The Apple Disk ][ interface timing information #Apple #Floppy
The Embedded Microcontroller blog believed the information available online on the Apple ][ disk interface appears to be somewhat incomplete. To fix this, there is now a blog post for the additional information.
I have captured these waveforms from a vintage Apple IIc computer. The IIc has a disk expansion port on the back where you can get easy access to the control signals. Since all of the control signals go to both the internal drive and the expansion external drive, it provides an easy method to snoop on real signals while using the internal drive. Schematics of the Disk II interface circuitry for the Apple II+ here.
The blog has several beautiful timing diagrams to explain how the signals go in different operations.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.