Flash Programmer

Copyright © 2021 by Dan WIlson

This is a simple PCB, firmware, and software that can read and write binary image files to the Microchip SST39 series of flash ROMs. These flash ROMs are one of the very few flash ROMs on the market that are still active production and in DIP packages, making them a popular replacement for the difficult-to-find AT28 series of EEPROMs.

This programmer handles the SST39SF010, SST39SF020, and SST39SF040 parts (128KB, 256KB, and 512KB respectively).

This programmer’s PCB design uses all through-hole parts for easy soldering. The general design is based on Ben Eater’s Arduino-based Flash Programmer, using a microcontroller and shift registers to increase the number of available outputs. Ben’s microcontroller is the Arduino Nano, here I’m using a Microchip PIC16.

The firmware on the PIC16 implements a command protocol that runs over a serial interface. The board contains a simple RS232 serial level shifter that allows the PC to communicate with the microcontroller.

On the PC, a command line program is provided to read and write to the flash memory. The command line program is written in Visual C# with Visual Studio.

You can order the PCBs directly from Oshpark with this link.

Several different licenses apply to this repository and the files within.

All schematics and circuit board designs in the project (all KiCAD files) are licensed under the CERN Open Hardware License Version 2 - Strongly Reciprocal (CERN-OHL-S).

All software and firmware code in the project (all MPLAB and Visual Studio files) are licensed under the GNU Affero General Public License v3.0 (AGPL 3.0).

Bill of Materials, pictures, and documentation (i.e. all other files not covered by the other two licenses above) are licensed under the Creative Commons Attribution Share Alike 4.0 International License (CC-BY-SA-4.0).