J: The Programs Disc

The program disc has been specialy put together to complement the 512 Technical Guide, while at the same time helping you make the most of your 512. Its contents include:

Demonstration Software

Demonstrations of many of the third party programs detailed in appendix H are included on the disc for you to run in your own 512. All the programs provided are functional and can be tested in your own applications in the way you choose.

512 BBC BASIC

This is one of the many programs Acorn should have supplied with the 512+ Written by Richard Russell, author of the BBC BASIC which Acorn did supply with the Z80, it is a very dose emulation of the BBC rnicro's inbujit BASIC, but it runs in the 512 under DOS Plus.

The commercial PC version of this package would cost you 100.00, but this special 512 version which is freeware (provided that you know where to get it!) gives facilities much closer to those of a real BBC micro. It suffers far fewer of the limitations normally imposed by DOS in PCs because some of the BBCs native facilities can be used. One not available in the PC version of the package, for example, is true BBC screen displays. Two versions of the program are includel, a more efficient small version for programs of 64K or less, while a large memory version permits programs of a size you could only dream of in the RISC micro, even with a 6502 second processor.

The package contains dozens of ready written examples and demonstrations to ensme that you can have your first BBCBASIC program running within moments of loading the language.

A commercial version of the Z80 version of BBC BASIC which includes a 500+ page manual is available from M-Tec Computer Services, telephone 0603 - 870620.

A86/D86

Normally available in shareware (at almost the cost of this disc on its own) A86/D86 is the assembler & debugger for the 86 series of Intel microprocessors. It is so well written that it is 100% compatible with the 512. Supplied in archived format to conserve disc space, this package provides the complete range of tools needed to produce professional quality software for the 312.

The package includes extensive documentation on the disc which, together with the introduction to the 80186 and the interrupt call information in this book and the example programs provided, should allow anyone to begin to explore 80186 assembler programs in a short time. The assembler is particularly easy to use, being unusually flexible in its requirements for source code layout and organisation. The debugger allows programs to be single stepped, with the ability to display several different areas of the 512's memory, while at the sarne time continuously showing all the 80186 registers' contents.

Example Programs

The 512's version of DOS Plus officially claims only compatibility for DOS interrupts 20h to 27h, but in fact many others an implemented, some to quite surprising degrees of completeness. Source code programs ready for immediate assembly by A86 are provided to show how 80186 assembler code programs are constructed. In addition they demonstrate many of the functions which you will most frequently need to use in your own programs.

Examples of the general function despatcher (INT 21h) include string and character input and ontput, disc file handling, the highly efficient techniques available for comparing areas of memory (e.g. text strings) as well as examples of the ROM BIOS calls (INT 10h) which an needed if you wish to control screen effects such as inverse and bold, the cursor position and formatted output to the screen.