Hey there! That's actually a really insightful question that gets to the heart of how maintenance technicians work with older industrial systems. From what I've found, there are several practical reasons why technicians stick with physical manuals and handwritten notes for legacy Mitsubishi PLC systems:

First off, immediate availability is huge. When you're troubleshooting on the factory floor, you can't afford to wait for a tablet or computer to boot up, log in, and load digital files. Physical manuals are right there when you need them - no passwords, no software crashes, no battery issues.

Then there's the tactile advantage. With physical manuals, technicians can quickly flip through pages, use sticky notes, and make handwritten annotations right next to the relevant diagrams or procedures. These handwritten notes often contain years of accumulated wisdom - specific quirks of particular machines, workarounds for known issues, or personal shortcuts that have proven effective over time.

Legacy systems themselves also play a role. Older Mitsubishi PLC systems might not have modern diagnostic tools or interfaces that work well with digital documentation. The troubleshooting process for these systems often involves hands-on work where paper manuals can be propped up in awkward positions or taken into tight spaces where digital devices would be impractical.

There's also a comfort factor. Many experienced technicians have been using the same physical manuals for decades - they know exactly where to find specific information, and their muscle memory kicks in during high-pressure troubleshooting situations.

Interestingly, while digital documentation offers advantages like searchability and easy updates, the reality on the shop floor often favors the reliability and simplicity of paper-based systems for these legacy applications. It's less about resisting technology and more about what works best when you need to get production running again quickly!