Pick of the pac

Space and maze madness on the ZX-81

ONE OF the major disadvantages of the ZX-81 is that the graphics, if you can call them that, are very low in resolution, being made up of black blocks which can be PRINTed or POKEd on to the screen.

Computer Rentals Ltd has circumvented the problem by producing a 16K high-resolution package which will give a screen display on a grid of 192 x 256 pixels. It can be POKEd into action from a Basic program.

All the usual Spectrum graphics are available, in black-and-white format, including circles, line and arcs, It is also possible to make your own user-defined graphics of objects such as space invaders, pac-men, or even foreign alphabets.

Although the utility can produce some incredible pictures, there are disadvantages. If you intend to draw complex designs using mathematical formulae which include sine and cosine, you will find that the computer takes about 20 minutes to complete the graphics in FAST mode. You will have to tolerate the grey screen for a considerable time. It does not take quite so long to draw a few lines and circles but it certainly takes longer than its big brother, the Spectrum.

One of the major shortcomings of the package is the pocket-sized manual which attempts to explain all the features of the utility in a short space. The booklet seems to have been written by a programmer, or by a person who has taken for granted that the user will know about the computer and its memory map. Such an assumption is dangerous and leaves new users rushing for books on machine code or, at least, a book on POKEing.

High-Resolution Graphics can be obtained from most branches of John Menzies and W H Smith.

Although Quicksilva is not producing new ZX-81 arcade games, the company still has some top-ranking games in its range. Galaxians and Gloops are two games on one cassette, one of them an old arcade favourite and the other an old favourite under a new name.

Galaxians involves a flock of alien birds which take turns to swoop down the screen at your laser base and fire death-dealing energy bolts.

The screen display is not so awe-inspiring as other versions of the game. For instance, the birds do not swoop with wings at an angle - they just drop down, like Vs, from their positions in the flock.

The game is difficult to play, even though you can alter the way in which the aliens attack. It is possible to change the number of Galaxians which swoop at you and also the number of aliens. You can also change the number of salvos which are fired at you.

Even at the lowest settings the game can become irritatingly difficult and addictive. At the highest level only the best arcade player will survive for any length of time.

The other game on the cassette is Gloops. It is difficult to know why Quicksilva decided to use that name but the program is an average version of Pac-man.

The only differences between Gloops and the original Pac-man is that the maze layout can be changed by the player and the speed of the ghosts can also be set. Unfortunately the instructions are vague as to the scale at which the speed is set, so if you type zero the ghosts will react quickly and if you type nine the ghosts will be slow.

Gloops is one of the fastest versions of Pac-man on the ZX-81, even if it is not the best graphically. It can be obtained from Quicksilva or from W H Smith.

Another Quicksilva double-game cassette is Damper and Glooper, both for the 16K machine.

Damper is a game in which you take the part of a droid who must turn off the power on a grid before the leeches damage the power cables. Your character travels round the power lines and when you have been around the square, that square is filled and the power will be turned off. To reach the next level you must turn off the power in all the squares.

By chasing round the squares you can attack the leeches. If, on the other hand, you are touched by one of them they will electrocute you and a life will be lost.

The game does not need high-resolution graphics to be effective as it uses thick lines on the screen. The special effects when your damper is electrocuted give the game a professional finish.

Glooper is another version of Pac-man which looks like a car, and the ghosts, which look like little racing cars, chase after it.

As usual, the aim is to evade the ghosts and eat the power pills. Glooper is more innovative and attractive as a version of Pac-man than Gloops. It uses the whole screen to display the maze, rather than just a portion in the middle. The two games look sufficiently different from each other to justify a company putting both in its range but the concepts are too close for comfort.

All Quicksilva ZX-81 games are worth buying, although they lack features which would have been helpful. For instance, it might have been a good idea to put in an option to re-define what can be used during play on all the games. If that had been the case the games would have been easier to play, by left- and right-handed people, and also much more user-friendly.

Sinclair User
July 1984