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.

 PERMSSN    UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
drwxr-xr-x     0/0           0       0 ****** -lhd- 0000 Sep  6 18:36 OpLem_v1.0/
drwxr-xr-x     0/0           0       0 ****** -lhd- 0000 Sep  6 18:36 OpLem_v1.0/Data/
-rw-r--r--     0/0        9236   14622  63.2% -lh5- 3eb2 Sep  6 18:36 OpLem_v1.0/Data/001A
-rw-r--r--     0/0       60881  110048  55.3% -lh5- a8e6 Sep  6 18:36 OpLem_v1.0/Data/001B
-rw-r--r--     0/0        1722    3432  50.2% -lh5- 320d Sep  6 18:36 OpLem_v1.0/Data/001C
-rw-r--r--     0/0       14600   20160  72.4% -lh5- 2184 Sep  6 18:36 OpLem_v1.0/Data/001D
-rw-r--r--     0/0       10305   15336  67.2% -lh5- eda2 Sep  6 18:36 OpLem_v1.0/Data/001E
-rw-r--r--     0/0        1035    5134  20.2% -lh5- 2302 Sep  6 18:36 OpLem_v1.0/Data/002A
-rw-r--r--     0/0        2990    5546  53.9% -lh5- 2c5d Sep  6 18:36 OpLem_v1.0/Data/002B
-rw-r--r--     0/0        3545    7032  50.4% -lh5- ebea Sep  6 18:36 OpLem_v1.0/Data/002C
-rw-r--r--     0/0        3055    6236  49.0% -lh5- b61e Sep  6 18:36 OpLem_v1.0/Data/002D
-rw-r--r--     0/0        2755    4428  62.2% -lh5- aecc Sep  6 18:36 OpLem_v1.0/Data/002E
-rw-r--r--     0/0        7385    9974  74.0% -lh5- d008 Sep  6 18:36 OpLem_v1.0/Data/002F
-rw-r--r--     0/0        6794    9688  70.1% -lh5- b1a3 Sep  6 18:36 OpLem_v1.0/Data/002G
-rw-r--r--     0/0        5319    8706  61.1% -lh5- 6f37 Sep  6 18:36 OpLem_v1.0/Data/002H
-rw-r--r--     0/0        2008    6028  33.3% -lh5- f968 Sep  6 18:36 OpLem_v1.0/Data/002I
-rw-r--r--     0/0        5858    9404  62.3% -lh5- 3876 Sep  6 18:36 OpLem_v1.0/Data/002J
-rw-r--r--     0/0        4079    7088  57.5% -lh5- 7edf Sep  6 18:36 OpLem_v1.0/Data/002K
-rw-r--r--     0/0        9893   14622  67.7% -lh5- 80a9 Sep  6 18:36 OpLem_v1.0/Data/002M
-rw-r--r--     0/0       19209   24844  77.3% -lh5- b19e Sep  6 18:36 OpLem_v1.0/Data/002N
-rw-r--r--     0/0       32628   63894  51.1% -lh5- 25f0 Sep  6 18:36 OpLem_v1.0/Data/002O
-rw-r--r--     0/0        7834   14024  55.9% -lh5- 61d7 Sep  6 18:36 OpLem_v1.0/Data/002P
-rw-r--r--     0/0       33418   41362  80.8% -lh5- 686a Sep  6 18:36 OpLem_v1.0/Data/003A
-rw-r--r--     0/0       34468   41028  84.0% -lh5- 3425 Sep  6 18:36 OpLem_v1.0/Data/003B
-rw-r--r--     0/0       33103   40822  81.1% -lh5- 170f Sep  6 18:36 OpLem_v1.0/Data/003C
-rw-r--r--     0/0       30926   39778  77.7% -lh5- 7815 Sep  6 18:36 OpLem_v1.0/Data/003D
-rw-r--r--     0/0        3487    9182  38.0% -lh5- 1d93 Sep  6 18:36 OpLem_v1.0/Docs.txt
-rw-r--r--     0/0         547    1514  36.1% -lh5- 185e Sep  6 18:36 OpLem_v1.0/Docs.txt.info
-rw-r--r--     0/0         247     548  45.1% -lh5- 100f Sep  6 18:36 OpLem_v1.0/OCSGuard
-rw-r--r--     0/0       81550  180108  45.3% -lh5- 0a7a Sep  6 18:36 OpLem_v1.0/OpLem
-rw-r--r--     0/0         514     992  51.8% -lh5- ee0d Sep  6 18:36 OpLem_v1.0/OperationLemming
-rw-r--r--     0/0        1560    3444  45.3% -lh5- b73d Sep  6 18:36 OpLem_v1.0/OperationLemming.info
-rw-r--r--     0/0        2620    5926  44.2% -lh5- ee99 Sep  6 18:36 OpLem_v1.0/ReadMe.txt
-rw-r--r--     0/0         547    1514  36.1% -lh5- 185e Sep  6 18:36 OpLem_v1.0/ReadMe.txt.info
-rw-r--r--     0/0         218     508  42.9% -lh5- 0286 Sep  6 18:36 OpLem_v1.0/RunOCS
drwxr-xr-x     0/0           0       0 ****** -lhd- 0000 Sep  6 18:36 OpLem_v1.0/Source/
-rw-r--r--     0/0        1327    7259  18.3% -lh5- 6e89 Sep  6 18:36 OpLem_v1.0/Source/OCSGuard.asm
-rw-r--r--     0/0        1228    6808  18.0% -lh5- b8c6 Sep  6 18:36 OpLem_v1.0/Source/RunOCS.asm
-rw-r--r--     0/0        1312    3205  40.9% -lh5- 100d Sep  6 18:36 OpLem_v1.0/Source/build_ocsguard.py
-rw-r--r--     0/0        1422    3833  37.1% -lh5- 842d Sep  6 18:36 OpLem_v1.0/Source/build_runocs.py
-rw-r--r--     0/0         336     894  37.6% -lh5- 3db3 Sep  6 18:36 OpLem_v1.0.info
-rw-r--r--     0/0        1596    3070  52.0% -lh5- ec23 Sep  6 18:36 OperationLemming.readme
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total        42 files  441557  752041  58.7%            Sep  9 03:01