80-Bus News

To put before you I have six books on CP/M. These are:

Osborne CP/M Users Guide by Hogan, (286p) publ. Osborne/​McGraw Hill
CP/M Revealed by Dennon, (180p) publ. Hayden (dist. Wiley)
Mastering CP/M by Miller, (c300p) publ. Sybex
A Programmers Notebook:Utilities for CP/M by Cortesi, (368p) publ. Reston (USA), dist. Prentice Hall
Inside CP/M – A guide for users and programmers by Cortesi, (571p) publ. Holt. Rinehart Winston (USA) dist. Holt Saunders
System Programming under CP/M-80 by Hughes, (197p) publ. Reston (USA), dist. Prentice Hall

If you cannot (or will not) read 8080 mnemonics, then stop here. All these books admit to the existance of the Z80, but are written in 8080 mnemonics. These are nearly impenetrable – I find I can visually disassemble hex listings easier than understand these. Due to an accident of history, the 8080 type mnemonic has dominated the USA – very much to the detriment of the code produced. As the first reasonably priced and popular processor in the UK was the Nascom, it set a firm base for Z80 mnemonics. Oh for a book on CP/M using Z80 mnemonics!

As in all of the Osborne manuals, the Osborne CP/M User Guide gives a clear, competent discussion of its subject. It surveys all of the standard utilities supplied with CP/M, effectively being a rewrite of the supplied D.R. manual. It includes a full index.

CP/M Revealed is a ‘hands on’ exploration guide to this operating system, using the standard utilities. By means of demonstration programs, the author shows how to explore the visible and invisible portions of CP/M. He develops an interesting utility named COMMON to allow read-only access to files across USER partitions, and another to Restore an erased file.

In 80-BUS News V2 No2, Dr. Dark reviewed Miller’s Mastering CP/M. Firstly let me ask “How dare Dr. Dark attempt to review a book?” I was incensed when I noticed his review in 80-BUS News V2 No2. Then I forgave him. After all, the poor chap must need to resort to almost any method to bolster his ego – and a discriminating, educated, discerning audience such as yourselves would not easily be fooled by the disjointed scribblings from his pen! For the experienced programmer, this is probably the best purchase, introducing as it does the concept of the Macro Library, and the use of the Macro Assembler. It is worth remarking at this point that the Microsoft Macro 80/​Link 80 package differs in many small ways from D.R.’s MAC. The major difference is that the Macro 80 can understand both 8080 and Z80 mnemonics if one sets the right switches, whereas DR’s assembler only handles the Z80 instruction mnemonics by means of macros.

A similar book is A Programmers Notebook by Cortesi. This sets out to introduce the experienced programmer to the use of the Macro Assembler, again using DR’s MAC, to explore the facilities offered by CP/M. He constructs a series of programs to extend the standard DUMP utility, to PACK and UNPACK ASCII files, which can save a lot of space on a disc of text, Include to allow almost any program to include other files on disc as if they were typed into the file in full, and a MACREF, a cross refernce generator. I am unable to compare this with Miller as my copy of Miller has been on loan for the last few months. Try and see both of these books before making up your mind. My impression is that Cortesi’s programs are more substantial than Miller’s, but that Miller is more generally useful.