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an unofficial site for Dennis van Weeren's Minimig - an open source modern implementation of an Amiga

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ACube Minimig v1.1
Released February 2008
Reviewed by straycat March 2008

Those of us of a certain age may remember an age before the PC. A time when floppy disks ruled and viruses were something merely caught by swapping disks with friends and colleagues. Before the internet took hold most of us had to wait for our monthly fix of news and software from magazines. Times have moved on and and while magazines and floppy disks still exist there's something more reminiscent of the Amiga's heyday. Back then their custom chips left the competition standing and the passion for these machines remains today in a small but active community. 

Amigas have moved on since the halcyon days of the early 90s, despite hardware and OS setbacks in recent years. Modern Amigas offer most of things we expect today but the classic Amiga 500 is all you need to access a vast slice of the best games written for the Amiga.

After a few years in development the Minimig has emerged as a open source implementation of an Amiga 500. Primarily the work one one man Dennis van Weeren the Minimig attempts to shrink an A500 into a board so small it can be designed to fit in a CD jewel case. There's tiny 68k processor and ram chips on the board, along with an FPGA chip programmed to do the work of the Amiga's custom chips.

The Minimig is available from several sources including the manufacturers, ACube themselves. I ordered from Amigakit based in the UK. Delivery was fast - next day and well packaged too. Opening the outer packaging revealed a large, heavy power supply  and the Minimig itself in a surprisingly small, light weight box. The power supply is an optional extra from Amigakit, if you have the right adapter you might be able to use something you already own.

The ACube production of the Minimig comes in a nice box with a manual, very professional indeed

Inside the box is a Minimig manual and the board itself in an anti-static padded bag. The manual isn't extensive but contains enough key information to get your Minimig working. Surprisingly Amigakit do not include a memory card, something ACube seem to sell with the board on their website. To be fair to Amigakit it clearly states at the checkout a memory card isn't included. A quick rummage around my old mobile phones reveals a spare MMC card that turned out to work fine.

The board is surprisingly small and fits nicely into the palm of my hand. It's a packed board with things of interest on all four sides. At the 'front' there's an SD/MMC card slot and a button on the board to bring up an on screen menu (more on that later). The Minimig reads ADF disk images from SD cards in the same way the Windows emulator WinUAE does, essentially making the SD card a replacement for a floppy drive. The Minimig also loads the Kickstart from here - unlike traditional Amigas that include them on a Rom chip.

Moving around the side of the board there's keyboard & mouse connectors and a reset button on the board. Around the back there's a VGA output, audio out and serial connector. The last side of the board has two 9 pin connectors for Amiga style joysticks so you can use your classic controllers.

There's some preparation work before you can get your teeth into the Amiga classics. You're going to need a keyboard and mouse (standard PC with PS2 connectors), some speakers if you want sound, a monitor and a joystick for most games. You'll soon be wondering about what to put the board into. At the time of writing are no official cases from ACube and being a non-standard board it does make things a bit tricky. There's some long threads in the Amiga forums about different case ideas, it's worth taking a look for some inspiration. If you don't fancy building your own the closest we've come to a standard case so far is the plexiglass housing by Wizard66. The case provides the Minimig adequate housing and lets you see view the inners and get to the on board reset and menu buttons.

Once you've prepared an SD card you'll need to copy some essential files to it. Apart from your favourite Amiga programs you'll need the firmware and Kickstart files. The firmware file is available to download several sites including ACube. Unfortunately Kickstarts are still licenced so you need to own your own Amiga to use it file on your Minimig. You can also buy Kickstart chips from most of the Amiga resellers. Once you've copied your essential files to your card you can start copy some ADF files. If you have your own traditional Amiga you can create your own ADF files for many disks although there's a heck of a lot available to download from the internet. Remember copyright still applies to most games and programs so stick to Public Domain software if you do not own the originals.

Update: I've heard from good sources Cloanto's Amiga Forever Kickstart Roms can also be used although I've not tested!

The Minimig is very much 'in progress' and at the time of writing the official firmware from ACube will only work on a handful of LCD monitors. Already someone has pre-released a firmware to allow the Minimig to be used with virtually all LCD monitors. From my testing this works very well. Expect to see plenty more firmware updates to improve the Minimig in the future.

Minimig in a simple but effective sandwich case

Once you've plugged in your Minimig the power will come on - glowing LEDs on the board indicate power (Incidentally there's no power switch on the Minimig so you're forced to turn off at the mains rather reminiscent of the early Sinclair computers). The Minimig decrunches the Kickstart in the recognisable multi-coloured lines associated with loading Amiga software before being greeted with the Amiga Kickstart screen. According to the Minimig Wiki most Kickstart versions have been tested from v1.2 up to v3.1 - I've stuck with v1.3 so far, probably the most common Kickstart associated with the Amiga 500.

Loading an Amiga program involves accessing the on screen display by pressing F12 on the keyboard, or alternatively pressing the button on the Minimig board. You're presented with an very simple menu of your ADF files which unfortunately are restricted to names of 8 characters and files are listed in the order you copied them to the card rather than alphabetical. Minor issues and probably something that can be improved with an updated firmware later.

Once you've selected your program it should start loading in very much the same way as a floppy disk but without the noisy drive access of course! Loading time is pretty much the same as loading from a floppy and you'll be forced to switch disks if necessary by accessing the on screen menu. Unfortunately the Minimig only recreates DF0 at the moment so if you're playing a game needing a lot of disk swaps you'll find yourself accessing the menu quite a bit. It's not perfect but it's yet another thing I think we'll see in a firmware update.

The current firmware means you might be doing a fair bit of disk swapping for some programs

Of the games I've tested so far there's been a significant number of games that haven't worked or are hampered by bugs. The bugs vary from not loading at all to minor graphics issues that do not significantly affect the game. Despite a number of big games that do not work the majority do, you can find an on-going list of the Minimig Wiki which you're welcomed to contribute to. Whether you see these issues as a major flaw in the Minimig or incidental really depends on your standpoint. If you're looking for a very high level of compatibility then the Minimig in it's current state can't match something like WinUAE. If however you see the Minimig more as an on-going open source hardware project owned by the Amiga community it's value is more extensive. Many of my favourites worked during my testing including North and South, Gauntlet 2 and Sensible Soccer. It's claimed on the Minimig Wiki that Turrican works but my ADF didn't. It's worth baring in mind ADFs can be the culprit as well as incompatibility with the Minimig, so if in doubt try another ADF. In many cases the games are perfect. Nebulus and Marble Madness play at perfect speed and the graphics look great. Speed is usually spot on although New Zealand Story not only had graphics issues but timing problems too. Rainbow Islands runs perfectly, a joy to play on the Minimig. Captain Blood plays fine except for a graphics issue with the pointer and Sensible Soccer v1.0 works great although there are faint vertical lines down the pitch.

I couldn't drag myself away from North and South!

Compatibility is really hit and miss although the problems tend to be with the more graphically intensive games. Applications are generally a good bet. Deluxe Paint 3 works great, as does Sonic Drumkit, Amiga Basic and Amiga Explorer which I'll come to in a bit.  I've yet to try the Amos designer but several Amos creations have failed due to the mouse being uncontrollable. Amos is well documented for utilising the custom chips in a particular way which probably accounts for the problems.

Rainbow Islands - a real classic on the Minimig

There's one other firmware issue to mention - the Minimig firmware cannot write the SD card. This isn't a hardware or ADF issue, it's just the firmware can't manage it at the moment. Again, expect to see this changed in due course. Over the course of this review I have mentioned a number of firmware related issues and while many if not all of these can be fixed/improved they have yet to be done. Being an open source project and without a big company behind development there's no guarantees we'll see these improvements. Then again Amiga users will be no strangers to companies letting them down and the community driving the Minimig might just work to it's advantage. Cloanto's Amiga Explorer is something I've been using frequently on my traditional Amiga and I'm pleased to say it works fine with the Minimig. You can transfer files from the Amiga Ram disk and vice versa, ideal for saving your DPaint creations until we see write access to the SD card. As well as Amiga Explorer software you'll need a null modem cable and a PC with a serial port.

Technical Specs:

Processor Freescale MC68SEC000
Ram 2MB, 1.5MB available to user (0.5MB used by Kickstart)
I/O Keyboard & Mouse (PS2)
2 x Amiga style joystick ports
Serial Port (9 pin)
VGA out
Audio out
Media SD/MMC card

For a more extensive list of specs see the Minimig Wiki

Summary:

The Positives

The Negatives

- Potentially it's a very small, portable Amiga, an ideal A500/A600 replacement.
- Use modern peripherals that can easily be swapped and changed.
- It's new hardware to replace/compliment your aging retro Amigas, and the only 'new Amiga' available at the moment.
- Use real Amiga joysticks.
- Timing and graphics are excellent in the games that work.
- Compared to UAE there's no Windows boot time, losing a layer of emulation.
- Firmware updates are easy to apply to the Minimig.
- Be a part of the Amiga community bringing new hardware to the scene.
- It's just fun to use!

 

- Currently only DF0 drive, no write access to the SD card, the video output need improvements and the on screen display could be better, although all these can be addressed in firmware updates.
- Compatibility is weak compared to WinUAE, some major titles just do not work at the moment.
- If you just want to play games WinUAE is a much cheaper option.
- No official case available at present.
- No power switch on the Minimig.
- There's other modern classic Amigas in the pipeline including the NatAmi although they are some way off from materialising as a consumer product.

 

Links:

www.acube-systems.com Homepage of the Minimig manufacturer
http://www.opencircuits.com/Minimig_Project The Minimig wiki including software compatibility list
www.amigakit.com Amigakit, UK Minimig supplier
http://home.hetnet.nl/~weeren001/ Dennis Van Weeren's homepage, creator of the Minimig

 

 

 

 


Website by straycat 2008. Disclaimer applies. Minimig is an Open Source project.
Amiga, the Boing Ball and other assorted pieces are trademark Amiga Incorporated.

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