NST's Monitor Extension

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A little history, or the humble beginnings:

The foundations of this expansion was written by Csory around 1992. It was a program to be burned into ROM, to be used in an external (possibly the 2nd) bank. It extended the stock machine's function in several areas. It even had a BASIC extension, which included the following features:

These were pretty good features, but they weren't used (much). In addition, it included a "turbo" section:

These are functions that are (partially) still used, but apparently it was geared towards the 1551. (Relatively few plus/4 owners had 1551 drives, despite the fact that the drive was designed specifically for this machine family.)

In addition there were some functions that were accessible during power-up or after reset by holding a key:

But the most important part was the extension/improvement of the built-in TEDMON, the monitor program of the plus/4. Quite a number of features were included, such as scrolling lists, basic disk support, drive memory management, etc. (It also contained an unfinished debugger, but you could really see that it was alpha quality.)

This program (was only minimal changes) was not in use for long, because a few requests came up could not be done by patching the binary code. (One of the first of those patches was for the memory wipe function, changing it from the Control key to key combinations.) This could only be done by getting the source code (from disassembling the binary), since the original source was not available. (This was done on a plus/4, as at that time there weren't any cross-platform tools!) After that, the new source code could be changed and new features could be added. The resulting "improved" program was in use for many years, until around the early 2000s when once again more changes were needed. By this time, development was done on the PC via cross-platform development, so that the source code has been moved there. The result of the many, many changes was a highly over-complicated code base, and some problems emerged that were impossible to solve. Instead of debugging it, the code was re-written multiple times (which is why the version number is 7), so the current version contains very few traces of the original code. (Nevertheless, much thanks to the original authors!) Of course the insertion logic remaind, as well as the names of most features, but it was supplemented with a few new features, and some things (which were not needed) were removed.

The current status:

The extension does not include a BASIC extension, there's no use for it so it won't be added. The "turbo" part is currently missing, but the original (being 1551 centered) wasn't that useful anyway. The plans include a framework that will be the basis for a loader that would work with multiple drives, but that's still in the future.

What is currently useable:

The extension of the original TEDMON (instead of a completely new monitor) is good because the proven old (mostly programmers') habits will continue to work. Among the MONITOR's commands are several that are written specifically for the drive's memory, the original TEDMON provides no such options. Reading the various ROM configurations wasn't solved eithe, but this is not a problem anymore. The memory management functions are using a separate buffer, so some commands will be performed faster than with the original TEDMON. (Typically, these are the Fill (F) and the Transfer (T)). Most of the command names remain a single character, but there are are several commands with longer names. The built-in HELP command will be useful to get around, but there's also documentation available to help development.

WARNING: USE AT YOUR OWN RISK! THERE IS NO WARRANTY OF ANY KIND! (But any bug reports are always welcome.)

The name of the current program is made up as follows:
BMX-x.yz-b-abcd-yymmdd – (Example: BMX-7.02-A-0123-140119) This includes the following information:

The required files are:

Older versions:

Translated by Csabo /