Cronosoft has recently released onto cassette tape Shapestack T1K plus Lazy Frog, both by Russell Marks and Bob Smith's Domin8tr1s for the Sinclair ZX81, with the first two games neatly running on an unexpanded machine, and the latter requiring the wobbly 16K RAM-Pack.

Taking each in order, Shapestack T1K is a simple, no-frills Tetris clone, which plays all rather smoothly once you get used to the control layout on the keyboard (which is not redefinable). Even with the memory constraints presented by the host hardware, there's still enough there to keep you occupied for a while. For those who don't know, the task is to rotate and sort the falling shapes so that they snugly fit together at the bottom of a well in order to make an unbroken row of blocks. Any gaps will cause the play area to fill, which will eventually stop more blocks from falling. At which point, it's game over.

Lazy Frog, again requiring no additional random access memory, is a Frogger-clone running in about a quarter of the full screen. Requiring a little imagination due to the pre-defined character set being used (this is again a symptom of the host hardware and memory limitations). You must guide the frog (shown as an 'X') across a busy trunk road and dangerous river to his usual breeding grounds, ad infinitum until you meet a hazard such as a car or the fast-flowing water (a bit strange for an amphibious creature!) and all lives are lost, of which you start with three.

Both titles are as much a demonstration of coding efficiency as anything else, but still very playable and worthy additions to your collections, considering that the mini binary monolith has recently passed its 30th anniversary.

Moving onto Domin8tr1s, this entertainment software product requiring a whole 16K is a mixture of dominoes and Tetris, in that in place of the rotating shapes are numbered dominoes, which must be placed to match other numbers to that value. For instance, if you have an assortment of sixes, they must be adjoined to the same numeric value six times horizontally, vertically or both. The catch is that ones cannot be removed (thus cluttering the play area) unless adjoining a legal grouping as described.

Prices are £2.99 plus postage and packing for the Shapestack T1K and Lazy Frog cassette, and £3.99 for Domin8tr1s, and both may be ordered now from www.cronosoft.co.uk.

The German-based Commodore 64 developer Jorg Heyltjes has recently released a Lady Bug clone with level designer called Lady Kakerlak.

Developed and released by Universal (www.gamefaqs.com/features/company/5822.html) in 1981, Ladybug put you in control of a Ladybird (yes, the original game hails from America) around a single-screen maze while trying to avoid nasty roamers and munching the food pellets. If that all sounds familiar to the popular Pac-Man, then it probably was in the same style, except for the fact that this game had rotating gates which were changed when the player passed through them. It is also a much more difficult game than the famous outing by the animated pizza base.

Lady Kakerlak is a solid and slightly easier version of the original arcade game, and is free to download from tinyurl.com/LadyBugC64