Brainteasers: Sir Francis Drake

By Genevieve Ludinski

Originally published in EUG #54

Here's the third in EUG's continuing series of bemusing and occasionally interesting puzzle game series. This issue presents two of the author's best, spruced up with the necessary instructions. A compilation of all of G. Ludinski's Brainteasers (29 in all!) is also now available from EUG HQ across all disk formats.


This is an authentic historical adventure game based on Francis Drake's circumnavigation of the world, from 1577 to 1580. As you travel in the footsteps of Elizabeth I's free-booting adventurers, you will encounter the same problems and challenges as Drake.

Drake sailed in search of the elusive North West Passage that would allow him access to the Pacific, and the galleons of the Spanish Empire. As history books will already have told you, he did not find the object of his quest, but he did find much more. And so will you as you sail into the Francis Adventure Game.

How To Play

On the map you will see your position marked by a white sailing ship, docked near the port of Lima.

Every time you use this game, the dangers and treasures will be located in different parts of the ocean, so do not think that you can predict your moves too easily. We didn't feel that it was fair, however, to move the rocks, reefs and Spanish galleons, so try and remember their positions. It will help you considerably.

You must follow Drake's route by first travelling to the port known as New Albion and thence onward, past Java, to the bottom left hand corner of the map.

Your aim is to reach the bottom of the map with at least four times the amount of cargo with which you began. If you achieve this feat of daring then you will, naturally, be rewarded by the gift of a knighthood from your grateful, and avaricious, Queen.

You move using the cursor keys.

If you input wrong information, the cursor will return to the left hand side of the screen and wait for accurate information. Your screen will then be cleared of your previous false data input.

At intervals you will be told the situation at sea and asked which action you would like to take, from the choices shown.

Remember to consider your options carefully as to the amounts of cargo, supplies, cannon balls and crew conditions.

Damage rating is based on a 1 to 10 scale. If you are damaged to the level of 10 then I'm afraid it's into the sea for you, as the Golden Hind settles gently below your feet.

Do your best as the present Government is emptyinh the coffers more quickly than you are filling them.

As this program is a complex one, it loads in two parts and there is a short pause before the action starts as data is arranged in memory.

Programming Hints

If you find the adventure too easy, then reduce the cargo (CA), supplies (SU), crew (CR) and/or cannon balls (BA) that you start with. They are on line 410 of the second program ("U.DRAKE2"). If you find that knighthood escapes you, then reduce the 400 in line 480.


This program is one where you should deny yourself, and any other player, the use of paper and pencil if you really want some mental exercise.

The screen will display a four by four matrix of numbers to the left hand side. On the right hand side will be shown a number, or numbers, in red.

You have to combine two, or more, of the numbers in either a row or a column to arrive at the same figure as the red number. But your combination may not 'jump' any number. The sequence you enter must be a progressive one.

How To Play

To reach your answer you may use any of the following operators:

+ plus
- minus
* multiplication
/ division
^ to the power of
SQR() square root of

For example, if the red number is 1 and there is a row of 9 2 4 8, you could enter:

This, followed by RETURN, would be correct.

If you answer incorrectly, you will receive an error message. "Wrong numbers" means you have entered a combination which does not exist in the current matrix. "They're not =" means your input does not equal the red number.

After each problem you are asked whether you wish to continue. Input N to see a scoresheet showing your results plus your estimated IQ of reasoning powers.

Programming Hints

The matrix is displayed in double height, double width characters. This is done by using Mode 5 to give double width characters and then defining 20 user defined characters which consist of the top halves of the numbers 0 to 9 and the bottom halves of the numbers 0 to 9.

The pattern for the numbers 0 to 9 is found by calling the OSWORD routine with the hexadecimal number A in the accumulator (%A). The OSWORD routine is at &FFF1. See the User Guide for further details if you are not familiar with machine code or the ROM routines.

If you wish to increase the number of rows or columns of the matrix then you must change the maximum value of I (row) or J (column) in the FOR...NEXT loops.