MCODEing on OSX

[Monte Dalrymple]

(04-07-2019 06:41 PM)hth Wrote:  One of the amazing things about MCODE is when you start your project and "create" a new 4K page, that tiny canvas, there is so much functionality that can be squeezed into it. I have seldom met anything quite like it.

This community is just too small for anything to really happen. We are also quite diverse on how we work, the things that do get done. This is a matter of personal taste I suppose.

We have different instruction sets, different ways of entering code and are far apart from agreeing on anything that is even resembles something similar. With git and hosting, it is possible to create public projects, download, build and collaborate. However, we are just too few people spread out that do things differently, it is just impossible.

Apart from instruction sets and ways to enter code, we even have a limited system address space. I have a great idea (I believe, and I already started a bit on it) to make a generic system extensions module. The main problem is that it requires page 4 and Angel has already claimed it. It would need access to those cold start vectors to pull it off, but that is not possible now. Yes, I suppose I could do it anyway, but who would use it? If I make a couple of modules, what is that going to be against the 20 popular modules Angel makes. So even if I did make it, there will just be me using it in the end.

I think there is no point with a Slack channel, there is too little is happening. I can always use the forum as my rambling area instead, if I find some time at some point and feel like it.

Now I head back to my other projects.

If you are writing something for the CL, the MMU makes it possible to dynamically load stuff into Page 4. You don't have to move anything because only the MMU entry for Page 4 changes. This is the technique I use with the 41CL Extreme Functions (YFNX), which makes extensive use of the 4LIB image. I do the same thing when I am dealing with Flash, although in this case I do have to move sections of code into RAM before reprogramming the MMU. I then jump into Page 4 (executing out of RAM) while I do the Flash erase/write stuff.

If your Page 4 System Extensions are called by functions I would recommend using this approach. The sources for YFNX and YLIB are on the 41CL website. The one complication doing this is error handling. You can't just display an error and exit, because you always have to undo the MMU remapping. Again, YFNX and YLIB show how I do this.

I use dedicated code in the module to do the dynamic paging, but if your CL is up-to-date the same code is available as a subroutine in Page 3.

I agree that doing MCODE is extremely rewarding and it is amazing what can be done in 4K. I also love going through the HP listings looking for tricks and the inevitable "why didn't I think of that" moments.

Monte