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edits
Loading routine "cores": Difference between revisions
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Document the Search Loader(s?).
(Document Search Loader.) |
(Document the Search Loader(s?).) |
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This code has fairly obviously been constructed to have exactly the same runtime as the ROM code, which explains the always failing <code>RET C</code> and <code>NOP</code> (which replaces the <code>RRA</code> of the ROM routine). All the variants which replace the <code>RET NC</code> with a <code>NOP</code> or similar actually have a different runtime as a failing conditional <code>RET</code> is the ''only'' Z80 instruction which takes 5 t-states. | This code has fairly obviously been constructed to have exactly the same runtime as the ROM code, which explains the always failing <code>RET C</code> and <code>NOP</code> (which replaces the <code>RRA</code> of the ROM routine). All the variants which replace the <code>RET NC</code> with a <code>NOP</code> or similar actually have a different runtime as a failing conditional <code>RET</code> is the ''only'' Z80 instruction which takes 5 t-states. | ||
==== "Variant" Search Loader ==== | |||
Used by some late era Gremlin games; so far seen only in [https://spectrumcomputing.co.uk/index.php?cat=96&id=2937 Lotus Esprit Turbo Challenge] and [https://spectrumcomputing.co.uk/index.php?cat=96&id=4660 Space Crusade]. | |||
LD-SAMPLE INC B | |||
RET Z | |||
LD A,7F | |||
IN A,(FE) | |||
XOR C | |||
AND 40 | |||
JR Z,LD-SAMPLE | |||
While this maintains the distinctive <code>AND 40</code> of the Search Loader, I suspect it's actually an independent derivation. | |||
