This file describes how to edit your game, be it giving your character 255 shots in your Walther-P4, changing your hitpoints to be 4000 or even changing your location within the dungeon. It is a quite simple process, although it CAN be dangerous so I recommend you make a copy of your Saved Games file and keep it in a spare place (yea, yea, you've heard it before... but it REALLY sucks to lose your file when you've gotten all the way to the suffocation chamber or something.)
Watcha need:
You have to have some sort of sector editor, I've been using Norton Utilites (you can get to it by loading up Norton and then in the Utilities menu its the item which says, Norton Disk Editor.) You need your Pathways Into Darkness Saved Games file, and you need a backup of this file.
Editing Items:
Open up your Saved Games file, or the copy of the same thing. Go to sector 6 (within the file, NOT 6 absolute sectors - that would probably take you into your boot block or something nasty), this is where all the inventory items are kept (for the FIRST game in your list, I haven't figured out where the others are located yet, I haven't the need for it yet. If you figure it out, let me know)
Each item in your inventory is 8 bytes long. A byte consists of a hex "number" so FF is a byte, so is 33 and 2A, etc. You can see (at least within Norton) that there are two sets of 8 on each line. It may be a little confusing as there are four sections on each line. Each one of those sections has 8 single digits in it, in other words four bytes. So you take the left half of the line and there are two sections of four bytes, those left two sections consist of one inventory item. It may take a second for this to sink in, but look at it for a little while, it'll make sense.
The second byte is the item hex code number (the list is below as to which each hex code corresponds to). It is benifical to change a couple copies of Mien Kampf into a clip of ammo, or a potion or something. To do this, just change this byte to the hex number in the list below.
The fourth byte is the condition of the item (either worn or wielded, or just held) hex number. I believe that 00 means you are holding the item (just in your inventory), 01 and 02 either mean word/wielded or held (as in a crystal sense). I haven't botherd to figure out what these actually are as it is just as easy to do that garbage within the game. Modifying this byte is just worthless and is increasing your chance of screwing something up.
The sixth byte is the quantity in hex. This is a handy one if you seem to be running out of ammo (yea, like that would EVER happen in this game... I would often just give myself a couple clips of 255 shots for my Walther, that way I wouldnt think I was cheating - not like giving yourself a violet potion and a ceder box right away, you have to find those!). Compute the hex value with a calculator (I would recommend PCalc) and put it in here... the max is FF (which in decimal is 255). Clips that normally come in x8 (Walther) or x32 (P-41) can be set to x255 without any problems.... Its handy to have a large clip, as reloading takes time.
The Eight byte is the inventory catalog hex number. This is where in your list of items this item lies. I wouldn't recommend modifying this one either, just change it in the game.
Exceptions: When an item is stored in a container (like ammo in a gun or the pearl in a sack...) some bytes are turned into FFFF; the last inventory item does not seem to have a hex catalog number but FFFF in the last two bytes.
To sum up: the safest way of editing in items is simply to change a useless item like Nazi propaganda to the item you desire. To add items to the inventory is possible, but extra care and precaution must be used. It may seem confusing and items may not conform to the descriptions above, but generally I have found that you can easily identify a clip of ammo or a piece of Nazi junk and just change that into what you desire, most everything else just falls into place.
Misc:
As far as your location, your health points, time and the weapon proficiency ratings (together with killed monster points) these are stored in the 4th sector of the file (remember all the items were in the 6th sector).
The X,Y coordinates are stored in the 1868 and 1872 offsets respectivly. Setting these can be dangerous (it would not be good to set yourself in the middle of a wall, or somewhere unescapable)
The level of the dungeon is stored in offset 1875. Remember the modification of the position of the character can potentially send one's character to Virtual Nirvanna (in the middle of nowhere) which could inflict Bad Craziness. It might be worth your while, however, if you have only a minute left in the game and you are on the bottom level of the dungeon to set your level to the top one in order to escape (assuming the top level is where you escape!)
Your character's hitpoints (current hit points, not max) are stored in offset 1877, and the maximum hitpoints are stored in offset 1879. Hitpoints have a limit, 4000. Setting this too high will put you at negitive (first hit you die). Or if you set it too high and get something that would increase your max hitpoints it will go negitive.
Time can be found in offset 1786-1789; these bytes are the hexidecimal number which represents the time passed from the beginning (=00000000) in 60ths of a second. So if you want to go back (or forth) one minute, subtract (or add) to this number E10 (3600 in decimal), for an hour use 34BC0 (21600 decimal), and so on.
Weapon proficiency rating (0-3...0 meaning none, 1 being novice...3 expert) for the six weapon categories are in offsets: 1863, 1895, 1901, 1907 1913, and 1919. Your proficiency goes up when the monsters killed with that weapon reaches a certain point, the amount of monsters that have been killed with each weapon is stored in: 1879, 11891, 1897, 1903, 1909, 1915.
Item List:
Here is the list of items and their corresponding hex code.