An Interview With Valentin Angelovski
It's been a couple of years since I've been on irc.rubbermallet.org, and I got to know one very unique person there whose name is Valentin Angelovski.
Valentin lives in Australia where a mob of kangaroos crosses the boundless open of the mainland. He has Slavic roots, but English is his native language.
This article is an interview with Valentin about his homebrew device of a Flea86.
Over here - in Russia, - we have a term of "downgrade" which supposes the use of older computers and software for solving different tasks in modern times. In the English-speaking countries, I haven't met such a sense of this word. Probably, "retrocomputing" (http://en.wikipedia.org/wiki/Retrocomputing) is the most close word to the Russian "downgrade". A person who is into retrocomputing is accordingly called a retrocomputing hobbyist.
Valentin Angelovski is such a person.
Let's find out more about his interesting product by asking him some questions.
Me:
Had there been any prerequisites for the Flea86 before you started to develop it? Maybe, you were inspired by some similar device you'd seen before?
Valentin:
Flea86 as an actual project officially began life around mid-2009 as a personal challenge. Around that time I was using the very-popular DOSBox PC emulator and recall being very impressed with it - so impressed in fact that I wondered if I could (using my embedded programming skills alone) write my own emulator from scratch and make it run on very low-cost hardware with minimal resources. Flea86 would not have been possible for me without a very good understanding of both the 8052 microcontroller as well as the IBM-PC's internal architecture.
Me:
In a few words, what is the Flea86? And what can it do?
Valentin:
Flea86 is a 16-bit x86 emulator that is designed to run on very modern variants of the Intel 8052 microcontroller. The emulator specifically targets the very quick (and 8052-compatible) Appotech AX-2005 processor, though simplified builds of the emulator can be made to run on any 8052 with sufficient RAM and ROM.
Flea86 uses various boolean-processing methods (also known as 'bit-banging' in the embedded programming world) on the 8051 controller to implement the basic PC system elements i.e. CPU/BIOS, 8253/8259, PS/2 Keyboard/mouse, SD card, DRAM controller and VGA video output - all handled by a single processor core with no other hardware support!
Me:
Why "flea"? :)
Valentin:
Good question! My project was originally called 'DX-demo' (a play on 386-DX computer I used to own, but that was only meant to be a temporary name). Finally the day came when the project was almost complete, I wanted to call it something more meaningful and so Flea it became :)
Me:
The motherboard of the Flea86 was made very neatly, judging by the photos. I saw some homebrew x86 compatible devices with tons of wires. Can you share your secret: what helps you soldering so good?
Valentin:
Sure! Several things helped to make Flea86 a well-presented design.
1) Design of a Printed Circuit Board (PCB) with a clear well-thought layout.
2) Because Flea86 boards are all hand-made, I use the 'Drag-soldering' method for the board assembly. This produces very neat soldering and even works well with many (but not all) types of complex surface-mounted components.
3) Desoldering wick and an optical magnifier are essential tools for cleanup of any potential electrical short circuits caused by poor solder flows etc.
Me:
The Flea86 is a bare board, and it's sensitive to electrostatic discharge. Did you think of making some case for it to protect it from the "outer" environment?
Valentin:
Although the Flea86 system board is actually quite a rugged unit, it was intended to be sold as a fully-enclosed system.
Due to the high manufacturing cost of the custom enclosures (Approximately USD$130 per case for low production quantity!), I have decided to delay the production of the custom cases until a cheaper solution can be found.
Me:
Do you do mass production of the Flea86, or is this on a case-by-case basis?
Valentin:
Currently, Flea86 systems are hand-assembled in very low quantity due to the problems arising from the high cost of the custom cases as I mentioned previously.
Me:
Do you produce it for money or for free? How can anyone order the one for personal usage?
Valentin:
Whilst I do not make Flea86 boards for free, I do believe that I charge a reasonable price for them :) Pricing for a base-model Flea86 system board without on-board slave USB port is currently USD$60, whilst USB-equipped versions are USD$75. Pricing is subject to availability as stocks are very limited. Interested readers are encouraged to visit my www.fleasystems.com website and email me using the contact details located on the site.
Me:
How long have you been working on your Flea86 project?
Valentin:
From a development point-of-view, I worked on Flea86 part-time for roughly around two and a half years (ie. from June 2009 to january 2012, part-time).
Me:
Valentin, are you aware of a Raspberry Pi, Arduino and some other single-board computers (SBCs)? And if yes, do you know any other 8086-compatible SBCs?
Valentin:
Yes, I am aware of those systems and many more like them! As for homebrew x86-powered SBC's, there are various projects built around legacy parts (ie. Sergey Kiselev's Xi-8088 system) or more modern FPGA hardware (ie. Zet x86 System-On-Chip).
Me:
Any ideas for the future about the Flea86?
Valentin:
Well, I recently completed testing of a Flea86-to-ISA Bus bridgeboard option:
allowing for some nice expansion possibilities with Flea86.
Hopefully, by the time this interview goes to print, I will have released some Flea86 schematics/sourcecode for interested hobbyists and hackers to experiment with. Beyond that I am open to any suggestions or ideas :)
Me:
What else projects have you been working on?
Valentin:
I am also currently working on related project called Fleatiny, which is intended to be a 100% open-source design:
Fleatiny is intended to be a much smaller/simpler design than Flea86, except Fleatiny runs a compact language interpreter (Tiny-BASIC variant) instead of a custom PC emulator :) Several versions of Fleatiny are currently under development, in both microcontroller and FPGA-based variants. Further details about my homebrew projects can be found at www.fleasystems.com.
Me:
Thank you very much for the interview, Valentin!
Valentin:
You're very welcome!
The interview was conducted by Artem Efremov specially for "The Downgrade" magazine.
Created January 22-nd, 2013
[Russian version (русская версия)]