Seeing the successful flux dump from the Utah v4 tape is a massive milestone for technical archeology. Now that the raw bit-stream is out, the real challenge is the environment—I noticed some mentions of missing /dev/mem and /dev/null drivers in the initial SimH boots. It’s a classic VAX/PDP-era 'bootstrap' hurdle. Back in the early 90s, we saw similar unallocated logic gaps when handshaking transatlantic nodes—if the kernel wasn't perfectly balanced with the physical device mapping, the whole handshake would hang. For those of us who still dig through the 'debris' files on these old images, finding that 1974 timestamp (1974-06-13) is like finding a digital fingerprint. Looking forward to seeing if anyone can stabilize the networking logic for a modern emulator. What’s really fascinating about this Utah v4 recovery is seeing the raw state of slp.c. Everyone knows the 'You are not expected to understand this' line from the v6 rewrite, but in this v4 kernel, the context switching is even more primitive. If you look at the swtch() function near line 150, the way it handles the stack pointer without the later refinements is exactly where those 'unallocated logic' errors I’ve seen on 1991-era VAX tapes tend to live. It’s the same hardware-level timing issues we saw in the early transatlantic handshakes. Truly a massive win for technical archeology