Electronics Projects Index

After transitioning to WordPress, I started writing up my newer projects as ‘blog posts’ rather than ‘pages’. Please find below a list of links to every electronics project related blog post:

• Olivetti M20 Upgrades, Tips, Tricks, and New Boards

The Olivetti M20 is a vintage computer based on the Z8000 Z-8000 CPU. I show how to upgrade the memory, add a compactflash adapter, add a USB adapter, use the 8086 APB, program in forth, design a speech systhesizer, and play some zork.



• The Mini-08 8008 Single Board Computer

The mini-08 is a single board computer based on the Intel 8008 CPU, and 8-bit CPU from the early 1970s that launched the commercial 8-bit computer revolution.



• 8008 CPU Board for the Heathkit H8 Computer.

8008 CPU Board for the Heathkit H8 Computer. The H8 typically comes with an 8080 CPU board. I decided to go a few years earlier and build an 8008 CPU Board.



• FANUC PPR (Portable Punch Reader): Paper Tape on RC2014 and Heathkit H8

FANUC PPR Paper Tape Punch and Reader, repaired and modified to use with RC2014 and Heathkit H8 vintage comptuers.



• Single Board Bubble Basic Computer, and an RC2014 Bubble Board

Designing a single board computer that supports Bubble Memory, as well as an RC2014 Bubble Memory board.



• Controlling an AKI Teletypesetter Keyboard with a Raspberry Pi

Controlling an AKI Teletypesetter Paper Tape Punch from a Raspberry Pi microcontroller. Vintage punched paper tape project.



• Heathkit H8 Bubble Memory Board

Bubble Memory using the 7110AZ one megabit bubble memory device for the Heathkit H8 Computer, including the ability to read and write bubble memory as disks, and boot from bubble memory devices.



• 16 Megabytes of RAM in a Heathkit H8 Vintage Computer

Designing an 8 megabyte RAM board for the Heathkit H8 Vintage Computer, using memory paging to map the 8MB memory space into 64KB of CPU address space. Uses AS6C4008 RAM chips or 39SF040 flash chips. Includes Ramdisk driver for Heathkit HDOS.



• Designing a DRAM board for the Heathkit H8 Computer using the Intel D8203 DRAM controller

I develop my first DRAM project, a DRAM memory board for the Heathkit H8 computer, using the Intel D8203 DRAM controller IC.



• Blinkenlights for the Heathkit H8 Computer

Blinkenlights board for the Heathkit H8 computer, also a convenient place to connect logic analyzer probes to the H8.



• An 8085 CPU Board for the Heathkit H8 Computer

An 8085 CPU Board for the Heathkit H8 Computer, with Schematics, Gerbers, and Design information.



• No Vinculum? No problem a pi-based Vinculum emulator for my Heathkit H8 computer

Emulating a Vinculum VDIP1 IC using a raspberry pi, to communicate with a Heathkit H8 Computer.



• Speech Synthesizer for the Heathkit H8 Computer


• The Trump Card: Zilog Z8000 Coprocessor card for the IBM PC

The Trump Card is a Zilog Z8000 coprocessor/accelerator card for the IBM PC 5150 and clones, detailed by a Steve Ciarcia article in 1984



• Scott’s Zilog Z8000 CP/M-8000 Clover Computer

DIY Zilog Z8000 computer that runs CP/M-8000 with 1MB flash, 1MB RAM, and a couple serial ports.



• A new calibrator and a new amplifier for an old Drake

Drake R-4C crystal calibrator, sherwood-style amplifier, and other modifications



• Raspberry Pi Based DDS-VFO For Drake 4-Line Twins

A DDS-VFO digital synthesizer for Drake 4-Line Twins (T-4XC, R-4B, R-4C, etc). Powered by a raspberry pi. Uses alphanumeric display and rotary encoder.



• Adding a panadapter to a Drake R-4B Ham Radio Receiver


• Heathkit GC-1000 Most Accurate Enigma

Restoring, repairing, and improving the performance of a Heathkit GC-1000 Most Accurate Clock. This clock uses the WWV broadcast signal to automatically set the time.



• Tandy Color Computer Resources


• Sound and Speech boards for the Epson QX-10 CP/M Computer

Speech and Sound add-on cards for the Epson QX-10 CP/M Computer.



• An IDE Adapter for the Epson QX-10 CP/M Computer

A compactflash/ide adapter for the Epson QX-10 CP/M Computer system, uses a slightly patched version of the BIOS drivers for the Comrex Comfiler hard drive.



• Battery operated ESP8266 Wifi Button to trigger my sprinkler system

Use a battery-operated ESP8266 ESP-01 module as a wifi trigger for home automation.



• A basic and RAM board for HP-9000 series computers


• Assembling a thin client to serve as an HPDrive


• Raspberry Pi Floppy Controller Board

This floppy controller hat for the raspberry pi allows you to connect vintage floppy drives (360K, 720K, 1.2MB, 1.44MB, etc) to your raspberry pi model 4B.



• HP 27201A Speech Output Module, first speech synthesizer designed by a major computer manufacturer!

Teardown and reverse engineering of the HP 27201A speech output module, which uses the TMS5220 speech processor IC and was designed to be used with the HP 1000 and HP 3000 series minicomputers.



• The VTEK Small Talk Plus Epson HX-20, World First Laptop — Talking!


• This is Digitalker! … and Jameco JE520 too. Vintage Speech Synthesis.


• Cloning the ET-3404 6809 adapter for the Heathkit ET-3400


• Designing a Memory/IO (ETA-3400) addon for the ET-3400 Trainer


• Overclocking the pi4 with the Blink Blink ICE Tower CPU Cooling Fan


• Supercapacitor Uninterruptable Power Supply (UPS) for Raspberry Pi


• The Hayes Chronograph, a Remake for 2020


• Tandy 1000 Upgrades / PS2-Tandy Keyboard Adapter


• Restoring a Convergent Technologies NGEN PC/Workstation (Burroughs B25 / Unisys)


• Raspberry Pi Controlled DC Load


• Hot Shoe to 1/4-20 Quick Release Magnetic Mount for LumeCube


• Building a Power-over-Ethernet (PoE) Power supply using a DPS5005 module


• Scott’s FrankenNUC: 10Gbe Fiber Network on a 5th Generation Intel NUC 5i7RYH


• RAIN: Redundant Arrays of (In)expensive NUCs


• DIY Wireless Temp/Humid/Pressure sensors with Raspberry Pi Receiver, for monitoring stored 3D printer Filament


• Raspberry Pi 4: Do you need a fan? What’s the best fan for a raspberry pi 4?


• Vacuum Fluorescent Display (VFD) on a Prusa I3 Mk3 Printer


• The Nixie Tube Filadometer – A Nixie Tube Filament Meter for your 3D Printer


• COB LED Panels: 10 watt, 70 watt, and 200 watt.


• Resistive Load, Constant-Current Power Supplies, and a 3D Printed Desk Lamp


• 3D Printer OctoPrint Monitoring with Prometheus and Grafana


• Raspberry pi based indoor air quality monitor


• Building the ultimate USB power distribution system


• Making the e-paper equivalent of an Etch-a-Sketch


• Yet Another Masterplay Clone


• Atari 5200 Playstation 2 Dual-shock controller adapter


• Homemade Atari 5200 Analog Controller


• Scott’s Z80SBC: Z80 Single Board Computer


• Pi-Powered Atari 5200 Multi-ROM Cartridge (MultiCart)


• Raspberry Pi Virtual Floppy for ISA (PC XT/AT) Computers


• Converting a Seeburg 3WA Wallbox into a Remote for a Modern Music Player


• 8-bit ISA DiskOnChip / RTC board


• Measuring USB Power Cable Voltage Drop with my DC Load


• Leia’s LED Clock


• Building a Micro 8088 Single Board Computer


• 8-Bit ISA EMS Board / Flash Disk Board


• PS2-TTLSerial Adapter for RC2014 and MIDI


• Raspberry Pi Midi Hat / Building a Raspberry Pi Midi Jukebox


• Vintage MIDI: Roland MT-32, Roland SC-55, HardMPU, and an Xi 8088


• CTS256A-AL2 Text-To-Speech Board


• ISA Speech Synthesizer board using SP0256A-AL2


• Z80 Retrocomputing 18 – Z180 CPU Board for RC2014


• Z80 Retrocomputing 17: Enhanced Z80 CPU Board for RC2014


• Building an Xi 8088 PC


• Z80 Retrocomputing 16 – Unix on RC2014


• Z80 Retrocomputing 15 – CP/M on RC2014 Revisted, Using RomWBW


• Qume 842 8″ floppy drive with a RC2014 Z80 retrocomputer


• Building a Zeta V2 Single Board Computer


• Z80 Retrocomputing Part 14 – RC2014 Floppy Controller Boards


• Z80 Retrocomputing 13 – RC2014 VFD Display Board


• Z80 Retrocomputing 12 – Talking Nixie Tube Clock


• Z80 Power-on reset circuits


• Z80 retrocomputing 11 – CP/M on the RC2014


• Z80 Retrocomputing 10 – RC2014 CompactFlash board


• Nixie Calculator Update – PCB availability, source code, design notes


• Z80 Retrocomputing 9 – CTC and dual serial ports for RC2014


• Z80 Retrocomputing 8 – Speech Synthesizer for RC2014


• SP0256A-AL2 speech synthesizer chips: Genuine vs Counterfeit.


• Z80 Retrocomputing 7 – RC2014 DAC (Digital To Analog Converter)


• Z80 Retrocomputing 6 – RC2014 TIL311 Front Panel Board


• Z80 Retrocomputing 5 – Single Stepper for RC2014


• Z80 Retrocomputing 4 – Bus Supervisor


• Z80 Retrocomputing 3 – Bus Monitor Board


• Z80 Retrocomputing 2 – Real Time Clock for the RC2014

I developed my first add-on board for the RC2014. This board is a real-time clock and an 8-bit output port. I'll use it to build a Nixie Tube Clock.



• Intro to Z80 Retrocomputing

This is the first in my series of Z80 retrocomputing blog posts. It serves as an introduction. I started by building the RC2014, a popular retrocomputer platform that I found on Tindie.



• Building the Dutchtronix Scope Clock


• Product Reviews: Mooshimeter, Raspberry Pi Black Slices Case, Powerhorse Surface Cleaner


• Magic Eye Tube Audio Spectrum Analyzer

In this post, I put together a magic eye tube spectrum analyzer using my two-tube boards, op-amp boards, and a spectrum analyzer board that uses the BA3830S chip.



• Magic Eye Tube PC Monitor

I thought it would be cool to use magic eye tubes to visualize the activity on my PC, so I threw together a two-tube project that shows CPU utilization and network utilization.



• Magic Eye Tube interfacing with a Raspberry Pi

I discovered magic eye tubes on eBay. I bought a couple of cheap and simple boards and assembled them. Then I tried to see what it would take to control the tubes from a Raspberry Pi.



• DIY Nixie Tube Frequency Counter

I've always wanted a Nixie Tube Frequency Counter, but one has never come up on eBay for a price that I was willing to pay. So I just made my own using the same Nixie Tube boards as the calculator project. I learned a bit about frequency counter front-ends in the process.



• Raspberry Pi Switching Power Supply Shield

There are many times when I want to power one of my Raspberry Pi projects from 12V instead of 5V. I built this switching power supply shield to make it easy to do so.



• Eico 430 Oscilloscope

I bought an Eico 430 Oscilloscope, an old analog scope from the late 50s / early 60s. It's a cathode ray tube scope, with vacuum tubes used throughout. It works amazingly well given its age, and will actually be a useful addition to the bench.