emulator

177 Articles

ESP32 Powers Single-PCB ZX Spectrum Emulator

June 16, 2024 by 21 Comments

When word first got out that the Chinese board houses were experimenting with full color silkscreens, many in our community thought it would be a boon for PCB art. Others believed it would be akin to cheating by removing the inherent limitations of the medium. That’s not a debate that will be solved today, but here we have an example of a project that’s not only making practical application of the technology, but one that arguably couldn’t exist in its current form without it: a single-PCB ZX Spectrum emulator developed by [atomic14].

There basics here are, well, they’re pretty basic. You’ve got an ESP32-S3, a TFT display, a micro SD slot, and the handful of passives necessary to tie them all together. What makes this project stand out is the keyboard, which has been integrated directly into the PCB thanks to the fourteen pins on the ESP32-S3 that can be used as touch sensor input channels. There are issues with detecting simultaneous keypresses, but overall it seems to work pretty well.

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Making Intel Mad, Retrocomputing Edition

June 9, 2024 by 20 Comments

Intel has had a deathgrip on the PC world since the standardization around the software and hardware available on IBM boxes in the 90s. And if you think you’re free of them because you have an AMD chip, that’s just Intel’s instruction set with a different badge on the silicon. At least AMD licenses it, though — in the 80s there was another game in town that didn’t exactly ask for permission before implementing, and improving upon, the Intel chips available at the time.

The NEC V20 CPU was a chip that was a drop-in replacement for the Intel 8088 and made some performance improvements to it as well. Even though the 186 and 286 were available at the time of its release, this was an era before planned obsolescence as a business model was king so there were plenty of 8088 systems still working and relevant that could take advantage of this upgrade. In fact, the V20 was able to implement some of the improved instructions from these more modern chips. And this wasn’t an expensive upgrade either, with kits starting around $16 at the time which is about $50 today, adjusting for inflation.

This deep dive into the V20 isn’t limited to a history lesson and technological discussion, though. There’s also a project based on Arduino which makes use of the 8088 with some upgrades to support the NEC V20 and a test suite for a V20 emulator as well.

If you had an original IBM with one of these chips, though, things weren’t all smooth sailing for this straightforward upgrade at the time. A years-long legal battle ensued over the contents of the V20 microcode and whether or not it constituted copyright infringement. Intel was able to drag the process out long enough that by the time the lawsuit settled, the chips were relatively obsolete, leaving the NEC V20 to sit firmly in retrocomputing (and legal) history.

Using Kick Assembler And VS Code To Write C64 Assembler

June 6, 2024 by 3 Comments

YouTuber [My Developer Thoughts], a self-confessed middle-aged Software Developer, clearly has a real soft spot for the 6502-based 8-bit era machines such as the Commodore 64 and the VIC-20, for which he has created several video tutorials while travelling through retro-computing. This latest instalment concerns bringing up the toolchain for using the Kick Assembler with VS Code to target the C64, initially via the VICE emulator.

The video offers a comprehensive tutorial on setting up the toolchain on Windows from scratch with minimal knowledge. While some may consider this level of guidance unnecessary, it is extremely helpful for those who wish to get started with a few examples quickly and don’t have the time to go through multiple manuals and Wikis. In that regard, the video does an excellent job.

VS Code is a great tool with a large user base, so it’s not surprising that there’s a plugin for using the Kick Assembler directly from the IDE. You can also easily launch the application onto the emulator with just a push of a button, allowing you to focus on learning and working on your application. Once it runs under emulation, there’s a learning curve for running it on native hardware, but there are plenty of tutorials available for that. While you could code directly on the C64 itself, it’s much more pleasant to use modern tools, revision control, and all the conveniences and not have to endure the challenges.

Once you’ve mastered assembly, it may be time to move on to C or even C++. The Oscar64 compiler is a good choice for that. Next, you may want to show off your new skills on the retro demo scene. Here’s a neat C64 demo with a twist. There is no C64.

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Emulate A KIM-1 With A Commodore 64

May 12, 2024 by 1 Comment

When you think about virtualization, you usually think about making some CPU pretend to be another CPU. However, there are sometimes advantages to making a computer pretend to be the same computer.

That’s the case with [oldvcr]’s KIMplement, which emulates a KIM-1 with a 6502 using a Commodore 64, which also uses a 6502.The reason this makes sense is that you have total control over an emulated CPU. If a program, for example, writes to a critical memory location or tries to take over the screen or keyboard, you can easily make the emulator do something more appropriate. Things like breakpoints and single stepping also become trivial.

The virtual machine at the heart of it is 6o6 (6502 on 6502), and it seems to perform well. By virtualizing, you can easily protect the system from programs that try to, for example, take over an interrupt vector. This is similar to how x86 protected mode can run old real-mode code in a virtual environment and intervene for certain instructions. The emulation is good enough that the emulator can run the emulator, which then runs the emulator to actually run the real target. That’s wasteful, of course, but it does speak to the completeness of the pretend CPU.

If you want a KIM-1 (and an 1802 Elf) but only have an Arduino, you can emulate a different way. At least an emulated KIM-1 doesn’t develop bad memory chips.

Pi Pico Gets A ZX Spectrum Emulator

April 27, 2024 by 9 Comments

The Pi Pico is a capable microcontroller that can do all kinds of fun and/or useful things. In the former vein, [antirez] has ported a ZX Spectrum emulator to the Pi Pico.

ZX2040, as it is known, is a port of [Andre Weissflog’s] existing ZX spectrum emulator. It’s designed for use on the compact embedded Pi Pico platform, using ST77xx TFT displays. To that end, it has a UI optimized for small, low resolution screens and minimal buttons. After all, very few Pi Picos come with a full QWERTY keyboard attached.

Certain hacks are necessary to make it all work; the chip is overclocked to get things humming fast enough. The emulator also runs upscaling or downscaling in realtime as needed. This allows the emulator to run with a variety of displays, almost none of which are a direct match for the ZX Spectrum’s original resolution of 256×192 pixels.

Code is on Github for the curious, including a great run down from [antirez] on everything that makes it tick. If you want to play ZX Spectrum games on a keychain, you’d do well to start here. There are other projects to emulate it on the Pico, too! Video after the break.

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The BBC Micro, Lovingly Simulated In VR

April 14, 2024 by 5 Comments

The BBC Micro was many peoples’ first exposure to home computing, and thanks to [Dominic Pajak], you can fire up this beloved hardware in WebXR. Is it an emulator? Yes, but it’s also much more than that.

The machine, the CRT, the keycaps, and even the sounds of the original keypresses are all brought to life as accurately as possible. The result is not just an emulator. It’s a lovingly-made BBC Micro simulator you can use with a VR headset. Or just use your browser and type on your real keyboard if you like.

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Retro Hackintosh Made From Retro Parts

March 25, 2024 by 20 Comments

Apple as a company, has staked most of its future around being a “walled garden” where it controls everything from the hardware up through the user experience. In some ways this is good for users; the hardware is generally high quality and vetted by the company creating the software, making for a very uniform experience. This won’t stop some people from trying to get Apple’s operating systems and other software running on unapproved hardware though. These “Hackintosh” computers were much more common in the Intel era but this replica goes even further back to the Macintosh era.

Originally [Kevin] had ordered an authentic Macintosh with the intent of getting it working again, but a broken floppy disk drive and lack of replacement parts turned this project into a different beast. He used the Mac instead as a model for a new 3D-printed case, spending a ton of time sanding, filling, and finishing it to get it to look nearly indistinguishable from the original. The hardware going in this replica is an old Linux-based thin client machine running the Mini vMac operating system, with a modified floppy drive the computer uses to boot. A hidden SD card slot helps interface with modern computers. The display is a modern LCD, though a sheet of acrylic glued to the front panel replicates a bit of the CRT curve.

Click through to read on!

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