Individual RSX commands are published regularly in Popular Computing Weekly, but it is often very difficult to merge them together into one machine code program to use in your own programs. This program allows you to do just that. It allows the user to create a database of RSX's from which any number of commands can be selected to create a customised Basic extension package. To store the data it uses an extra 16K bank of Ram, thus making it compatible only with the CPC 6128 or an expanded 464/664. This is a very complex program which will probably only be of use to people with a knowledge of machine code. An RSX command can be separated into two parts: the RSX table and the actual machine code program. This machine code section must be relocatable, or else it connot be placed into the database. The database ignores the RSX table. The user must make a note of the memory address and the length of the machine code section (not the RSX table) before loading a file into the database. Menu options When the program is run, a menu containing nine options is displayed. To select an option use the up and down cursor keys and the Copy key. Of these options Disc/ Tape Catalogue and Exit program are self-explanatory. There now follows an explanation of the other options. The Load Machine Code Data option allows the user to load in a file containing one or more RSX commands. The file is loaded to the address specified by its header. Files should not be loaded in below
address 13000. You do not have to worry about load files sequentially. Once an RSX routine has been stored (using the following option) you can forget about the original code. Once a file is in memory RSX's can be “plucked” from it using the Store RSX Routine option. To place an RSX into the database the user must specify the name of the RSX (this need not be the same name as the original RSX), and the address and length of its machine code section. Ordinary machine code programs can also be transformed into RSX's with this option. The database can hold up to 16K of machine code routines. Once an RSX has been entered into the database a hex dump of it can be displayed using the Hex Dump or RSX Routine option.
This two part listing is available on tape (£3) or disc (£5.50) from 41 Fountains Drive, Acklam, Middlesbrough, Cleveland ****. PCW
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