Notes:The Adventures of Captain Comic (DOS)

This page contains notes for the game The Adventures of Captain Comic (DOS).

Revisions

The Internet Archive has all five revisions under the item TheAdventuresOfCaptainComic:

• sw1988
• R2sw1988
• R3sw1989
• R4sw1989
• R5sw1991

It also has three other versions:

• swh11988 (file_id.diz labels it "Hacked/grafitti version 1"). This is identical to sw1988 except that it has 4 bytes NOPed out for an infinite-lives cheat. (The hack wouldn't have worked in later revisions because of the instant-win mode, which is perhaps why the mode exists, to prevent a trivial infinite-lives hack.)
• swh21988 (file_id.diz labels it "Hacked/grafitti version 2")
• R4a1sw1989 (file_id.diz labels it "Alternate version 1"). This is identical to R4sw1989 except for the startup text. It says that this version is for distribution exclusively through PUBLIC BRAND SOFTWARE.

File Formats

Malvineous has documented the file formats here.

Executable Packing

In every revision, COMIC.EXE is packed with EXEPACK. Revision 1 uses an earlier version of EXEPACK that not all unpackers can handle. Try these ones:

• https://www.bamsoftware.com/software/exepack/
• https://github.com/w4kfu/unEXEPACK

R1swh21988 (a hacked version) doesn't have COMIC.EXE but rather MENU.EXE, and the EXEPACK layer appears to be wrapped in another layer that adds an advertisement for "Red Point".

Reverse Engineering Tools

Various reverse engineering tools, and annotated disassemblies of every revision, are available in my Comic-related Git/git-annex repo:

git clone https://www.bamsoftware.com/git/comic.git
cd comic/
git annex get

-- Mouser (talk) 23:46, 15 December 2019 (EST)

Sound Effects

The format of a sound effect is an array of

struct {
    uint16_t freq_divider;
    uint16_t duration;
};

The 16-bit values are stored little-endian. Each freq_divider divides the Programmable Interval Timer base frequency of 1193182 Hz. For example, a freq_divider of 1c3f would result in an output frequency of 1193182 / 0x1c3f ≈ 165 Hz. The special freq_divider value 0028 indicates a rest. duration is in number of beats; each beat is about 55 ms (one tick of the 18.2 Hz IRQ 0 timer). The end of the sound is marked by a freq_divider of 0000.

Table of offsets to sound effects in the unpacked executable. Assumes that the unpacked executable has an EXE header of 512 bytes. Changed sounds are highlighted.

	R1sw1988	R1swh11988	R2sw1988	R3sw1989	R4a1sw1989	R4sw1989	R5sw1991
title	2521	2521	25a2	25d2	27a2	27a2	29c4
start	2665	2665	2bc0	2bf2	2daa	2d9e
unused	26a5	26a5	2c00	2c32	2dee	2dde
door	eda9	eda9	f309	f339	f4f9	f4e9	fc29
player death	edd1	edd1	f331	f361	f521	f511	fc51
teleport	edf9	edf9	f359	f389	f549	f539	fc79
bonus	ee19	ee19	f379	f3a9	f569	f559	fc99
materialize	ee25	ee25	f385	f3b5	f575	f565	fca5
game over	ee85	ee85	f3e5	f415	f5d5	f5c5	fd05
screen transition	eede	eede	f43e	f46f	f62f	f61f	fd3f
lost life	eefe	eefe	f45e	f48f	f64f	f63f	fd5f
shoot	ef4e	ef4e	f4ae	f4de	f69e	f68e	fdae
enemy death	ef5a	ef5a	f4ba	f4ea	f6aa	f69a	fdba
player damaged	ef71	ef71	f4d1	f501	f6c1	f6b1	fdd1
item get	ef81	ef81	f4e1	f511	f6d1	f6c1	fde1
extra life	ef95	ef95	f4f5	f525	f6e5	f6d5	fdf5