Color Without Color: Apple II Computer Graphics #Apple #Hacking #Video #AppleII

Color Without Color: Apple II Computer Graphics

A great write-up by paleotronic on how Steve Wozniak was able to get color from monochrome for the Apple II computer:

Released in 1977, the Apple II was one of the first personal computers marketed towards households rather than businesses. It was a complete computer – it had a keyboard for data entry and the ability to connect to a CRT monitor or a television set. However, unlike its competitors, the TRS-80 Model I and the Commodore PET 2001, the Apple II was able to display colour – but remarkably, it accomplished this without a dedicated colour video chip. The Apple II’s video hardware is actually monochrome!

So how does it display colours? The Apple II’s designer, Apple co-founder and chief engineer Steve Wozniak, discovered that if he repeated portions of the outgoing digital luminance signal (black or white) and injected it into the “colorburst” or NTSC colour signal, various patterns of pixels produced lines of different colours.

The “native” monochrome resolution of the Apple II is 280 pixels wide by 192 pixels deep. Each pixel is either on (1) or off (0). Steve found that using blocks of two pixels, he would get black (00), purple (01), green (10) and white (11). By shifting the timing of the colour signal, Steve was able to get an additional two colours, blue (01) and orange (10). This left him with a “high resolution” graphics mode (HGR) of 140×192.

Read more in the article. Subscribe to paleotronic.


Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat and our Discord!

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Join over 38,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org


New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — New Products 11/15/2024 Featuring Adafruit bq25185 USB / DC / Solar Charger with 3.3V Buck Board! (Video)

Python for Microcontrollers – Adafruit Daily — Python on Microcontrollers Newsletter: A New Arduino MicroPython Package Manager, How-Tos and Much More! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

EYE on NPI – Adafruit Daily — EYE on NPI Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

Adafruit IoT Monthly — The 2024 Recap Issue!

Maker Business – Adafruit Daily — Apple to build another chip at TSMC Arizona

Electronics – Adafruit Daily — SMT Tip – Stop moving around!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !


No Comments

No comments yet.

Sorry, the comment form is closed at this time.