Here are a couple more useful links:
J.G. Harston's page:
Geoff Eddy's Patch Vectors:
However, in the latter, I have noticed a couple of errors.
Firstly, the PVs that change Willy's colour in 'Willy Takes a Trip' (Rooms 69, 61 and 62) all contain (directly or indirectly) several Calls or Jumps to #9673. However, the pertinent sub-routine in the Geoff Mode disassembly (link below) seems to start at #9679 (ending at #967F).
Secondly, the PVs in Rooms 10 and 53 of 'Willy Takes a Trip' both call up #97C8 to print a room element, but the 'Print the room' routine in the Geoff Mode disassembly is at #8D33-#8DB0.
Geoff Mode disassembly:
Ian, thanks for this info.
You are referring to Room 59 (not 69), besides 61 and 62.
I believe these are not errors. The thing is that the disassembly may not (actually I think: does not) reflect exactly the code in all of Geoff's games.
I suspect (without analysing it right now) that the disassembly may have been done on the basis of his first game, "J4 (The Fourth Remix)". In his later two games there must have been some slight changes, and in the fourth game there must be many changes (as it's the so-called Geoff Mode 2).
The PVs disassemblies have to be analysed by looking at the actual code of each game in question rather than by comparing them to the disassembly of Geoff Mode.
In case of "Willy Takes a Trip" the pertinent code which is called indeed starts at #9763.
Also, the printing routine (which I believe is something Geoff wrote, I don't believe it exists in the original "JSW") used by PVs in the rooms 10 and 53 of "Willy Takes a Trip" is where the PV disassembly indicates. I can testify to it, because I copied it into "WNM SE" and it works just fine .