Forth they went,
The designers of Britain's latest microcomputer have chosen the Forth programming language in a bid to gain advantage in the crowding micro market. They claim its principles are so simple that newcomers to computing need only a few minutes to learn how to calculate, and at the same time, it is easy to invent extensions to the language. The two originators of the Jupiter Ace computer, Steven Vickers and Richard Altwasser (see caption), both discovered Forth at the same time (they read the same issue of Byte) and immediately recognised it, they say, as the ideal language for microcomputers.
Forth is fast and easier to write in as well as more compact in memory because it is
Wireless World October 1982, page 75
"Leading computer designers with a reputation for pushing technology forwards" is how Altwasser and Vickers describe
themselves in their promotional copy for their new computer. Vickers, left, who previously had joined a
software consultancy near Cambridge with a doctorate in algebra, adaptated the 4K ZX80 ROM into an 8K for the ZX81.
He wrote the manual for the ZX81 as well as most of the Spectrum ROM. Altwasser, an engineering graduate, worked on the
application of microprocessors in automation before joining Sinclair. He was soon made responsible for computer research
which included the hardware development of the Spectrum. "It's about time someone got away from Basic" says Vickers.
Developed in 1965, it was then a lot easier to use than Fortran. "But it is hardly the language of the future; our
money is on Forth".
compiled, yet its compiled code is accessible to the user in the simplest way possible, say Jupiter. One gives each compiled routine a name, a Forth word, and to run it just type in the word.
Stringing old words together can define new words, which process lies at the root of Forth's power and enables one to define an infinite variety of one's own words from the standard words provided in the firmware.
Older languages make assumptions a-
bout how they will be used that inevitably lead to a straight-jacket for the programmer; Forth is not based on any such assumptions they argue and allows the programmer "to do absolutely anything". If one doesn't have exactly the instruction needed in Forth, it is simply invented.
Forth usually relies on disc-based virtual memory for editing the source program but the designers say unique editing facilities operating on the com-
First shown at last month's Personal Computer Show at London's Barbican Centre, this £90 mail-order computer features full-size keyboard, user-defined high resolution graphics, programmable sound generator, upper and lower-case ascii characters, 24x32 flicker-free display, 1500baud cassette interface, and the Forth language. Jupiter Cantab are at 22 Foxhollow, Bar Hill, Cambridge, tel 0954 80437.
piled word definitions mean that words can be defined, listed, debugged, edited and redefined without using any external storage. This they say makes Forth even easier to use on the Ace than on other implementations.
The memory saving coded form used to store programs allows it to work much faster than it would do in another language the company say - typically in less than a tenth of the time, which makes it ideal for games. Capacity is 8Kbytes of ROM and 3K of ram but because of the language it is more effective than, say, the 1K memory of the ZX81. Expansion to 16K (costing £35) should be available by the year end, as well as a printer interface board (costing £25), and later next year a colour board. By then, the company hope to be selling 3000 units a month.