OperationLemming 1.0

Operation Lemming (1991) HD/WB edition

Short:        Operation Lemming (1991) HD/WB edition
Author:       Chris Foote / Infinity (game); Afrotechmods and Claude (HD edition)
Uploader:     afro afrotechmods com
Type:         game/shoot
Version:      1.0
Requires:     1 MB RAM, OCS/ECS/AGA, Workbench 2.0+ (C:IconX, C:Assign, C:CPU)
Architecture: m68k-amigaos >= 2.0.4
Distribution: Aminet

Operation Lemming is Chris Foote's 1991 AMOS charityware shoot-'em-up:
lemmings pour out of a trapdoor, you shoot them before they reach the
exit, 12 levels, digitised sound, music by Janne Leinonen, graphics by
Ken Evans and friends. It was a well-known PD disk in its day (CYB
Computers / 17 Bit and other libraries). If you enjoy it, the author
asks for a donation to the Royal National Institute for the Blind.

This is the original V1.0 converted so it can be copied to a hard disk
and started from a Workbench icon on any Amiga, including accelerated
and AGA machines.

What is in the drawer
---------------------
- The game and its data, byte for byte as on the floppy, except that
  the PowerPacker self-extractor has been removed from the executable.
- A launcher icon (the author's own hard disk icon) running a small
  script: it assigns OpLem: to the drawer, switches the CPU caches off
  for the game and back on afterwards, and starts the game through two
  tiny helpers that keep the AGA display registers (FMODE, BPLCON3/4)
  at OCS defaults while the game runs.
- The author's original documentation as a text file.
- Source (build scripts and disassembly listings) for the two helpers.

Why the helpers are needed
--------------------------
The game itself is a well-behaved AmigaOS program (no track loader, no
copy protection, so no WHDLoad needed), but it is 1991 68000 code:

- The original self-extracting executable and the AMOS runtime crash
  with a Software Failure on 68030/040/060 boards when the CPU caches
  are on. The launcher uses the standard C:CPU command to switch them
  off while the game runs.
- The AMOS runtime builds its own OCS copper list and never touches the
  AGA registers, so under a DBLPAL/Multiscan Workbench the picture is
  torn into vertical strips. The helpers reset those registers before
  the game starts and re-apply them on every vertical blank.

Tested on a real A1200 with Blizzard 1260 (68060), AmigaOS 3.2.3 and a
DBLPAL Workbench, and on an emulated 68020 A1200 with Kickstart 3.2.3.

Installation
------------
Extract the archive anywhere on your hard disk, open the OpLem_v1.0
drawer and double-click "OperationLemming". A small window opens; when
you have finished playing, press RETURN in it to restore the caches and
the display. Details in ReadMe.txt inside the drawer.

All files were checked with xvs.library (the VirusZ III engine).

This conversion was vibecoded with Claude: the disk analysis, launcher,
the two helper programs and the documentation were produced in a Claude
Code session with Anthropic's Claude, directed and tested on real
hardware by the uploader. The game itself is untouched 1991 work by
Chris Foote and friends.