Hardware

Index of hardware projects.


Computers

MC68008 Calculator

MC68008 Calculator

Calculator using the MC68008 CPU.

Z80 Computer

Thumbnail of Update Video #3

From 2019 to 2020 I worked on Z80 based computers. Starting off with tests and demos using glue logic connected to the Z80 bus and ending with a fully functional Z80 computer with NASCOM BASIC.

PIC Surfboard

PIC Surfboard - Front

This is a simple PIC single board computer I made so I could learn PIC assembly. It easily plugs into a breadboard. It features the PIC16F873A microcontroller, a 8MHz TTL oscillator, and a reset button.

8031 Single Board Computer

8031 SBC - Front

This is a single board computer utilizing the 8031 microcontroller. The 8031 is the ROMless version of the 8051. This allows me to modify the program running on the 8031 using an attached EPROM. This SBC easilly connects to a breadboard.

Dorptrum

Dorptrum

Dorptrum is a modular computer system made completely out of off-the-shelf components. It is card based and compatible with the RC2014 bus. All boards are hand wired.

4-Bit Tekkit ALU

A CISC ALU I made in the Minecraft modpack Tekkit.

Mods

Autocoffee

Autocoffee

An automatic coffee maker using a salvaged relay and a Basic Stamp.

Alarm Clock with a Headphone Jack

Alarm Clock

It's what it says on the tin.

Power

Audi Internal Battery Charger

Charger

I like my car. I like driving my car. However, due to COVID, I do not have much reason to drive my car. So that means its often sitting outside. And sometimes when I try to start it after it has been sitting outside for a while, the battery is flat. This is very annoying. So I came up with a solution, install a battery charger inside of the car. Unlike most battery chargers this one would be internal and would be installed in the trunk and wired directly to the battery. The circuit is fused for safety. All that is needed to charge the car is the 120V power cable to be plugged into an electrical outlet.

9V to 5V Power Supply

9V to 5V Power Supply

A simple 9V battery to 5V power supply.

Digital

Boolean Function Generator

Boolean Function Generator - Top

This is a boolean function generator utilizing a SN74150N 16-to-1 multiplexer I got from a scrap metal lot on ebay. Using the DIP switches, any 16 bit serial signal can be generated. This is very useful when it comes to testing UARTs as it much more compact than carrying around a palmtop computer and my TTL to RS232 Adapter.

555 PWM Generator

555 PWM Generator - Top

This is a device that generates a PWM signal. The width of the pulses is controlled by the potentiometer.

Glue Logic Tester

Glue Logic Tester - Front

This is a device that tests quad gate 74xx series chips. It generates a truth table which is displayed by the four LEDs. It is powered by the two pin 5V power connector on the bottom. It is useful for testing salvaged glue logic chips to make sure they still work. However, it does not test each individual gate with all possible values, instead only testing each gate with unique inputs..

Glue Logic Random Number Generator

Glue Logic RNG - Front

This is a random number generator made using only 3 glue logic ICs. How it works is that the 74161 4-bit counter constantly counts up at a rate of 1,000,000 times per second. When the button is pressed, the clock is disconnected from the counter through a AND gate implemented using NAND logic (7400). The number stopped on then is fed into the BCD to 7-segment decoder which drives the 7-segment display.

TTL to RS232 Adapter

RS232 Adapter - Front

This is a 5V TTL Serial to RS232 adapter. It allows a UART like the MC6850 (which runs on 5V logic) to connect to a 12V RS232 port. This is super useful if you have a palmtop computer like the HP 300LX because you can use the palmtop as a serial terminal instead of having to lug a laptop to use as a serial terminal.

Analog

Ring Detector

Ring Detector - Final Schematic (Annotated)

A device that blinks a LED when there is an incoming call on a landline. If someone gets a lot of calls, it might get annoying hearing the phone ring constantly. This device provides a silent method of knowing when there is an incoming call. It is also compatible with teletypes. It is far less expensive than the products currently on the market that accomplish the same task. It can be used in conjunction with Microphone.

Sound

Microphone

Microphone Board

A simple, small telephone made out of old components.

SAA1099 Experiments

SAA1099

Experiments with the SAA1099 sound generator.