Can't say I have - time to update my JSW disassembly TODO list.
By the way, I checked and this is the only instance of a non-conveyor tile being affected by the Cell-Graphics bug.
Thanks Richard, that's useful to know.
Have you checked whether the Cell-Graphics Bug affects any cavern elements in Manic Miner? I can't think of any examples off the top of my head, but it can occur in theory because the same erroneous use of a CPIR command is present in the routine which draws the layout to the pixel-buffer.
I know that there are instances in Andrew Broad's mirror-imaged versions of both Manic Miner and Jet Set Willy - in the latter, there are new instances that arise because the graphic bytes are all laterally-inverted (Fire cells in The Attic, for example, whose attribute byte matches the penultimate graphic byte of the Earth cells if it's inverted), whilst I believe the same mirroring process either changes the nature of some of the existing examples of conveyor corruption, or in some cases 'cures' them altogether (i.e. prevents them from arising).
Here's another thing for your JSW TODO list (although I may have already mentioned this - can't remember - or perhaps you have already mentioned it in the JSW disassembly):
Several vertical guardians in Jet Set Willy can extend below the bottom
of their specified range (one or two of the bats that lurk between the columns of Fire cells in 'At the Foot of the MegaTree' do so, for example). It happens if the difference between the guardian's upper and lower bounds isn't exactly divisible its vertical speed. The 'out of bounds' situation only prevails for a single time-frame, whilst the guardian's direction of travel is being reversed.
N.B. It doesn't happen at the top
of a vertical guardian's specified range, because there is a specific command at #91A8 which sets the guardian's definition byte 06 as a 'hard' upper bound.
One other little point that you might be interested in, Richard - please see the post at the following link, which gives a possible explanation for the existence of a redundant instruction that is present in the 'Lose a Life' routine of both JSW (#8C19) and
Manic Miner (#8925). You describe the instruction thus: "Set bit 4 of A (for no apparent reason)".http://jswmm.co.uk/t...-in-jsw/?p=7817
Edited by IRF, 18 November 2017 - 10:07 AM.