1. What is the MiSTer?
To start with, let me give a brief overview of the MiSTer project. To put it in context, let’s briefly explore the options for enjoying a 1980’s computer platform in 2020.
The purist approach is to use original hardware. This may or may not be available to you: if you don’t still have your original Amiga 500 or Commodore 64 such popular machines are readily available second hand, but prices are increasing. Once you have one, maintaining this old hardware can be a problem. Electrolytic capacitors leak and need replacing. Leaking batteries that haven’t been removed from machines like the A500+ can destroy the whole board. Original magnetic media (cassettes and floppy disks) are rotting and becoming increasingly unreliable. Original C64 power supplies are ticking time bombs.
There are other practical aspects. These old computer/keyboard combos are big units and take up a lot of desk space. A bigger problem associated with running these machines today is the monitor. If you have your original CRT monitor and it still works then you have a problem free, authentic experience; but now that desk space demand is really getting onerous. If you want to use a more modern monitor then there are some hoops you have to jump through, and if you want your picture to be accurate, of high quality and free of any game-killing added latency, they can be moderately expensive hoops. Grappling with these problems associated with the original hardware is the price you have to pay if you want to take the purist approach.
There are many concessions you can make with these machines if you are a little less purist, such as video output mods to work with modern machines, the addition of accelerators and hard drives to machines which never had that capability, attachments to allow the use of modern input devices, and so on. However, if you want the easiest time you can go to the opposite end of the purity scale and get your fix via emulation, which in this context is using software to enable one computer system to behave like another. The price you pay for simplicity is authenticity (of course) as well as accuracy and speed, as well as the more ineffable ‘feel’ (which we will discuss more as we go on).
The simplest approach to emulation is to use the Windows PC you may well be using to read this webpage. I was adequately emulating Commodore 64’s and Amigas on a Windows machine 20 years ago and the state of play today for emulating machines such as these is really rather excellent. A step back towards the purity end of the scale involved replacing the Windows PC with a dedicated emulation machine, and the Raspberry Pi is well supported and a popular choice. Until recently I had a dedicated Raspberry Pi on my desk that was my Amiga, and booted seamlessly into an Amiga Workbench. I also have one of the excellent Deluxe Controllers from Monster Joysticks. The joystick is a genuine Sanwa stick and buttons, and a Pi can be mounted in the shell for a portable all-in-one. With the Retropie software this is a fantastic solution for emulating a huge range of systems.
In recent years, a new middle-ground has opened up between original hardware and software emulation, via the use of Field Programmable Gate Arrays (FPGAs) to simulate original hardware. In brief terms, an FPGA is an integrated circuit (IC) consisting of logic blocks that can be reconfigured by the user. An FPGA of sufficient size can therefore in principle be configured to behave like another IC of fixed design. So if we take a Commodore Amiga as an example, I cannot build a brand new Amiga today using only off-the-shelf parts, since the magic of that machine came from the custom chipset (Agnus, Denise, Paula…) which were only ever manufactured in the Commodore fab. However, since the layouts of those chips are well known, they can be replicated in their entirety in the FPGA. If you do this for the entire Amiga architecture, what you have is to all intents and purposes an Amiga that is functionally identical to the original. Just one that you can turn at a push of a button into a Commodore 64, or any other machine you can replicate in the FPGA.
There’s lots of fun to be had arguing over whether doing this is still emulation, if semantic arguments is what you thrill to. It’s not software emulation, but it is hardware emulation. However hardware emulation via FPGA effectively negates the disadvantages of software emulation, and so it’s imprecise to use the same ’emulation’ term to describe both. The reproduction of the hardware can be super accurate and super fast, so there are none of the latency issues which plague software emulation. The result is a ‘feel’ which is super-authentic and, for me, indistinguishable from original hardware. This is a subjective argument, similar to the vinyl argument deployed by many old audiophiles, but it has to be experienced to be understood. The experience of capturing the feel of those old systems is just magic on an FPGA based device.
One very successful implementation of an FPGA device for simulation retro machines is the MiST project. This was a single device for which a wide variety of different ‘cores’ have been developed, with each core replicating a different machine. The initial focus of the project was the AMiga and the Atari ST, hence the name. That’s pretty much all I know about MiST: while many people still use it today it has been effectively superseded in popularity by MiSTer, a project which evolved out of MiST.
MiSTer is an open source project, and its creator and main driving force is Alexey Melnikov. The key to the project is that it is based around a widely available FPGA development board: the Terasic DE-10 Nano. The Intel Cyclone V FPGA chip on this board is much more powerful than the FPGA used for MiST, but the board itself is extremely cheap, since it is intended primarily as a learning tool and is heavily subsidised to that end. The DE-10 Nano kit works out to be cheaper by quite a large margin than buying a bare Cyclone V chip! The board also has an ARM processor, and the MiSTer implementation uses both chips. The system cores run on the FPGA, while a barebones Linux runs on the ARM side and manages interfaces to USB, ethernet, HDMI and so on. The resulting package is an incredibly fast and authentic retro experience supplemented by all the modern luxuries you could want. It’s a fantastic piece of work and continues to improve day to day, both in terms of the underlying software implementations as well as the range and accuracy of the computer, console and arcade cores which are available.
So that’s a brief summary of the road to MiSTer. In the next piece, I will give an overview of the basic MiSTer system I’ve been running for the past 8 months.