Whoosh! Who would have believed this? Manic Miner for the good old ZX81? And it's great too! Eleven screens of hi-res graphics! One of the best games ever for this lovable little computer! The very rare Hi Res ZX81 version of Manic Miner was possible because the ZX81 display was generated primarily by software in the ZX81 ROM, it was possible to override the interrupt service routine and generate the display oneself. Several "hi-res" (meaning, 256×192, rather than 64×48) games exist on this computer, but came out too late to save it from its big brother, the ZX Spectrum.
Considering the limitations of the machine, this game is a minor miracle!
As with the ZX80, the processor was a NEC Zilog Z80-compatible, running at a clock rate of 3.25 MHz, but the system ROM had grown to 8192 bytes in size, and the BASIC now supported floating point arithmetic. It was an adaptation of the ZX80 ROM by Steve Vickers on contract from Nine Tiles Ltd, the authors of Sinclair BASIC. The new ROM also worked in the ZX80 and Sinclair offered it as an upgrade for the older ZX80 for a while.
The base system as supplied had 1 KB (KB) of RAM. This RAM was used to hold the computer's system variables, the screen image, and any programs and data. The screen was text only, 32 characters wide by 24 high. Blocky graphics with a resolution of 64 by 48 pixels were possible by the use of the PLOT command, which selected among a set of 16 graphics characters. The ZX81 uses a resizeable display-file (screen buffer) meaning that it can be expanded or shrunk depending on the amount of installed memory and the amount of free space at the moment.
The ZX81 was originally sold via mail order in kit form requiring soldering (priced at £49.95) or assembled (£69.95 or US$100 in the US). A later deal with high street retail W.H.Smith saw the ZX81 and all accessories being sold on the high street (ZX81 was £69.99, ZX 16K RAM pack £49.99, ZX Printer £49.99)
This game plays extremely well and is available to download from my website, www.mjscomputers.net/arcade2.html
13 сен 2009
