Writing an emulator for a CPU or entire system is a great programming project. Some of the old 8-bit CPU’s can be emulated fairly easily and running them at a decent speed isn’t a problem for modern PC’s. In addition to the CPU, code will be needed to emulate any graphics and sound hardware too. Here are some notes on where to start. CHIP-8 Chip 8 is usually the first place to start – its actually an interpreted programming language…
The Zilog Z80 CPU is still being produced – not bad for a CPU introduced in 1976. When buying a Z80 CPU, it helps to understand the format of the part numbers used. For example, “Z84C0008PEG” The Z80 most commonly used for hobby projects is the “CMOS” version. This CPU starts with the six characters “Z84C00” (the “C” means “CMOS”). The 7th and 8th characters determine the speed in Mhz. The 9th determines the package type (in this case, “P”…
Here are some links to some single-board computer kits using the Z80 CPU that I have found. The RC2014 is a SBC kit built with a backplane so that numerous modules are available to expand it. Firstly, the RC2014 Classic II kit (around £76) contains 5 modules (CPU, ROM, RAM, Serial I/O and Clock/Reset) all connected separately to a backplate. The RC2014 Mini kit (around £64) combines all of these modules onto the same board to make things easier to…
There are various kits available to allow you to assemble a computer that’s compatible with various systems from the 80’s. Here are a few that I have found. The Minstrel 2 by Tynemouth Software is a self-assembly Sinclair ZX80 compatible computer kit that comes with its own keyboard. The Minstrel 3 (also by Tynemouth Software is a similar self-assembly kit, but based on the Sinclair ZX81. Another kit from Tynemouth Software is the Minstrel 4th which is a Jupiter Ace…
Here are a few interesting projects that I’ve found to build a basic Z80 computer on a breadboard. Bread80 is a really well explained blog describing the author’s project in creating a Z80 computer. This is the one that I am following along with! L Break into Program also has a nice write-up of a breadboard-based Z80 computer – here is part one. The website has loads more useful information on retro computers and programming, including ZX Spectrum resources. Finally,…
I’ve just ordered a ZX Spectrum Next (issue 2) on Kickstarter. This is a newly-designed machine that is backwards compatible to the original ZX Spectrum 48, 128, +2 and +3 models. It has updated hardware, with 1Mb RAM, and a Z80 processor able to run in 3.5MHz, 7MHz, 14MHz and 28MHz turbo modes. The hardware logic is built using a Field-programmable gate array (FPGA) which means the CPU, ULA etc. can be re-created within this one chip. Storage is via…
8bitworkshop is a fantastic website that lets you write and test code for a wide range of retro 8-bit computer systems within your browser. It has a great IDE with memory browser, disassembly etc. The ZX Spectrum, Commodore 64, MSX, Atari 2600, NES and Sega Master System are among the supported systems. The functionality is amazing, a lot of hard work has obviously gone into this project. The owner of the website has also released a range of books. These…
For reference purposes, here is the pinout for the Zilog Z80 CPU. Yellow A0 to A15 = Address bus Blue D0 to D7 = Data bus Pink CLK = Clock signal Red & Black VCC = +5v GND = Ground Purple RFSH = outputs a signal to allow for memory to be refreshed M1 = Z80 is fetching next instruction from memory RESET = used to reset the Z80 BUSRQ = Bus Request (used by external devices to request control WAIT = makes…
This is a list of home computers and games consoles that use theMOS Technology 6502 chip or a variant. The basic design of these CPU’s are 8-bit and the basic 6502 instruction set works in the same way on all these systems. I will add more information about these systems when time allows. Apple I – 1976 [6502] Commodore PET – 1977 [6502] Atari VCS (later known as 2600) – 1977 [6507] Atari 400/800 – 1979 [6502] Commodore VIC-20 –…
Here’s a quick list of the most popular home computers and games consoles that used the Zilog Z80 chip (or a variant in some cases such as the Game Boy). I will add more information to the website on each of these platforms and link to them from here over time. Sega VIC Dual (1977) ColecoVision (1982) ZX Spectrum (1982 onwards) Camputers Lynx (1983) MSX (1983) Amstrad CPC (1984 onwards) MSX2 (1985) Elan Enterprise (1985) Sega Master System (1985) Nintendo…