rehsd

On my 65265 MCU build, I was curious what it would take to get basic speech capabilities. As I researched this, having the 65265 directly generate speech did not seem like the right approach, primarily due to the CPU-intensive nature of speech synthesis. Rather, a dedicated speech synthesis chip was likely a better approach. Doing a cursory search, I found these as potential options: General Instrument / Microchip SP0256 Family (SP0256‑AL2) Texas Instruments LPC Speech Chips

As my W65C265S hardware build is coming along well, I would like to develop an operating system (OS) for it. While I have done miscellaneous 65xxx development over the years, my code has always been a mishmash of routines. The closest I have come to better understanding operating systems is implementing FreeDOS on my 286/386 builds, where I was adding core BIOS routines to support FreeDOS. So, can I hack my way through this and develop and operating system? Time will tell. So

Continuing my W65C265S project series, I am at a nice milestone where I have a second version of a PCB (actually, a pair of PCBs) -- with significantly expanded functionality from my first PCB. For more background on my work on this up to this point, check out rehsdonline.com/post/w65c265s-single-board-computer . My goal in this post is to work through the two PCBs in the rendering below. This post will be updated as I work through the design and build. [February 07, 2026] I

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