Now that we have our decoding of the PIC images up to a well-defined point for F15-SE2, it’s time to look and see where else MicroProse has used this format. As we know from the DarkLands document we discovered back on my second post, along with the thread on a Civilization forum, we know that the format was used in those games, albeit in a different form. Lets dig through the archives to see what other titles use the format, and if that format is the same.
A quick aside about my titles. Most of my titles are pop-culture references of some sort, but these can be fairly regional and do not necessarily translate across borders. Today’s title is a prime example. They are meant to be fun references, and understanding the reference is not required. I wanted to mention this with today’s title as it is particularly regional, and one that only my Canadian readers are likely to get. “Heritage Minutes” is a series of 60 second short films that are shown on Canadian television during commercial breaks from time to time since the 1990’s. These shorts focus on particular moments and people throughout Canadian history. They’re fun to watch, very well made, and I highly recommend checking them out if that kind of stuff interests you. [Link]
One of the main goals of my efforts has not only been to decode the format for F15-SE2, but to document it’s use by MicroProse over the years, along with any sub-variants. In order to identify each variant from the others, I’ve decided to denote them by the year of the oldest datestamp I have for the files.
So far we’ve been working with F15-SE2 PIC files (and SPR files, which are just PIC files with an alternate extension) Looking through my collection I have a number of MicroProse games which have PIC files, here’s a quick breakdown with associated dates for the PIC files (and/or SPR files, as we already know those are PIC files as well)
- F-15 Strike Eagle II – 1989
- F-15 Strike Eagle II Desert Storm – 1988-1991
- F-15 Strike Eagle III – 1992
- F-19 – 1988
- F-117A – 1991
- Silent Service 2 – 1990
- Civilization – 1991
- Darklands – 1992
I’m going to go through and discuss them in chronological order here.
F-19 (May 1988)
All the F-19 assets are dated 1988, and is the same format that we’ve been seeing with F15-SE2. F-19 also appears to use the SPR file extension for PIC files, as well as one other SPK. The one SPK file (AIRID.SPK) is different from both the PIC and SPR files in that it appears to contain more than one image worth of data. I haven’t located the boundary condition, but the image below clearly shows that there is more data after the initial image. I suspect the file is simply a concatenation of a number of PIC files together, with the index/offsets encoded elsewhere. This file will be the subject of investigation later. The images in the file appear to be related to the manual image-lookup copy protection scheme the game uses.
F-15 Strike Eagle II (June 1989)
These are the files we’ve been working with so far, and for the most apart are dated 1989, except for two of the SPR variants. Both those are dated 1988 and share the same name, date, and size of their counterparts included with F-19. Running a md5 sum on the duplicate files shows them to have identical signatures. Clearly MicroProse was looking to reuse some assets here.
F-15 Strike Eagle II
-rw-r--r-- 6356 22 Jun 1989 DBICONS.SPR
-rw-r--r-- 3300 29 Jun 1989 F15.SPR
-rw-r--r-- 6744 5 Oct 1988 LIBYA.SPR
-rw-r--r-- 9524 31 May 1989 ME.SPR
-rw-r--r-- 9907 23 Sep 1988 PERSIAN.SPR
-rw-r--r-- 9146 31 May 1989 VN.SPR
MD5 (F15-SE2/LIBYA.SPR) =
fb234541a8fd588684c80417eebbf729
MD5 (F15-SE2/PERSIAN.SPR) =
fff6a0e3d2d16af739d9a36eb413339fF-19
-rw-r--r-- 3352 9 Sep 1988 ARMING.SPR
-rw-r--r-- 9434 23 Sep 1988 CEUROPE.SPR
-rw-r--r-- 6974 30 Sep 1988 DBICONS.SPR
-rw-r--r-- 4227 12 Oct 1988 F19.SPR
-rw-r--r-- 6744 5 Oct 1988 LIBYA.SPR
-rw-r--r-- 6905 6 Oct 1988 MAPS.SPR
-rw-r--r-- 7595 15 Sep 1988 MEDAL.SPR
-rw-r--r-- 7138 23 Sep 1988 NCAPE.SPR
-rw-r--r-- 9907 23 Sep 1988 PERSIAN.SPR
MD5 (F19/LIBYA.SPR) =
fb234541a8fd588684c80417eebbf729
MD5 (F19/PERSIAN.SPR) =
fff6a0e3d2d16af739d9a36eb413339fI checked some of the other assets here, namely the 3D3, 3DG, 3DT, and WLD corresponding to Libya and the Persian Gulf. They all are identical, except for the WLD files. The WLD files while the same name and size, are dated 1989 with F15-SE2, and carry a different signature, so clearly these were updated.
Silent Service 2 (June 1990)
Silent Service is the first place we see an evolution of the PIC format, with assets dated 1990. The game also appears to make use of catalogues which group a number of files together. some of these CAT files hold the some of graphic assets. Getting at the files in the CAT files will take a little work to figure out, Luckily several PIC flies are still left in the open to explore. From what I can see the PIC data we are familiar with already seems to be prefixed with 6 bytes of “header” data. The first 2 bytes seem to always be the 16 bit vale of 0x0007, that is then followed by two more 16 bit values for the width and height of the image. The game also has a number of palette files in the named form of PALETTE.nnn where nnn is a 0 prefixed 3 digit decimal number ranging form 000 to 022. These files are all exactly 768 bytes long, suggesting that all they contain are the 3 byte component RGB values for 256 palette entries.
File: SS-ADS.PIC [8961 bytes]
Offset x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF Decoded Text
0000000x: 07 00 40 01 C8 00 0B 00 20 71 80 07 00 00 41 48 · · @ · · · · · q · · · · A H
0000001x: 1F 0E 1E 38 58 E0 60 03 87 0F 0A 3E 88 08 09 C1 · · · 8 X · ` · · · · > · · · ·
0000002x: BF 7F 01 89 C0 8B 88 11 12 06 8A 0E 0E 12 00 49 · · · · · · · · · · · · · · · I
0000003x: B1 01 C6 8D 01 13 44 A4 38 04 1E 24 02 00 FE 3D · · · · · · D · 8 · · $ · · · =
0140 = 320
00c8 = 200F-15 Strike Eagle II – Desert Storm (Mar 1991)
Desert Storm is a scenario pack update to F15-SE2. It adds a number of assets dating from 1988 to 1991. Just as with base game, more assets have been pulled from F19 here, and are identical in name, size and signature, with only one set being entirely new. There are 4 additional PIC files dated 1991, that are in the newer format that is documented for Darklands and Civilization. These 4 files are for a demo slideshow included with the scenario pack, and are not used by the game itself.
F-15 Strike Eagle II Desert Storm
-rw-r--r-- 9434 23 Sep 1988 CEUROPE.SPR
-rw-r--r-- 9885 14 Mar 1991 JP.SPR
-rw-r--r-- 7138 23 Sep 1988 NCAPE.SPR
MD5 (F15-SE2/CEUROPE.SPR) =
bacf2b850fcc6b592f92f046c89b15c8
MD5 (F15-SE2/NCAPE.SPR) =
a019f6eade84d4d6a2c8034850979c14F-19
-rw-r--r-- 3352 9 Sep 1988 ARMING.SPR
-rw-r--r-- 9434 23 Sep 1988 CEUROPE.SPR
-rw-r--r-- 6974 30 Sep 1988 DBICONS.SPR
-rw-r--r-- 4227 12 Oct 1988 F19.SPR
-rw-r--r-- 6744 5 Oct 1988 LIBYA.SPR
-rw-r--r-- 6905 6 Oct 1988 MAPS.SPR
-rw-r--r-- 7595 15 Sep 1988 MEDAL.SPR
-rw-r--r-- 7138 23 Sep 1988 NCAPE.SPR
-rw-r--r-- 9907 23 Sep 1988 PERSIAN.SPR
MD5 (F19/CEUROPE.SPR) =
bacf2b850fcc6b592f92f046c89b15c8
MD5 (F19/NCAPE.SPR) =
a019f6eade84d4d6a2c8034850979c14F-117A (Aug 1991)
The PIC assets for F-117A appear to be in the same format seen with F19 and F15-SE2, despite being dated 1991. I suspect much of the core game is based on the same code as F19 and F15-SE2. Many of the 3D assets share the same names as those of the ones in F19 and F15-SE2, and some even have matching signatures, but for the most part look to have been rehashed a bit. F117 seems to introduce several new graphical asset files into the mix. It has a PAL file, same format as what Silent Service 2 had, except now the extension is fixed to PAL and the name changes. All the PAL files are exactly 768 bytes, except one, which is an exact multiple of 768. Also new here are PAN files, but they do not appear to be directly related to PIC, or at least not yet, but from their names they clearly are graphic assets. (PAN perhaps stands for PIC Animation?, will have to investigate these further at some point)
Civilization (Nov 1991)
With Civilization came the first titled release that uses the format documented in the Darklands document we found online. Civilization has a massive number PIC and PAL files. Though one thing is the PIC files seem to contain at least one additional block type with an identifier of 'E0' , that is not covered in any of the information we have found so far. Looks to be similar to the palette, or possibly related, but with only single byte entries, indexed with 00 (start?) and FF (end?), possibly monochrome mapping? Looks like more work is to be done still for documenting this version of the format.
File: ADSCREEN.PIC [18930 bytes]
Offset x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF Decoded Text
0000000x: 45 30 02 01 00 FF 55 11 88 33 44 55 66 77 88 99 E 0 · · · · U · · 3 D U f w · ·
0000001x: AA BB CC DD EE FF 99 99 11 FF 77 88 77 DD 77 44 · · · · · · · · · · w · w · w D
0000002x: C4 44 CC 88 CC 44 88 88 85 85 85 55 55 55 55 55 · D · · · D · · · · · U U U U U
0000003x: 55 55 55 55 55 55 88 88 78 78 77 FF FF FF 77 77 U U U U U U · · x x w · · · w w
0102 = 258 bytes (length)Darklands (Jun 1992)
Like Civilization, Darklands also comes with a massive number of files that will take some time to sort through to figure out which ones are image assets. The PIC files that are bare, appear to be as documented in the Darklands file format description we found online, and do not contain the 'E0' Block we see in Civilization. I’ve Identified at least one catalogue (CAT) file that contains images, unclear what blocks are present in those images at this point, though a quick visual scan I only spotted 'X0' image data blocks.
There is one curiosity with Darlkands, one of the PIC assets is in the new format but is dated Dec 1990. Not sure if this is a datestamp error, or just a remnant from early development of the game. Just interesting that this form of the PIC file was not in use anywhere else at the time, so this would be the earliest example technically. I’m going to consider this an exception, and consider 1991 to be the official date for this format, as that’s when the first title with it was released, though it is possible the Darklands version actually predates the Civilization version, despite being released after. Their general format remains the same, so I consider them to be the same version.
F-15 Strike Eagle III (Sep 1992)
The Image assets with F15-SE3 appear to be of the same form as Darklands. No new or alternate formats are immediately obvious.
Note from the future: This is an ongoing effort, and as such certain details are incorrect, and will change over time as more titles using the format are discovered. With that said please note that the designations used here for the variants does change in the future, as newer dates of earliest use become uncovered.Both the PIC90 and PIC91 formats will be discovered to occur a year earlier than they do here, making them PIC89 and PIC90 respectively.
(As of Jun 21 2024)
My analysis of these titles is far from conclusive, nor is it expansive enough of MicroProse titles to be definitive. But given the sampling above, in order to distinguish the various versions I’m going to take them by their first dated year. (except as discussed otherwise) So that leaves us with
- PIC88
- F-19
- F-15 Strike Eagle II
- F-117A
- PIC90 – Appears to add a header with image dimensions to PIC88
- Silent Service II
- PIC91 – Appears to add additional data segment types to PIC90
- Civilization
- Darklands
- F-15 Strike Eagle III
If anyone has any insight into other titles using the format please leave a comment below, and if I can get my hands on the game, or assets, I’ll analyze them and add to the list.
This Post is the ninth in a series of posts surrounding my reverse engineering efforts of the PIC file format that MicroProse used with their games. Specifically F-15 Strike Eagle II (Though I plan to trace the format through other titles to see if and how it changes). To read my other posts on this topic you can use this link to my archive page for the PIC File Format which will contain all my posts to date on the subject.
Ouch my eye! 
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