You are correct. For some reason, I thought the S-C lands were commons in Ice Age. In that case, they'll only show up in Coldsnap.
As for Alpha, I didn't feel like differentiating. To generate the packs, I first filter the cards out from the text checklists that were provided by WotC (and can now be found
here at Crystal Keep. Those lists combine Alpha, Beta and Unlimited, so I just left it as such. I suppose I could split up the three sets and drop CoP: Black and Volcanic Island from Alpha, but I really don't feel like it.
If you want to look at the program, I can send it to you, but you probably wouldn't understand it. The software I used was developed by my dad for his first business, as a data processing and graphing tool. He intended to sell it as a CAD tool, but that business went under and now we only use it internally, on our Linux system.
The basic algorithm, I originally wrote as a deck shuffler, but found that it was easily adapted for generating boosters. It looks like this:
1) Accept input file (set of cards) and assign each to a value in an array
2) Generate a random number between 1 and the highest value of the array
3) Output the value (card name) at that point in the array
4) Replace that value with the value at the highest point in the array
5) Return to step 2 until all the values have been output
At this point, I have a new list of all the cards, but in a random order. I run this three times, once for each rarity, then I just pull the number of cards I want in each booster off the top of the lists.
