa card, once I got the correct file everything worked out fine! IIRC there are some solder pads marked as ferrite beads that should take resistors (or it was the other way). To find out what components go where one can look into the designer files, also study the BOM.

Performance

The graphics card works especially fine in lower resolutions and fewer colors like this 800×600 8 color Workbench

I have not tested performance yet and will probably never do, but make no mistake, this is no competition for a ZZ9000 graphics card. It is a fine card to use on a 030 based Amiga with a Zorro 2 bus as long as one do not go crazy on the amount of colors or resolution used. It is much better than using hires laced. I stick to 800×600 in 8 colors and it works fine.

Conclusion

The graphics card is hooked up to the VGA adapter plate that is fitted to a3D printed bracket

Many thanks for the creators of this card and previous cards it is based on. I think this card is a no brainer, just get one if you have an empty Zorro slot and no graphics card. I will list the good things first and negative later, these are strictly my personal opinions.

Positive

  • Half size card
  • Has a hole cut out for your finger so you can remove it easely
  • Autoswitch between scandoubler/VGA
  • Open card, PCBs can be ordered by yourself. There is also commercial version of it
  • There is a thread on a1k.org where you can ask questions about the card
  • Supported in P96 (so you can install the card with the P96 installer)

Negative

  • Somewhat confusing build instructions
  • Only has 2 MB
  • Is a Zorro 2 card so its slow (but still perfectly fine for lower resolutions/fewer colors)
Here is Doom running on the GBAPII++ Amiga Graphics Card

New incoming Amiga PCB projects

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Here are some new Amiga PCBs for some new projects I got this week:

  • GottaGoFaZt3r memory card (will do the 256 MB version and probably a second card).
  • PiStorm16 x 2
  • Prometheus clone
  • MpegIt for the Prelude Amiga sound card
  • Prelude sound card PCB (not in the picture)

I also have two Amiga graphics cards in my todo list:

  • GBAPII++ graphics card
  • Mini GBAPII++ graphics card

And lets not forget the ReAmiga 3000 PCB I got late this week too! I have had a broken Amiga 3000D motherboard in my stash for years so finally I will be able to shake some life into it again!

So lets just say a massive BOM will be ordered soon!