rehsd

When I first started working with the W65C265SXB board, I was trying to get interrupts to work and was having no luck getting the interrupt service routine (ISR) to run. My setup was a simple momentary switch pulling down P41 (IRQB interrupt) or P64 (negative edge P64 interrupt). As I reviewed the sample LEDP72.asm that was included with the WDC Tools, I found vectors defined at the end of the file. Notice the Shadow_VECTORS section at $7EE0 and the vectors section at $FFE0

As I've been working on my W65C265S single-board-computer (SBC) project (see rehsdonline.com/post/w65c265s-single-board-computer ), one of the greater mysteries is the parallel interface bus (PIB). I've found limited information about the PIB, other than some basics in the '265 data sheet. I'm hopeful to get the PIB implemented in the latest phase of my '265 SBC project. Here, I will collect information that should be helpful in my goal of implementing PIB for a dual-265 SBC

It has been a few years since I have worked with the 6502 and 65816 processors. Most recently, my focus has been learning about FPGAs and developing my own FPGA PCB . Along the way, I designed some retro 286 and 386 systems, dabbled with a variety of microcontrollers, and learned more about PCB design. I thought it might be fun to build a single-board computer (SBC) based on the W65C265S microcontroller from The Western Design Center (WDC). This post will be updated as I wo