Eastern Front: Scenario Options

by Ian Chadwick

Those of you fortunate enough to have an Atari have more than likely played Chris Crawford’s deservedly famous wargame — EASTERN FRONT. If you are at all like myself, or any of the many novices to the game I’ve spoken to, you probably found it equally frustrating. It’s a devil of a game to win, even at the best of times.

Chris Crawford was kind enough to provide me with a copy of the source code to EASTERN FRONT for review in another magazine. Armed with his copious and excellent documentation, the game and the source code (plus a special disk utility program), I set to work to create another scenario for EASTERN FRONT. One I could perhaps stand a better chance at winning.

I was, at the time, more of a machine-language novice than I am now, so this looked like a formidable task. However, Crawford himself made the job considerably easier by including many of the elements which I wished to alter in the actual code itself, modified so that they’d have no effect in play.

One of my problems was that I felt under-gunned against the Russians and wanted to add additional units. Well, it happens that there are eleven German and two Axis units written into the code that do not come into the game. This allowed for a fairly straightforward modification then: I had merely to change their turn of arrival from 255 (a non-existent turn, since the game lasts a mere 40 turns!) to the appropriate turn. I checked an order of battle and found that all units but one were to be found in the front lines, June 1941.

Another problem was the Russian replacement rate. Each turn the Russian units added two points to their combat strength: this includes militia units. Historically, nations tend to create new operational units rather than merely reinforce existing ones. Also, units have operational maximums and I discovered many units exceeding even wishful thinking in their growth! One case is the 8th Militia Army sitting on Moscow. It starts off with a reasonable (? well … ) 185 combat strength, but left unmolested, quickly grows to 250 or more, making a militia army one of the most powerful units on the board! I doubt that Yeremenko or any other Russian general would have traded even one weak army corps for ANY militia unit! So in order to reduce the Russian replacement rate. I changed the increment from two to one.

The Finns seemed a trifle useless in the game as they are not allowed to attack, even in conjunction with a German attack on the same unit. Russian units never bother attacking them otherwise, so I wanted to give them a role to play. While historically the Finns were rather less than active offensively compared to the Germans, this isn’t strictly true of their role in the war. I preferred to allow the Finns the capability to launch attacks but restrict myself to allowing attacks only in conjunction with German units. Also, for historical purposes, you should restrict their movement to within two or three squares of their own border.

A further point I questioned was the terrain effects chart built into the code. Crawford attributes a movement value of 18 to infantry moving through cities in dry weather, 24 in mud and 10 in snow. The movement costs for armor are 6.30 and 8 respectively. This seems rather steep for the most part, so I changed these figures to values more in keeping with my own reading and wargaming: infantry at 8, 12 and 10, armor at 6, 16 and 8. You can see that I didn’t have any quarrel with the snow values. I also changed the mud values for mountain/forest squares from 30 for both infantry and armor, to 20 and 25 respectively.

I wasn’t entirely pleased with the defense values for the terrain types either, so I reduced the values of clear terrain by one and incremented the value of the swamp by one.

My final change is to the number of game turns: from 40 to any number up to 255. Crawford built in the codes for the entire year as he had originally designed the game for the entire Russian Front campaign, but reduced it due to size and length of game. One day, maybe, we’ll see an unofficial version he will release with all of the units and years included.

You must realize that many of my decisions are based on my own interpretation of history and my own experience during a decade of wargaming, just as were Crawford’s decisions. I acknowledge his mastery of programming, but I feel fully justified in arguing points of terrain, strengths, unit sizes and other factors. These changes together produce a strong affect on the play of the game, but not quite so radical as they may appear at first. It’s still a rough go for the beginner.

There are other changes I didn’t dare undertake. One is to prevent Russian units from retreating west across the border in the first months of the war. Annoyingly enough, they do this: even into Hungary which was neutral at that time and didn’t enter combat for another month or so. This little oversight in Crawford’s game is an irritation to many people who play his game. I also didn’t bother to change the length of the error buzzer time loop, although I would have dearly loved to have done so!

I’ve listed these changes below: you can make these changes individually or as a whole depending on what you want out of the game. You will need an original copy of EASTERN FRONT and you will have to back up the entire disk onto a clean, formatted disk. Using any of the popular utilities to read and edit disk sectors (such as DISKSCAN from Micromedia or DISK DETECTIVE from Datasoft), you will be able to easily alter EASTERN FRONT as I’ve described above. You should find the game is 109 sectors long and begins at sector 85 ($55). For ease of alteration, I have included both the decimal and the hexadecimal numbers of the sectors and bytes to be changed. If you are at all interested in the rationale behind the game, its mechanics or in just seeing a good example of a well-designed program, I recommend strongly that you get a copy of the source code from the Atari Program Exchange (APEX).


There are thirteen units available to the German player, twelve of which appear in the opening set up as listed below. For the novice. I recommend the addition of all of them. Stronger players may want to add only a few. To add a unit. change the following bytes in sector 118 ($76) from 255 ($FF) to 0:

39Panzer Corps2056($6)
12Infantry Corps10915($0F)
13Infantry Corps7216($10)
20Infantry Corps7017($11)
42Infantry Corps8118($12)
43Infantry Corps13119($13)
53Infantry Corps10220($14)
3Ital Inf Corps5321($15)
52Panzer Corps7233($21)
44Infantry Corps12238($26)
55Infantry Corps7739($27)
6Finn Inf Corps10148($30)

You must also change sector 111 ($6F) from 28 to 29 ($1C to $1 D) to avoid the conflict of having two units in the same square if you decide to include the 39 Panzer Corps, above.

You may also include this unit by changing the 255 ($FF) to 2 in sector 118 ($76):

27Infantry Corps9750($32)


To reduce the Russian replacement rate from two combat strength points per turn to one, change sector 105 ($69) as follows:



To enable the offensive capacity of Finnish units, change sector 101 ($65) as follows:


These bytes should originally be 42 and 43 ($2A, $2B), respectively.


To alter the terrain as described above, change sector 162 ($A2) as below. Other terrain changes are possible; examine the source code listings for a complete description.

Unit:Terrain:Weather:BYTE:CHANGE TO:


To change the defense ratings of terrain as described above, change sector 188 ($BC) as follows:


You can easily alter the game length to any time you see fit by changing sector 170 ($AA), byte 51 ($33). It is 40 ($28) in the original version, I find that 52 ($34) turns make it more interesting.

EASTERN FRONT is an excellent game that lends itself well to the tinkering of software scenario buffs. I hope to create a scenario for 1942 one day when I have time. With luck, someone will get as enthused about the game and do it for me! The system lends itself very well to other wargames; a Western Front game perhaps. or even a Yom Kippur War scenario. Obviously, changes would need to be made to the core algorithms, but Crawford has provided us with a vehicle for growth and expansion should we take him up on it.

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