Initially the computer was only available by mail order,[2] and Jupiter Cantab reported that there were production difficulties, but these had been overcome by January 1983 and that units were arriving in shops.

[7] The use of Forth rather than the more usual choice of BASIC, and the availability and success of the ZX Spectrum, as well as limited published software, the poor case and small initial memory all weighed against wider market acceptance.

[8] The brand was then acquired by Boldfield Computing Ltd in 1984 that sold the remaining stock by mail order for £26.

[9] Sales of the machine were never very large; the reported number of Aces sold before Jupiter Cantab closed for business was around 5,000.

A 1982 review stated that "The success of the Jupiter Ace will depend on the machine-buying public's acceptance of another microcomputer language.

[3] Attempts to promote the Ace in the educational market also failed; doubts over whether Forth would be relevant for exam syllabuses, and the lack of support for Forth from teaching staff were key issues.

[11] Pupils were more interested in learning the widely used BASIC than a language used by only one (uncommon) machine with a peculiar RPN syntax.

Similarly, a television was needed as a display – but this was in black and white only, rather than the colour supported by competing models such as the Spectrum.

The Jupiter Ace was based on the Zilog Z80, which the designers had previous experience of from working on the Sinclair ZX81 and ZX Spectrum.

The remaining 3 KB of ROM supported several functionalities: floating-point numbers library and character definitions table, tape recorder access, decompiling and redefining newly re-edited 'words' (i.e.

Using the higher-address would briefly pause the CPU on the interference, affecting the program timing and making this mode unsuitable for I/O operations.

The other 1K bank stored the full screen display of 24 rows × 32 columns of characters in black and white.

A PCB was also marketed by Boldfield Computing that converted the edge connector to electrical compatibility with a Sinclair ZX81, allowing use of the ZX81 16K RAM pack.

References to the Ace RAM sometimes include the separate 2 KB video memory, which was not available for programming, thus leading to some confusion.

Threaded compilation allowed programs written to run nearly as fast as many native-compiled languages loaded by more expensive computers.

[6]: 171 Its Forth was adapted to the disk-less tape-using home computer hardware by being able to save/load user "compiled vocabularies", instead of the usual numbered programming blocks used by diskette systems.

To allow decompile, it distinguished usual Forth definer and compiler words creation, replacing the CREATE .. DOES>,[24] creation pair with: These two defining pairs, instead of one alone, allowed the Ace to decompile its programs, unlike usual Forth systems.

Not storing the source of a Forth program, but compiling the code after editing, it avoided completely the emulation of a disk/tape drive on RAM saving computer memory.