Grundy NewBrain - Software

Software

The unexpanded NewBrain contains software provided in ROM, primarily BASIC, a full screen editor and device drivers. Other packages were also included within the ROM (e.g. maths and graphics packages) and were accessible to BASIC and any other software.

All I/O was stream-based, and orthogonal: any device could be replaced by an alternative, although the manual did warn that devices had to be chosen with care. This approach did make it easy to write programs that could swap between input and output coming from a screen, keyboard or a tape.

The maths package had 12 figures of accuracy and a dynamic range of 10−150 to 10150, compared to most common machines having 6 figure accuracy and a dynamic range of 10−38 to 10+38. This was achieved by using base 256 for the floating point format, rather than the more common base 2, and using 6 bytes for storing numbers, rather than the more common four. Five bytes stored the basic number, with the last byte storing the sign in the first bit, and the remaining seven bits storing the exponent. For example, π was stored as 3.14159265358.

Benchmarks show that even though the NewBrain performed double accuracy calculations, it was one of the fastest 8-bit computers available for several years, completing PCW Benchmark 8 in 7.0 seconds. For comparison against other contemporary machines, the Sinclair Spectrum took 25.3 seconds, the BBC Micro took 5.1 seconds, but with fewer significant digits. The 16-bit IBM PC took 3.5 seconds.

The graphics screen was separate to the text screen, and was opened as a new output stream that shared space with the text screen. The graphics commands were based on 'turtle' keywords and provided a flexible means of drawing. The last two generations of NewBrain ROMs included additional graphics commands — ROM 1.9 had two more commands, and ROM 2.0 some more. But to ensure compatibility little software would use these additional commands. The programmers were working on version 2.2 as well as versions for different keyboards, including Greek and Swedish as well as French and German. Grundy had been considered offering the Series 2 ROMs to existing users. This required the existing soldered in ROMs to be removed from the circuit board and a socket soldered in. The tight fit and labour cost was high on this retrofitting, and the failure of the company in 1983 meant that users were never aware that this was being considered.

The version of BASIC was an extended version of ANSI BASIC, the facilities of which were similar to those in Microsoft BASIC. The graphics package included commands that could draw dots, lines, arcs, filled-in areas and annotated axes.

Grundy offered a 'Software Technical Manual'. This manual documented various routines that could be called in the ROM and the calling parameters. It was left to the NewBrain user groups to publish the details of how to access these routines through the indirect call (a low-memory address was called with the relevant routine parameters, and this address would call the ROM-specific location of a jump table which, in turn, then called the final routine.) Even screen access required this indirect use, as the screen location would change as new input and output streams were created, including high-resolution (for the time) graphic streams. Memory maps and other technical information were included in numerous technical notes which were supplied to dealers and owners free of charge. The Technical Manual had a retail price of £50.

HiSoft produced NewBrain versions of their Pascal compiler and editor. A number of CP/M applications were converted to using the NewBrain's CP/M terminal and made available on NewBrain 5.25" and 3.5" formatted diskettes. These included Z80 Assemblers and debuggers, Pro Pascal and Pro Fortran, TCL Pascal, dBase II, Wordstar 3.3, Peachtree Accounting applications, the Superfile database and CP/M versions of Hisoft Pascal, Modula-2, Z80 Assembler and text editor.

Many third party software houses (e.g. IEL, MicroMart, Black Knight Computers) provided independent software for the NewBrain, which was supplied to users such as the British Ministry of Defence, and Cambridge University.