Complete November 1993 floppy image set

The eight-disk collection originally supplied under temp/ is now in install media/floppy_1993_11. The original acquisition contained two alternative track-image formats for disk 1 and seven ordinary raw images for disks 2–8. After comparison, it was consolidated with the older loose/single-disk copies. The retained images are one protected 86F disk 1 and seven raw IMG disks. The historical relocation record stores the supplied names and hashes; the consolidation record records current paths and every removed duplicate.

The nine extracted filesystem files are INSTALL.EXE and DISKA.DAT through DISKH.DAT. The historical comparison report records files, FAT metadata, source hashes, track hashes and nonstandard sectors before consolidation. Current verification checks the consolidated layout. Historical source paths in the earlier reports are intentionally retained as provenance.

Formats and extraction

disk1.86f is 86Box 86F v2.12, which retains encoded floppy tracks and can represent details beyond ordinary sectors. The supplied disk1.mfm was the HxC MFM encoded-track format, identified by its HXCMFM signature. These are two complete representations of disk 1, rather than one image plus an external metadata file. The format layouts are documented in the 86Box specification and HxC's original format definitions.

Both supplied files contained exactly the same encoded bytes on all 160 track sides: 80 cylinders, two heads, 200,000 bit cells per track side. The HxC header specifies 300 RPM and 500 kbit/s. The 86F capture has no separate weak-bit/hole surface-description bitmap.

Disks 2–8 are standard 1,474,560-byte FAT12 images. .ima and .img are alternative filename suffixes for this raw sector layout; renaming them does not convert or alter their content.

For disk 1, the extractor finds the MFM address marks, decodes each sector and checks its ID/data CRC-16. Every standard CHS sector is present exactly once with a valid checksum. The 2,880 standard sectors are assembled only in memory for FAT12 extraction and comparison. No additional raw disk image is saved.

Filesystem extraction validates FAT allocation chains, file extents and the equality of both FAT copies. The files' internal FAT timestamps are preserved. Independent mtools reads match every extracted file. Disk 1 is supplied to mtools through a Linux RAM-only descriptor; no temporary IMG is written.

Nonstandard sectors on disk 1

The track images contain 2,886 sector headers, six beyond the normal 18-sector geometry. All six are on cylinder 0, divided equally between the two heads:

All standard sectors 1–18 on those tracks remain valid. The unusual sector IDs/sizes and checksum failures agree with the source filenames' [cp] copy-protection marking; they are not evidence of damaged installer files. The exact protection scheme and the routines checking it have not been identified here.

The report retains the six nonstandard records' decoded data, ID/data CRCs, calculated CRCs and bit positions. The retained 86F track image preserves the complete encoded representation, including gaps and marks that a plain filesystem or raw-sector extraction cannot preserve. A standard IMG/file copy therefore does not replace that image for investigating the protection.

Comparison with retained media

The installer had already been retained with the standalone disk-1 image. The loose bundle is now consolidated here; existing installed games remain unchanged. The installer difference has also been investigated after decompression, as described below.

Consolidation and installer differences

All eight identical packs now live once in floppy_1993_11/files/. The old floppy_1993_11_loose, floppy_1993_11_disk1 and floppy_1993_11_images media directories have been replaced by this one directory. The redundant standalone raw disk 1 and the equivalent HxC MFM representation were removed. The retained 86F includes all standard sectors and the protection layout. In total, 12 redundant files (18,192,360 bytes) were removed. The distinct loose installer is preserved in alternate_installer/. Its accompanying Windows INSTALL.PIF was inspected and then discarded at the user’s request: it contained personal launch settings, with no installer arguments or custom DOS startup scripts.

The 21,726-byte installer from disk 1 is packed: its loader opens its own compressed overlay and reconstructs the installer in memory. The loose bundle's 30,320-byte EXE is unpacked. A controlled Unicorn comparison executes only that loader, intercepts its own-file reads, and stops at the original installer entry; it does not run the installation program or create another EXE.

The 30,260-byte loaded modules differ in 17 bytes: an initial two-byte segment cache which entry code overwrites, 14 trailing fill bytes, and one code byte. At module offset 0xf21, the disk image's 74 03 (JZ +3) becomes 75 03 (JNZ +3) in the loose installer. This reverses the branch after the protected check; the failure path calls the dialog displaying Please try again with Key Disk. It is a change to the key-disk validation path as well as a difference in executable packing. Both EXEs are retained. Comparison evidence includes hashes, differing offsets and instruction bytes.

The full set now confirms the internal 13 November 1993 dates across all eight matching packs, rather than dating only disk 1. This is filesystem evidence, not an independently established retail release date. The loose bundle's later filesystem timestamps still appear to reflect repackaging. Native FAT times are:

INSTALL.EXE is dated 1993-11-13 17:09:12. The complete set supplies missing original disk images and protection detail, while the floppy resource sweep remains applicable because the installer packs are unchanged.

ARJ redistribution checked on 15 October 2026

The later temp/disk1.arj through disk8.arj acquisition contains files, rather than disk images: DISKA.DAT through DISKH.DAT, plus INSTALL.EXE in the first archive. All eight ARJ archives pass integrity checks. Every game pack is byte-identical to the retained November 1993 files, including their original 13 November timestamps. The 30,320-byte installer is byte-identical to alternate_installer/INSTALL.EXE, whose reversed key-disk check is described above; its archived timestamp is 19 November 1993 at 18:42:42.

The archive headers record creation on 9 April 1994, from 17:34:22 to 17:51:48. This dates the repackaging, not a new game build. There are no new payloads, disk filesystem metadata or protection tracks to retain from this set. Members were decompressed only in memory; no duplicate extracted files were saved. After verification, the user requested removal of the redundant archives: all eight were deleted on 15 October 2026, reclaiming 10,186,920 bytes; the matching retained files remain unchanged. Comparison evidence records all source/member hashes, timestamps, CRCs and exact retained matches.

Reproduction

From the research root:

python3 tools/inspect_floppy_images.py
python3 tools/compare_floppy_installers.py

This uses Python's standard library for the retained 86F/HxC profiles, MFM decoding, CRC checks and FAT12 extraction, plus mtools for independent filesystem checks. It verifies every retained file against the consolidation hashes, checks the retained track stream against the pre-consolidation record, extracts the nine native files and regenerates the current verification report. The separate installer comparison needs Unicorn and regenerates its in-memory comparison evidence. The track readers intentionally reject unsupported profiles rather than silently treating arbitrary floppy formats as this capture.