About This File
Back in 2002, Mark Woodmass created a version of "Jet Set Willy" which speeds up the frame rate by replacing the slow LDIR instructions in the JSW game engine with a stack method to copy the screen data to the Spectrum's video RAM. He described the game as being "marginally faster but not as much as he'd hoped for". A ZIP file with his notes and the game in TAP format can be downloaded from http://www.oocities.org/andrewbroad/spectrum/download/fast.zip.
The changes to the game engine provoke a critical problem with the ropes, because the stack-copying code overwrites the rope trajectory data at #8300. John Elliott has released a patch to fix this bug, which can be downloaded from http://www.seasip.info/Jsw/patches.html.
Once the ropes problem has been fixed, the game is still impossible to complete, because it suffers from the four critical bugs which make the original "JSW" incompletable.
The ZIP file of this download contains fixed, completable files of the game in TAP and TZX formats. The file was fixed by applying John Elliott's patch and the four official Software Projects POKEs (#EB47,00 - removes a Fire cell from "Conservatory Roof"; #E9FD,52 - fixes the 'Attic Bug' arrow; #A4C7,0B - moves the invisible item from "First Landing" to "The Hall"; #DE2C,04 - Changes an Earth cell in the Banyan Tree to a Water cell so the tree is climbable).
I did mean to make this ZIP available for download here ever since I created an individual page of this version of the game on JSW Central back in March 2018, but it slipped my mind - I've just remembered it was one of the things I planned to do. So here it is :).