Using this package is considerably more difficult then using Basic. With a
number of fairly minor improvements and with more comprehensive documentation this
would become an impressive product.
Source and Price
______, _ _________ ____, Sheffield __ ___. Tel: ____ – ______
Price 35.00 + VAT
a software review by Richard Beal
MAPP 1-4Z is a 4K floating point arithmetic and functions package for the Z80
processor. It is completely independent of the specific computer or operating system
under which it is run. It is also written in position independent code so that it can
be moved to and then run in any convenient location in memory.
The package was provided on tape in Nascom 1 format, and the demonstration
program provided at the front of MAPP 1-4Z had been written for the T4 monitor, but we
read it into a Nascom 2 using NAS-SYS ( and a special hardware interface) without
difficulty. The demonstration programs worked at first attempt, and during testing of
MAPP 1-4Z, no bugs or faults of any kind were detected. This is high quality software.
MAPP is used by coding an ordinary call to the start of it, which is followed
by one or more MAPP instructions. The last of these is EDH which returns control to
the ordinary Z80 instruction following. In effect MAPP provides an additional set of
instructions for the processor. These instructions treat the Z80 registers in
combination providing two 40 bit floating point registers. The effective accuracy is 8
significant digits. While this is better than Basic, it is far short of the
conventional “double precision” which has 15 or 16 significant digits. Perhaps a MAPP
2 product could offer this feature.
The real point of MAPP is that you can add its 4K of code to any other program
that you develop (normally in assembler), and give yourself good arthimetic capability
without the need to write and test your own routines.
It would also be easy to write a demonstration program using MAPP to provide
simple calculator capabilities.
|12||arithmetic instructions (eg: square root, divide, etc)|
| 9||transendental functions (eg: sine, log, etc)|
|12||operational instructions (eg: push/pop, relative jump, etc)|
|10||data transfer and ASCII conversion instructions (eg: output ASCII in user
selected format, etc)|
| 1||delay instruction|
MAPP also allows for an extended form of call which includes error handling,
so that errors in the MAPP instructions can be handled by your program.
The documentation is excellent and is printed and bound. Updates to MAPP are
supplied through distribution to registered users by the supplier.
MAPP was written by John Turton of the University of Sussex, and is supplied
Enertech Ltd., __, _________ ____, Eastbourne, East Sussex ____ ___.