I guess I'll forward this without my picture. It's a shame this list won't take attachments bigger than 64k. Does this mean that everyone who wants to share this sort of thing goes over to Facebook? Or where? ---------- Forwarded message ---------- From: "Josh Malone" <[email protected]> Date: May 8, 2017 10:19 PM Subject: RAM issues continued To: "Model 100 Discussion" <[email protected]> Cc:
So, I've finally made a breakthrough in my 102 RAM issue. If you recall, my > 32k machine cold - started on me one day and from then on it only showed > 24k. I replaced the sram to no avail. After that pain in the @$$, i kinda > have up for a while. > > I finally got my hands on a hot air station, and I was able to wing a pin > on the M5 mux so i could scope it independently. Sure enough, no activity > on the line. So the decoder circuit was never enabling the option RAM. I > was so proud of my rework! > > So, my next step is to track down a replacement for the mux. I removed the > chip without to much difficulty. It's a 40H139F. Hopefully not too hard to > source in that package. > > Wish me luck! > > - Josh >
