QL Technical Guide

This guide describes the methods which may be used for machine code programming on the QL. Its contents are also relevant to compiler writers who must implement a run-time library for other languages. This guide describes only those techniques which are specific to the QL. It does not contain a general description of 68000 or 68008 assembly language programming: this information can be obtained from a number of different sources, details of which may be found in the bibliography. It is, therefore, strongly recommended that a reference book describing 68000 assembly language be consulted before attempting to understand this guide.

This guide also gives details of how various peripherals such as hard disk interfaces, add-on memory and ROM cartridges may be added on to the QL, with many details about how the firmware for such devices should be written.

Readers may notice that there are no circuit diagrams or detailed explanations of the QL's internal hardware structure in this manual. This is because it is not necessary to have such information in order to write software for the QL. We have tried in the design of Qdos to provide you with a stable interface to the machine through its operating system; everything you need is there and so long as you build your products using the interface provided there is no danger that any future upgrade of the QL will introduce an incompatibility with existing software products. We will, in short, continue to support all of the system routines documented in this guide, but specifically reserve the right to change the QL's hardware or fireware in any other way we think fit. Provisions of circuit diagrams and the like would, apart from endangering the safety of our design patterns, be giving you a route to build products that rely on nonsupported elements in the QL's design.

The commercial section of this guide sets out the various options offered by Sinclair Research for the distribution of QL Software. Its aim is to give you an idea of the way in which we work and the likely channels through which a potential product would pass before it is accepted for publication and offered for sale to our customers. The section also gives information on the purchase and duplication of Microdrive cartridges.

195 pages, in black A5 ringbound.

Contents

1.0 About this Guide
2.0 Introduction to Qdos
3.0 Machine Code Programming on the QL
4.0 Memory Allocation
5.0 Input/Output on the QL
6.0 Qdos Device Drivers
7.0 Directory Device Drivers
8.0 Built-in Device Drivers
9.0 Interfacing to SuperBASIC
10.0 Hardware-related Programming
11.0 Adding Peripheral Cards to the QL
12.0 Non-English QLS
13.0 Manager Traps
14.0 I/O Management Traps
15.0 I/O Traps
16.0 Vectored Routines
17.0 Qdos System Standards
18.0 Qdos Keys
19.0 Doing Business with Sinclair
20.0 Bibliography

From Sinclair User 38

AT LAST it's here. The QL Technical Guide, by David Karlin and Tony Tebby, took more than a year to escape from the inner sanctum at Sinclair Research but, due to great public demand - and outrage - those guidelines have seen the light of day.

The neat A5 book, complete with hardy ring binder cover, is a pale imitation of the full QDOS specification which is available to software houses if they shout loud enough but it is certainly worth the wait, and worth its weight in gold. Not only does it cover the utilities available through QDOS but it provides blueprints of the memory map, information on system variables and all the data you need on that nefarious subject, multi-tasking.

Skimming through the 195 pages of text and index gives a good idea of the IQ rating necessary to understand most of the information in the manual. You do not have to be a genius but it does help. The technical manual is not meant for the SuperBASIC programmer. You do need some knowledge of 68000 code and general knowledge of traps and other interrupts. If you have the background the book will give you all you need to know about the internal workings of the QL.

One area that it purposely does not cover, however, is the hardware of the machine. No chip specifications are given and there is not one blueprint hidden within the volume. The authors explain that such design blueprints would be 'giving you a route to build products which rely on non-supported elements in the QL design.' In other words, you might start to use some of those hardware functions within the 68008 which are not supported by the QL.

The book is expensive but there are factors which make it an imperative buy for a machine code programmer. On the QL you should always go through QDOS. Both authors are intimately connected with Sinclair and work on the QDOS operating system. The other reason for purchasing the manual is that it does not hold information back from the reader. If there is something that you need to know about QDOS it is likely to be in the manual.

The QL Technical Guide is a great box of assorted tricks. If you want to perform magic on your QL you should buy it.