"Survival" by Stewart F. Rush (1981)

I've created a new MC-10 version of "Survival" aka "Moon Survival Adventure" from David Ahl's 1984 book "Big BASIC Games". I only made minimal changes to get the source code to work properly. Renga in Blue (Jason Dyer) did a blog post about the game which made me aware that a version I had created a while ago (from source found online) was actually a modified version with the authorship attribution changed (as was common back in the day). My new version is a faithful rendition of the source code found in Ahl's book. In fact you should be able to simply type in the following changes recommended by Rush in the description of the game to make it easier:

350 T2=275

360 P1=320

370 P2=75

730 IF T1>485 THEN 2960

740 IF T1>380 THEN 3840

The following line is the specific one that sets the item max to 3 items:

2270 IF C>2 THEN 2390

I wouldn't bother using that one. As Jason makes clear, the game difficulty is set too hard for enjoyable adventuring set at the original numbers. Typing in the first five lines above (i.e. without 2270) should make for a more enjoyable experience.

I made a few other changes. The carried item count is not decremented when you get the fuel and then use it to refuel your rocket. This shrinks your carry limit to 3. I fixed it. Also, the following line was missing from the code listing in the book:

3750 O(6)=14

This "exposes" the location of the de-activator, which is absolutely required to complete the game. Now it will show up at the appropriate time. Jason suggests in his blog post that this is because you have seen the clue in the space station indicating the location of the item, but it is actually just timed to occur at 200 minutes into the adventure. In other words, it appears after you have likely been exploring long enough to have got into the station and back out on to the surface.

In the following screen you will see that I have added some comments at the bottom of the listing that allow for a simple way to modify the game to be played at a more reasonable level:

Just type 9070 and hit enter before typing RUN.  However, this only modifies the oxygen level, line 350 in the list above.  It leaves in place other timed events like the coming of the meteor, that crushes the station at line 730, if you take too long:

I have played the game through using the walkthrough by Garry Francis over on the CASA Solution archive.  Here is the screen just before I blast off to game completion.

If you are looking for an authentic experience of the original 1981 version of the game published in Ahl's 1984 book, it can be played on the Internet Archive: https://archive.org/details/survival_202504