Just the signal, not the noise

Hello 8bit'ers,

two more weeks, and incredibly enough the world has not blown up. 😮‍💨 And since that’s the case, it had to happen … it’s Friday again. Unbelievable. But even more unbelievable is the number of topics, we just didn't want to leave out of this issue, so we reduce the bla-bla a bit to compensate.

We start with the release of Eye of the Beholder for the C64, there is some interesting hardware, software and a (at least for some) new, super interesting video series.

Let's get started with Issue #66. Enjoy!



Imagesource: https://www.wtsretro.dk/

In 1986, Berkeley Softworks - later known as GeoWorks - released GEOS, the graphical operating system known to pretty much everyone, who owned a C64/128. 

The history of GEOS, the Graphic Environment Operating System, is wild. At its best, the OS for the Commodore machines was the third most popular operating system behind MS-DOS and MacOS.

Interestingly (but also absolutely logically) there was a port for the Commodore +4 and in 1988 a port for the Apple ][ series, attempting to outrun Apples own OS. There are no other ports.

Ah, wait. Maciej Witkowiak aka @ytmtym proved us wrong this week. 36 years after the initial release, here we go:


The history of this port reads interesting. Already some years ago Michael Steil had prepared sources from a previous reverse engineering attempt for the CA65 Macro Assembler, now Maciej has made the necessary adjustments, to get the system running on his Atari 65XE.

Exciting thing this. If you live on the ATARI side of the river. 🟥 

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Foldable Gameboy

Pocket SP - foldable Gameboy
Imagesource: https://decontextualize.com/

Gameboy modding is a thing. And oh boy ... that's a mod!

Nintendo isn't exactly known for simply leaving possible hardware innovations lying around on the street. As part of a diabolical plan to optimize its profits, the company mostly did exactly the opposite. And so a foldable Gameboy is already available with the Game Boy Advance SP.

But why buy something, when you can build it yourself? 🤓

Allison Parrish known as @aparrish hopped right into this adventure, hacking her Game Boy Pocket in half. Literally. 🪓

The result is impressive, and the story behind it reads at least as exciting, as this project is cool.

Copy it? The bill of materials is there. The necessary skills you have to bring yourself.

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6560 VIC Replacement

6560 VIC Replacement
Imagesource: https://imapenguin.com/

One of those news that almost got lost in the noise of our beloved, international, IP based ether this week came from an individual named Jon running the YouTube channel Vicenary.

Quite nonchalantly, the good man presented a VIC chip replacement based on an FPGA! 🫢

Apart from the fact that we already have a replacement for the graphics generator of the C64/128 with VIC-II Kawari, now also the VIC-20 gets the benefit of fresh hardware, and in future restoration projects you may soon be able, to get along without possibly unreliable chips from the 70s or 80s.

The demo video is short, but contains everything you need to know. Especially that the project is currently still in the test phase, and we have to wait a bit. ⌛️

But that's what people like to wait for. 

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Tiny CP/M

Tiny CP/M
Imagesource: https://www.tiendatec.es/

CP/M is alive. Very much alive. And the 48 years of life loom up only, if you take a closer look. A whole series of homebrew-retro-solder-it-yourself-diy-systems™ adorn themselves with CP/M compatibility ... and for a reason or two. There is a small but nice mini-universe of software at your disposal.

Kian Ryan - @kianryan on Twitter is usually running an RC2014 with CP/M, but was looking for an even more portable solution.

And so he piggybacked an Adafruit Micro SD SPI Breakout to a Pimorony Tiny 2040 and got RunCPM-Pi-Pico running on this little, neat thing.

Exactly your topic? Then have fun with his story.

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Retro Virtual Machine

Imagesource: https://www.retrovirtualmachine.org/

In Issue #57 we touched on the Retro Virtual Machine by Juan Carlos González Amestoy - @retrovm - unfortunately only tangentially.

What a shame, because the software is of such high quality, that we have to dedicate at least one whole article to it. So here we go:

RVM is a classic emulator that pretends to be a ZX Spectrum or an Amstrad CPC. That alone is almost a unique selling point, but the project comes with a whole bunch of lovingly designed goodies. Besides a virtual cassette player, and low level disk emulation you get gamepad support, SD card functionality, a perfect monitor emulation including GPU based post processing functionalities for scanlines, blur and pixel mask.

High quality audio goes without saying, and if you want to use the thing for more than just playing games, you'll get your money's worth with the integrated assembler and debugger.

Ingenious project, you’ll have to give it a try. 

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X86BOX - IMB PC Emulator
Imagesource: https://86box.net/

Feeling a little adventurous? Switch to the side of evil for once? Then how about a wonderfully refreshing emulation of an 8086 system, or a Pentium I based machine?

At least with the help of MS-DOS and the associated fiddling with autoexec.bat and config.sys, retro-frustration ... ehhmm - fun comes up very quickly.

And if you don't want to mess up your garage with a machine having an IBM logo printed on it, you might want to consider X86Box

The project by Miran Grča, known on Twitter as @86BoxEmulator is a competent emulator, that has so far passed us by. With a focus on accuracy additional hardware is simulated besides the CPU. Video adapters, sound cards, network adapters, hard disk controllers, and SCSI adapters but also MIDI output and an emulated Roland synthesizer make this piece of software interesting.

It runs on Windows, Linux and MacOS and brings MS-DOS, older versions of Windows, OS/2, NextStep or BeOS onto your monitor. Hhhhmmm BeOS ... 🤤

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Curated SID Collection

Curated SID Collection
Imagesource: https://unsplash.com/

You need a short intermezzo? A little break? You love music? SID? Then check out the Curated SID Collection by Jostein Trondal

The number of SIDs available on Jo’s site is ... overwhelming. Seems to be complete, but how do you even measure that? In the end there is a whole mountain of sound files waiting for the excited SID connoisseur.

A JS based player is included on the site, so that you can play the pieces without further detours. Unfortunately there seems to be a problem with Chrome, but all other browsers we tested, ran the player without any problems. (Chrome, the new IE11? 🤔)

In any case, a great collection, in which you can find quite a few unexpected gems as well as many memories of your own past.

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8080 Extension in Apple’s CPUs

8080 Extension in Apple's CPUs
Imagesource: https://apple.com/

Imagine that Apple - in addition to the ARM IP cores - planted supplementary circuits in their M1 and M2 CPUs, just to execute certain instructions of 8080 CPUs directly in hardware instead of software.

This sounds rather pointless at first, considering how many instructions such a thing can execute per second. The software emulation of a few, quite old instructions doesn't really matter, or does it?

Blake Patterson alas @blakespot presents an interesting piece of investigation on the topic. Because actually the real situation is somewhat different. Apple plays on the fact of in-house CPU production in a rather ingenious way, and - utilizing the care described above - makes sure, that Rosetta2 can emulate x86 code as incredibly fast as it actually does. 💨

The story behind it is interesting, entertaining, and a nice read for your train ride home.

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MS-DOS Inside Look

MS-DOS Design Decisions
Imagesource: Microsoft via Wikimedia Commons

And we'll briefly stay in the corner of systems with a few more than just 8 bits, because it's already fluffy and warm here.

For many who have experienced the 8-bit era in person, but then at some point had to (or even wanted to) switch to a 32-bit bolide, have certainly spent a lot of time in front of a black screen with white letters on it. We talk about MS-DOS.

But what many don't know, is that a good part of MS-DOS actually comes from 86-DOS by Tim Paterson, which at that time mainly aimed at CP/M compatibility.

A writeup by Paterson surfaced on HN this week, and for those who feel the historical interest deep down in their heart, The design decisions behind the popular operating system will provide suitably meaningful entertainment for at least a few minutes.

Nice reading material.

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2FA with the C64

2FA with C64
Imagesource: http://oldvcr.blogspot.com/

The sentence that definitely sticks with this project is the following. Quote: Some of you are already asking if this idea is totally nuts or just mostly. 🤪

What is it about? It’s about using the C64 as a 2 factor authentication system.

To be honest, the idea is not that far-fetched. For one thing, the necessary algorithms are not so complex, that they couldn't be run by a 6502 in real time. For another, it is rather unlikely, that a thief will tuck the breadbox under his arm before running off - unlike a modern smartphone.

However, how to generate 2FA tokens anywhere other than your own 4 garage walls, is one of the questions whose answers ClassicHasClass - possibly @mpc7500v2 - leaves open.

But one thing is for sure, Saturday afternoon is saved. It's a POC that you just have to try. If you feel like it, you can find the whole experiment with all the trimmings here.

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Imagesource: https://github.com/ZXDunny/

Another Platinum project that completely passed us by, is SpecBAS by Paul Dunn - @ZXDunny on Twitter. 

But before you actually click either link, check out this demo video first.

That so little code can create so much screen fireworks, is always amazing. In this case however, it actually seemed rather unbelievable to us. The fact is, that the code of the demo called bubble_universe actually works. But it is so performant and colorful only thanks to Paul's modern BASIC environment.

This in turn is really ingenious. Because it not only makes arbitrary code run with much more CPU cycles per second, it also increases the number of available colors as well as the maximum resolution and aspect ratio.

If you liked BASIC on Sinclair's machines, you'll love SpecBAS. Unfortunately only for Windows and a bit fiddly to install, but there are emulators for that.

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WozMon on the 2600

Woz-Mon on ATARI 2600
Imagesource: https://hackaday.io/

Before we get into the details of the following story, let's just mention a few keywords: ATARI 2600, DIY serial, bit banging, Woz-Mon.

Does this make any sense to you?

I think the title already made it clear. What Johannes le Roux - also known as @dadecoza - accomplishes here is just pure fun.

Take a standard ATARI 2600, build your own serial port interface and use some Python, patience and perseverance to bitbang the slightly modified Woz-Mon binary into the console's RAM. 

A nice little experiment that Johannes describes in great detail here.

Nice to read.

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Sol-20 Intelligent Terminal

Sol-20 Intelligent Terminal
Imagesource: https://youtu.be/pgkhBOc5V-c

If anyone isn't going to shy away from an extra mile, two or a hundred for a vintage rebuild project, it's Brad aka @TechTimeTravel. We've had content from Brad in past newsletters, but his latest project is once again one of those gems, whose brilliance can seriously sweeten up a nice evening with your beverage of choice, in front of your YouTube transmitter of choice, on your seating of choice.

Brad rebuilds an SOL-20 terminal computer from Processor Technology, and documents his entire journey, which involves quite a few ups and downs.

32 minutes and exactly 25 seconds, containing rather less new information, but definitely fun to watch if you like retro rebuilds.

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Superscalar CPU Design

Superscalar CPU Design
Imagesource: Fabian Schuiki

No idea whether this is still understandable today, but as a child I loved the sweets from Quality Street. Unfortunately, the bitter thing was, that my grandma could only bring them exactly once a year, so the beloved sweets could definitely be called rare in our home. And what do you do, when you're a kid, and you've got a NERD gene or two? You save the best pieces for last. (In my case, it was the orange ones.) 🍬

And since said gene is still active today, IMO the best post of this current issue also comes at the end. Big thanks to our reader Robert N. for bringing the following series to our attention.

Fabian Schuiki - @fabianschuiki on Twitter - may not have a name like Ben Eater, but he follows in his footsteps all the more energetically. But the shoes he puts on, are 2 sizes bigger. 

Fabian builds a CPU. In contrast to Ben's sub-scalar SAP 8-bit design, Fabian chooses the other side of the complexity scale and builds a superscalar architecture with out-of-order execution … on breadboards! The claim - namely the comprehensibility of the topic even for non-professionals - is the same, though.

An ingenious video series, from which we can hopefully expect a lot more in the future.

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It will be interesting to see, what the next 2 weeks will bring. But that's it again for the current Issue #66.

As always, we hope that one or the other topic has actually generated resonance.

If you feel a little ❤️ for our publication, feel free to help us out and spread the word. This will definitely boost your Karma.

If you have a topic for an upcoming issue, feel free to reply to this email. We read everything, and always reply.

Issue #67 is coming in 2 weeks from today. Until then - build something, and speak about it.


Jan & Bastian

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