Introduction

I made this to help speed along the process of running hardware tests on the PC Engine console. Previously I had been erasing and rewriting Flash memory chips that fit in a ZIF socket on a development card, which was a tedious process.

Features include:

• 128K to 512K of flash memory for storing the bootloader and other data.
• 512K of NVRAM for program storage.
• High-speed USB interface for rapid development and testing of programs.

Project status

The data bus is heavily loaded in the PC Engine system and cannot drive all the devices on this board. The fix is to add 4.7K ohm pull-down resistors on the data bus to help the integrity of these signals which are weakly driven low. Or modify the PCB layout to include a 74HC245 buffer.

I made several modifications after the board was assembled to support 1.5MB of NVRAM (from a DS1270Y 2MB device) including a 512-byte scratchpad area mapped to the I/O area, and to also allow support for the Sega Master System console.

Files