I recently added basic SPI support to my 80286 system with the help of a W65C22S Versatile Interface Adapter (VIA).

Additional Reading About SPI

• Introduction to SPI Interface | Analog Devices

• Serial Peripheral Interface (SPI) - SparkFun Learn

• [Ben Eater] SPI: The serial peripheral interface - YouTube

PSoC Configuration

I am currently using a programmable system-on-chip (PSoC) from Cypress to handle address decoding. Below is the current configuration of the PSoC.

Schematic

The following schematic is as of 23 November 2022.

Assembly Code

This assembly I used during this video is available on my GitHub: Assembly Used in Video.

Data Sheets

• W65C22S (westerndesigncenter.com)

• MAX7219/MAX7221 - Serially Interfaced, 8-Digit LED Display Drivers (maximintegrated.com)

SPI + Arduino Nano = Serial Debugger

x86/g1_20221127.asm at main · rehsd/x86 (github.com)

x86/SPI_80286_Nano.ino at main · rehsd/x86 (github.com)

SD Card Support

I have now added support to read from an SD card.

I have an older post that contains some of my previous (troubleshooting) work with SPI and SD cards. See Calling All SPI SD Card Wizards: Troubleshooting SD Card Access with SPI (rehsdonline.com).

The assembly code used in the above video is available here: x86/g1_20221130.asm at main · rehsd/x86 · GitHub.