Introduction I recently ordered a Powkiddy X55 handheld retro gaming device. It cost under £50 including delivery to the UK, direct from the Powkiddy website and took around a week to arrive. It’s a really great device, here are the specs: Screen: 5.5-inch IPS 1280×720 (16:9) CPU: Rockchip RK3566, Quad-core ARM Cortex-A55, CPU Clock Speed: 1.8GHZ GPU: ARM Mali-G52 RAM: LPDDR4X, 2GB Storage: Two TF/microSD card slots Battery: 4,000 mAh Li-battery; typical usage around 3-4 hours depending on the load. Connectivity & ports: WiFi, Bluetooth, 2× USB-C (charging/OTG), mini-HDMI output (for TV connection), 3.5mm audio jack Controls: Dual analog sticks, D-pad, face buttons, shoulder + trigger buttons (L1/L2/R1/R2 stacked) Stereo speakers Setup Retro Game Corps have done an excellent guide to setting up the X55, but here are my quick notes: ...

There are various ways to writing computer programs for the Spectrum Next ranging from developing on the machine itself, to writing the code on a separate PC and copying it across when done. The three main languages that can be used, in order of difficulty are: BASIC C Z80 Machine COde Here are some notes on these options. Programming in BASIC There are a few options for writing BASIC for your Spectrum Next. ...

Ares is a great multi-system emulator supporting a wide range of retro machines. It’s not obvious what file formats are supported though, so here’s a list: atari-2600 a26, bin bs-memory bs colecovision cv, col famicom-disk-system fds game-boy-advance gba game-boy-color gb, nbc game-boy gb game-gear gg master-system ms, sms mega-32x 32x mega-cd cue, chd mega-drive md, smd, gen, bin msx msx, wav msx2 msx2, wav myvision miv neo-geo-pocket-color ngpc, ngc neo-geo-pocket nap neo-geo ng nintendo-64 n64, v64, z64 nintendo-64dd n64dd, ndd pc-engine-cd cue, chd pc-engine pce playstation cue, chd, exe pocket-challenge-v2 pcv2, pc2 saturn cue, chd sc-3000 sc3000, sc sg-1000 sg1000, sg sufami-turbo st super-famicom sfc, smc, swc, fig supergrafx sgx wonderswan-color wsc wonderswan ws zx-spectrum wav, tzx, tap

Here is a list of the file formats that I use within emulators, I prefer compressed files when possible as it saves on disk space. Generation System Best File Format Home Computer ZX Spectrum 7z Commodore 64 7z Amstrad CPC 7z Amiga 500 LHA Portable Game Boy 7z Game Boy Advance 7z Nintendo DS 7z Sony PSP CSO but don’t always work 3rd Atari 7800 7z Sega Master System 7z NES 7z 4th Sega Megadrive 7z SNES 7z 5th Sega Saturn CHD Playstation CHD (or PBP) Nintendo 64 None are reliable 6th Sega Dreamcast CHD Nintendo GameCube RVZ Sony PS2 CHD Microsoft Xbox SquashFS 7th Nintendo Wii RVZ 7z 7z is a file format created via the “7zip” utility. It’s got good compression levels and most of the emulators for the older systems can read this format. Normal “zip” files can usually be used too. ...

I had issues with my Dell Optiplex 3050 micro PC not booting via UEFI into Batocera Linux. When trying to boot, I was stuck on a black screen with the message “Booting Batocera.linux” but the system wouldn’t continue to boot. If I switched the Dell Optiplex BIOS to use “Legacy” boot then it worked, but then the PC wouldn’t recognise other OS installations if I swapped out Batocera, and I didn’t want to have to keep fiddling with the BIOS settings turning Legacy mode on and off. ...

Here’s a quick post on how I got some Z80 assembly code onto my Z80 SC114 SBC from Linux. This is using the fantastic Small Computer Monitor software that comes pre-installed. First, install the necessary packages. Be sure to use z80asm and z80dasm from the repositories rather than the one that comes with z88dk if you have that installed. From Linux: - sudo apt install z80asm z80dasm srecord Or from MacOS: - brew install z80asm z80dasm srecord ...

Back in the 1980’s, if you were writing code for the ZX Spectrum, you could use the built-in basic interpreter or Z80 machine code for better performance. Now there are other options, including higher level languages such as C. z88dk is a great project that allows you to compile C for the ZX Spectrum and ZX Spectrum Next. It also includes some libraries to make doing common things easier. There’s a great getting started guide here and I’ve included my quick notes taken from that guide below. ...

The Z88DK project provides C compilers and libraries for over 100 Z80 machines, including the RC2014, ZX Spectrum and ZX Spectrum Next. Here are some quick notes showing how I got Z88DK working on my Raspberry Pi 4. Just installing z88dk via apt resulted in an old version, so I opted to install from source instead. Dependencies First I installed some dependencies: - sudo apt install libxml2-dev sudo apt install bison sudo apt install flex sudo apt install libboost-all-dev Code Download Then I downloaded and uncompressed it: - ...

Here are a few emulators that I’ve found that are easy to install on a standard installation of Raspberry Pi OS (formerly known as Raspbian). To install them, use the following command: - sudo apt install <package-name> Without further ado, here’s the list: - fuse-emulator-gtk - ZX Spectrum osmose-emulator - Sega Master System / Game Gear stella - Atari 2600 openmsx - MSX nestopia - NES desmume - Nintendo DS dosbox - DOS yabause - Sega Saturn mame - MAME pcsxr - Playstation

If you’re interested in the architecture of computers and how CPU’s, RAM etc. are built from logic gates, then here is my selection of some good books to read. Not only do they explain the fundamental hardware needed, they go on to explain assembly language, operating systems etc. But How Do It Know? by J Clark Scott This is a great book that explains how computers are built, from NAND gates up. Each chapter goes through how a particular component is built, and these components are connected together in further chapters to create a full computer. No technical background is required, and it really does explain things well. Some of the topics aren’t covered in too much depth but the range is excellent. ...