Agon light™ is a fully open-source 8-bit microcomputer and microcontroller in one small, low-cost board,
built with state-of-the-art 21st-century technology. It has two claims to fame, both of which are
substantiated in the next sections. In a nutshell,
Agon light™ is the fastest and cheapest 8-bit microcomputer ever made.
In addition,
Agon light™ is the world's sole standalone, instant-on, BASIC-programmed microcontroller
that dispenses with a host PC and sketch compilation.
This allows projects to be controlled from the immediacy of a BASIC interpreter's prompt.
The illustration below details Agon light™'s key technical specifications.
Agon light™ is a true 8-bit microcomputer in that there are no FPGAs and no emulation in it.
It also has no layers of abstraction such as virtual machines. The bare metal is exposed directly
to the firmware programmer.
As a microcomputer, Agon light™ has VGA resolution of up to 640 x 480 pixels and 64 simultaneous
colors. It supports sprites and scores best in all popular microcomputer benchmarks by a large
margin (see the "Benchmarks" section below).
As a microcontroller, Agon light™ has a control port featuring SPI, I2C, 20 distinct GPIOs
(including UART lines), a system clock output, as well as power (3.3V and 5V) and ground rails.
It also features a separate ACCESS.bus header.
Much more information about Agon light™ can be found in the
Hardware Manual.
For firmware and software information, check out the
Agon WiKi.
Demonstration
The video below contains an extensive demonstration of Agon light™'s BASIC capabilities,
as well as an accessible overview of the system.
A follow-up demonstration, discussing Agon light's game programming capabilities and
the Olimex version of Agon light, is also available:
Unique Selling Points
The fastest and cheapest 8-bit microcomputer ever made, by a large margin.
No host PC or sketch compilation required to control your projects: you can control your whole house from
the immediacy of interpreted BASIC commands.
A hardware canvas for you to make of it your own dream, customized microcomputer, with your own preferred
look-and-feel and functionality. Agon is a laboratory for computer science experimentation.
No more assembly programming to customize or personalize your computer's firmware: Agon light™'s entire
firmware suite, including the functionality of the Video Display Processor (VDP), is programmed in C with
freely available tooling (compilers, IDEs, loaders, etc.).
Agon™ is an open-hardware and open-source project through and through, so you get all the information about
the system.
Benchmarks
The figure below shows Agon light™'s raw performance (in seconds to completion) in the Rugg/Feldman benchmarks,
compared to the performance of other machines running the same benchmarks with essentially the same BASIC interpreter.
Rugg/Feldman benchmarks, raw results without normalization.
To compare the architectures while taking the clock speed out of the equation, the next figure shows the same benchmark
results now normalized for clock frequency. In other words, the results below can be interpreted as the relative
performance of each machine when they all run at the same clock speed.
Rugg/Feldman benchmarks, now normalized for clock speed.
In all results above, Agon light™ is the best performing machine. To illustrate its advantage over other systems at a glance,
the following picture shows the speed-up factor (rounded to the closest integer) of Agon light™ relative to the other
machines, for each of the Rugg/Feldman benchmarks. On the top table, raw performance numbers without normalization were
used to calculate the speed-up factors. On the bottom table, performance results normalized for clock speed were used.
Agon light™'s speed-up factor with respect to other systems, for each of the Rugg/Feldman benchmarks. The table on the
top is based on raw performance numbers without normalization. The table on the bottom is based on performance results
normalized for clock speed. All speed-up factors were rounded to the closest integer.
Another popular benchmark for 8-bit machines is Noel's Retro Lab's BASIC benchmark. The figure below shows all results of
that benchmark available at the time of this writing, including Agon light™'s performance (namely, 1.8s to complete the
benchmark). Agon light™ is almost a factor of 3 faster than the next best machine.
Noel's Retro Lab's BASIC benchmark results, including Agon light™'s performance (1.8 second) at the very bottom of the plot.
Finally, one more BASIC benchmark is often used today: Matt Heffernan's “Battle Royale.” The table below summarizes all
known results next to Agon light™'s own performance, which is more than a factor of 3 faster than the next entry, and almost a
factor of 5 faster than the best-performing real machine.
Matt Hefferman's "Battle Royale" benchmark, including Agon light™'s performance.
Manufacturing Costs
At PCBWay, in volumes of 100 boards, the cost of the original board is $46 (PCB plus SMD-only assembly, including the cost of
the SMD parts). For higher volumes, the cost decreases appreciably. Only the through-hole components are missing, but anyone
can buy and solder them for well under $10 extra. Therefore, we can say that, for relatively low production volumes in the low
hundreds, the total costs for the bill of materials and assembly is about $50 for an original Agon light™ unit (significantly
less for Olimex's lower-cost version).
We can compare this to the estimated manufacturing costs of the historically lowest-cost 8-bit computer before Agon light™:
Sinclair's ZX81. We know that it sold for £70 in 1981. Assuming that Sinclair had 40% gross margins (which is unrealistic,
but safe to assume for our purposes), it would have cost £42 to make. In today's money, that is £165, or $187: over 3.7x
more expensive than Agon light™.
Keep in mind, however, that regardless of the seller, there are other costs involved if you want to purchase a complete and
tested unit delivered to your doorstep: margins, taxes, shipping and import fees, etc. All design and manufacturing files
are already available on Github.
Firmware
Agon light™'s official firmware has been written by Dean Belfield, with contributions by Jeroen Venema and others.
It consists of three main parts:
Quark™ VDP: the code that runs on Agon light™'s
Video Display Processor.
Quark™ MOS: the machine's basic operating system,
akin to DOS and CP/M.
Quark™ BBC BASIC: an extended version of
Acorn's classic BASIC interpreter, with graphics and control extensions specific to Agon light™.
There is also the Quark™ MOS firmware update utility.
This allows users to update/change the firmware of the eZ80 CPU without the need to have a Zilog USB
Smart Cable to do so.
Moreover, there is now a software suite that allows you to flash the eZ80's firmware for the first time
without the Zilog Smart Cable. In addition, if you bricked your Agon during firmware experimentation, you can
also unbrick it with this tool, again without the cable. See
Agon Electron HAL,
Agon Electron Flash, and
Agon ZDI Load. Here is
a video illustrating the process,
by Jeroen Venema.
Agon light™'s BASIC interpreter has a built-in (inline) assembler. But if you want to natively code in eZ80 assembly,
we offer an even better option with this
improved native Agon light™ assembler by Jeroen Venema.
Now, since Agon™ is a fully open-source platform, others have been busy creating their own firmware and ports. Koen van Nieuwehoven,
for instance, has ported CP/M
(a specific version of the VPD firmware is also needed):
There is now an Agon light emulator
available, which enables software development even for those who haven't got the hardware yet.
The eZ80 development environment of TI calculators (CE C/C++ toolchain) has now also been
ported to Agon light™.
Architecture
Agon light™'s architecture takes inspiration from the classical mainframe + terminal structure. Its 'mainframe' or processor subsystem
includes the CPU proper (an eZ80 running at 18.432 MHz), system memory (parallel SRAM, 512KB), a µSD-card slot and several
general-purpose I/O lines. The 'terminal' or Audio/Video subsystem contains an ESP32-PICO-D4 system-on-a-chip running at 240 MHz,
8MB of memory (pSRAM) and ports for video (VGA), audio and keyboard (PS/2). Agon™ takes 5V input power either from its USB or GPIO port.
Agon light™'s CPU is an eZ80 pipelined core, compatible with the classical Z80 but much faster and more efficient on a MHz-per-MHz basis,
and featuring a 24-bit address bus capable of directly addressing up to 16MB of memory and I/O.
Flexibility
The two main subsystems that constitute Agon light™ (namely, the eZ80 processor subsystem and the ESP32 A/V 'terminal') can be
programmed in standard C with freely-available tools, such as the Arduino IDE and Zilog's ZDS-II IDE. This means that Agon light™
is essentially a hardware platform, built for maximum flexibility, that allows you to make of it your own dream, personal,
customized computer, according to your own vision of what a computer should look, feel and do.
Instead of having to program kernel code in assembly so to write to an EPROM, you can simply write C code, compile it with free tools,
and upload your firmware into the eZ80's and the ESP32's embedded flash memories. You have full control not only of the basic
functionality of Agon light™, but also of the look-and-feel the user experiences upon turning the machine on. You can brand it yourself
and show your dream computer to your friends. In a sense, Agon light™ is a laboratory for computer science experimentation.
Join Us!
TODO: Other pages for repository links, where to buy, etc.
Rugg/Feldman benchmarks, raw results without normalization.
Rugg/Feldman benchmarks, now normalized for clock speed.
Agon light™'s speed-up factor with respect to other systems, for each of the Rugg/Feldman benchmarks. The table on the
top is based on raw performance numbers without normalization. The table on the bottom is based on performance results
normalized for clock speed. All speed-up factors were rounded to the closest integer.
Noel's Retro Lab's BASIC benchmark results, including Agon light™'s performance (1.8 second) at the very bottom of the plot.
Matt Hefferman's "Battle Royale" benchmark, including Agon light™'s performance.
Agon light™'s high-level system diagram.
