Well, finally got a chunk of free time to get back to my ‘Model 100 school’. My goal is to learn about these m100s through hands-on learning.
A new friend (Hi Larry) sent me his ailing m100 to further my education. Who knows? Maybe I can get it running again — it’s a nice looking machine!
About a month ago I first opened it up and gave it a visual inspection. Clean and no obvious sign of capacitors failing or failed. The Memory battery is starting to show signs of crystal growth, so it’ll be coming out soon.
Upon power up, the unit shows a screen of scrambled pixels. Not garbled characters, just pixels, or missing pixels.
And that’s where I left it a month ago.
Tonight I managed to get my workbench in shape (my first oscilloscope — more learning!) and open the m100 and start taking some basic readings.
- VDD 5.179
- VEE ‑4.961
- VB 5.144
Next, start tracing down the RESET signal.