My blog
12-SEP-2024
Get ready for a blast from the past! Join me at the World of Retrocomputing exhibition this weekend, September 14-15, 2024, at 8 Queen Street North, Kitchener, ON, N2H 2G8, Canada. I'll be showcasing my three different FPGA-based ZX Spectrum 128K designs. Explore the fascinating history of computing, predating the Internet era, and discover the pioneering tech that shaped our digital world. Admission is FREE! Come meet me and experience the nostalgia-filled exhibition. Details of my ZX-Spectrum implementation are here and of course, I'll be glad if you
11-SEP-2024
Preparing for an exhibition, getting everything in one place...
- Yes, everything I made, which includes part of the FPGA code written by me, Arduino Loader (written by me in full) and PC tool (written by me in full) are open source and presented here https://alxlabs.ca/speccy.php
- There were three projects, code from which was used by me, everything which is taken from those must be treated according to the conditions authors used
- Special thanks to Devic Goran for his version of aZ80, see https://opencores.org/projects/a-z80
- Special thanks to Wallner, Daniel and MikeJ for their version of T80
https://opencores.org/projects/t80 - Special thanks to Matthew Hagerty for his version of YM-2149 (AY-3-8913) Complex Sound Generator, https://github.com/dnotq/ym2149_audio
Things I did not make and those are not open source:
- ZX Spectrum 128K ROM. According to https://worldofspectrum.net/permits/ we have the following: "Amstrad, the current owners of the Sinclair ZX Spectrum, allow free distribution of the ZX Spectrum ROMs (see the message from Amstrad as posted in comp.sys.sinclair for the details), and endorsed WoS at its 7.5 year anniversary.
Therefore, emulation of the machine is not illegal (as opposed to nearly all other computers that are emulated these days).
This gives us an advantage in that it actually makes sense for publishers to allow distribution of their software." - Games:
- Krackout and Ramparts are purchased
Full repository (except two purchased games) is here https://alxlabs.ca/speccy.php
08-MAR-2024
Having ZX spectrum implemented on FPGA boards is a cool project while I've been looking for a cheaper solution as it currently works on ~$100 boards. I don't need a high gate count, the entire design just takes ~4000 ones while I need a static RAM onboard or if SDRAM is populated then there should be hardware support for it on FPGA, not another "soft" module as those are slow. While I still have not decided if I want to make my own PCB for that.. - the full article is available on https://alxlabs.ca/?ZX-Spectrum_128K_on_FPGA
24-FEB-2024
Project "Myweather" was created several years ago, but it still runs collecting the data for current weather with intervals of 10 minutes. See actual weather here
Do you need the data? Contact me on a Facebook
24-FEB-2024
While ago I've purchased an Artix-7 FPGA board, it was really cheap (~$39USD) and by looking at the specs - Artix-7 is a good choice for another implementation of ZX Spectrum. But.. it takes too long to synthesize anything in Vivado (I have version v2023.2 (64-bit), way longer than for any other FPGA I tried, it feels like I'm trying to run a modern application on a 10 yrs old laptop, this was not the case for the Xilinx nor Altera. Does anyone know why?
19-FEB-2024
FPGA ZX-Spectrum 128K with AY8910 (or..8912) is fully working now!
I've been thinking for a while about why only some small quantity of ZX 128 games/demos on my version of AY8912 produces some weird sounds on the FPGA board but it works perfectly fine in SW simulations while the vast majority works well on both... It was extremely hard to debug as every time the game had to be loaded, then some tests done, then the game reloaded, etc... Until I found a straightforward way to write a Basic program, just a few lines, to play a simple tone that plays just some noise on my Speccy and found that I was processing BDIR and BC1 signals incorrectly, the proper way is shown on the pictures below. Now everything works and plays perfectly 
I also put everything in one place for easier download should anyone want it. Bonus: one nice thing I developed from scratch was an Arduino (I use Seeduino as it has the smallest form factor among other Arduino boards) loader for downloading the sw from SD card into Speccy. Note that I developed my own format named "fst" for fast downloads (x8 speed) so all files that have the extension "fst" are treated this way. If you want to convert TZX/etc files then those should be converted into plain .wav (I use winTZX converter) and then processed via audio converter which is written by me as well, sources are available along with other things mentioned above at the link below.
Full version: https://alxlabs.ca/?ZX-Spectrum_128K_on_FPGA
24-JUL-2023
Memories just came to me after a short searching for our cat (again) regarding TractiveGPS for cats... See the picture (picture is done using mobile data only to get tractive position and then mobile data turned off (airplane mode) while keeping GPS on - it did not have any effect on the phone's position):
Tractive device is located side by side with the phone, both devices are located on the 2nd floor of our house, distance between them is just few cm, phone is in the airplane mode to avoid any additional methods of positioning being used. While Tractive app shows position of the device 18m (!!!) away from real position despite that they are side by side. Phone is showing location waaaay more precisely even it is in the airplane mode. I remember a little issue - our cat has lost it's tracker, came back home without it. I went on the street trying to locate the device, found an approximate location, tried to use Bluetooth to find it more precisely, but Bluetooth dos not give you the direction, all you have is information how close you are to the device so I was not able to find it. Turned on the beeper and the light - still did not hear nor saw it.. Very disappointed came back home, then went out in the night to locate the device by enabling the LED - hurray, I found it. To find out the real cat in the real situation with this precision - good luck with that, we tried couple of times and have not succeed. My own conclusion - Tractive device is very well built, have no single problem with that, battery is good enough. While GPS on it has a lower resolution than a phone but this is not a main problem - you can find your cat only if cat wants it and sits still while you will be playing with sound and light on this device.
Update: tractive support is very good, I've been contacted by Tractive however it was only to find out that my device performs exactly as it supposed to.
27-FEB-2023
Attempts to re-create128K ZX on Gowin FPGA have failed due to lack of support from Gowin on the ports IO issue. On the positive side I have completed ZX 128K + AY-8912 on the Altera while Altera is a bit expensive. If anyone is interested in that:
https://alxlabs.ca/ZX_Spectrum/v2_altera_final.zip
01-JAN-2023
...Just did it :)
doing ZX spectrum on the FPGA board for under 15$ ... At this moment the whole thing is just a prototype to prove that it is doable on the extremely cheap gowin fpga. Had to solve a lot of problems related to compiling existing Z80 though but so far so good. Next step is to do a full blown version now
Update: submitted to JLCPCB for fabrication
01-SEP-2022
I made it! ZX Spectrum clone on FPGA. Tried both CPUs, T80 and A-Z80... While both CPUs are great emulation of Z80 but Goran's A-Z80 is the best, size is the smallest while accuracy is above everything. It is implemented on kind of expensive Altera Alinx board however I have a plan to make it on a small and cheap Gowin FPGA, let's see if I will succed. Big thanks to Baltazar Studios and personally to Goran Devic
Click here to see the details :)
Here is the video of Ramparts:
11-MAR-2016
Auch... First of all, I found that I'm missing a couple of DDLs in the release package, very sorry for that. And second - the new release is ready and can be downloaded from here.
PS: email your comments to
07-MAR-2016
Wow.. collision detection is turning to be much more complicated than I originally thought. I planned to quickly develop it and put another version for download but looks like it will be several more days. ..Precision vs FPS.. Yup.
17-FEB-2016
Finally it is 2016... all New year/Xmas parties are done now... I decided to refresh my memory in C++ and probably study something new.. and I remembered that long-ago time I started learning OpenGL so I decided to write a game this time, but not sure what will be the scenario. Meanwhile I just did a little man motion program, it can be downloaded by clicking here.
PS: email your comments to (sorry, had to do an image to minimize the spam)
09-DEC-2015
A lot of business trips, mainly to Seoul.. there was no time to update the blog. But..Finally... It is a Xmas season, New Year and a vacation afterward, which means tons of new pictures :) .. well.. soon
15-OCT-2015
I was wrong and underestimated spammers... Had to modify my code again adding fully custom part...
14-OCT-2015
Gee… My other website (PhpBB) got flooded with spam yesterday... I had to severely increase the level of protection, remove spambots (which sometimes can be confused with new users who are registered but did not made any posts)... By tracing those attacks I came to an interesting website - http://www.botmasterlabs.net/xrumer/ .. damn .. I was thinking for a bit and made some changes to anti-spam text-captcha - for example "three plus 7 = (made middle letter capital, i.e. sIx)" .. seems OK at the moment.
09-OCT-2015
OK, Everything is in place as of now, the site has been migrated into a long life form :) - pictures, stories - everything has its own place now... And Happy Thanksgiven everyone!
..By the way.. Wondering how frequently Google will index this content. Let's see
07-OCT-2015
Today I decided that footer boxes are not required at the moment, but what I'm missing most - is a gallery. Need to find out a suitable one...
Update: found. I think I will use TinyWebGallery
06-OCT-2015
I was thinking that CMSimple is a perfect product to do a personal website. Very important thing - it does not require database so one headache less. Previous alxlabs.ca design was self-written in 2001 which is
a. Too long time ago
b. Design itself is not modern
c. I did not have enough time to do everything nicely, so I was searching for some open source or free CMS and found given one...tadadada.. CMSimple it is!
- Games:
- Krackout and Ramparts are purchased
Full repository (except two purchased games) is here https://alxlabs.ca/speccy.php
