Sinclair ZX81 FORTH ROM Interruptgsteuertes Multitasking-Forth Betriebssystem der 'Skywave Software' für den Sinclair ZX81, das diesen Zwerg zu einem ernsthaft einsetzbaren Rechner zur Gerätesteuerung, für die Meßtechnik und allgemein zur periodischen Kontrolle, Steuerung, Überwachung rechner-kontrollierbarer Vorgänge macht. [WoS] Skywave FORTH FORTH on ROM complete with a RS232 and Parallel interface. Year 1983 Manufacturer Skywave Software (UK) Original price £49.95 Sinclair User: THE MINISTRY of Defence, universities, hospitals and industry have discovered the potential of the ZX-81. With a little help from David Husband of Skywave Software, the ZX-81 has been adapted to multi-tasking by adding a ROM which changes the language from Basic to Forth. The ZX-81 thus becomes a powerful industrial controller, capable of running more than 10 tasks simultaneously. Working from his home at Poole, Husband has built a large turnover which he expects to exceed £1 million in 1984. More than half his customers are companies and organisations and the medical profession has been specially interested. The ZX-81 Forth ROM costs £25 plus VAT and is available from Skywave Software.