[Coco] Assembly and RS-DOS disk access

[Allen Huffman]

I recall two types of disk access that assembly language programs used:

1. Using ROM calls. These programs were more likely to work with alternate DOSes such as RGB-DOS for hard drives.

2. Direct assembly. I recall some 64K word processors and such that did their own, so they did NOT work on things like RGB-DOS.

My question is:

How did either of these programs do the disk access? “I seem to recall” that the ROM routine DSKCON only was the basic read or write sector stuff (and maybe format or something too? Looks like four codes it accepted).

Doe this mean programs either had to cheat and use undocumented ROM calls, or implement the RS-DOS disk structure themselves?

I also “seem to recall” that Disk EDTASM+ came with “Color TRS-DOS” which, I believe, was a loadable set of routines to handle Disk I/O. But I never did anything like that, so I never looked at it.

What do you recall?

		- A