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using Manic Miner and Jet Set Willy game engines
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Message: 6936
Author: rushforthian
Date: 14/11/2016
Subject: Re: Broadsoft Lifts v0.2: Hex-editor type-in
I just conducted some very interesting experimentation!
With the Broadsoft Lift Patch in place, ropes can indeed cause 'random' teleportation (both upwards and downwards!)
Furthermore, the ropes can be rendered fatal by the Lift Patch - e.g. if Willy climbs up the rope in the Swimming Pool to the Orangery above, drops back down to land 'safely' on the rope, then tries to climb straight back up the rope, he is unfairly killed when he gets near to the top! (Presumably because the Airborne Status Indicator at #85D1 isn't reset to zero whenever Willy lands on a rope.)
Fortunately, there is an easy fix for this 'glitch' [N.B. I've only considered the JSW48 code]:
- change the Call opcode at #91B6 to a Jump (JP #96FD);
- at the end of the 'lift' routine (which I suppose is no longer technically a 'routine'), replace the 'C9' at #9760 with a Jump to #91B9;
- edit the destination of the Jumps at #9125 and #9130 (the end of the 'Move the rope' code) to '#975D';
- for 'elegance', also change the Jump at #90CC (if we're considering an arrow or a blank guardian) to point straight to the instruction at #975D (the LD DE, #0008 which was formerly at #91B6).
P.S. The experimentation described above was conducted with the Adjacent Ropes (New) Patch in place, so any adjacent-guardian related effects can be discounted as a potential cause of the quirky behaviour.
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