6502.org

I may allow linkage to be separated out. Presently, all assembly is done in "stages" each stage is a singleton, but expects the input to be from the previous stage, meaning some stages might crash if given input that has not been run through the prior stages first. Although the way that I'm doing it is not really the *most* optimal way, the nice thing is it is almost entirely static with (O)n being the complexity for each stage except macro parsing, which is (O)n*deepestMacro for nested macros. Certain other stages are a little bit over (O)n but they're all at most logarithmic, not exponential.

I will say, I think the main thing my assembler has to offer is simplicity. I'm using it for all my programs simply because it's easier to use than others. I plan on getting this up to the level of others, but allowing for simpler programs to be assembled easily without the need for makefiles or complex setup. Presently, it goes from code in to written EEPROM in about 20 seconds, with about 19.5 seconds of that being writing the eeprom one byte at a time (haven't setup my arduino to accept multiple bytes at once) This is with only 3 includes, and each file that's included is not very big (system vars that lays out EQUates for addresses of different devices, number converter that can convert binary data to ascii decimal data, and the display driver, which I just modified to use less macros (and hopefully save some code space) that controls writing strings to the display.)

I think that the next feature I'll work on is DP relocation support, so it won't crash if you try and do that (since it currently uses <255 for detecting DP usage). I think that, for macro and var detection on included files, adding a feature to avoid clashing would probably be useless, since it could break intended references to other files.

Definitely a long way to go before this assembler can hold any weight against others, but I'm pretty happy with the progress.

Not exactly a feature request, but it would be great if a project like this could be
- open source
- portable
- usable by command line or in a makefile

Garth's point (methinks) is that if you have to "include 'file.h'", why not simply "include 'file.s'" and skip the linkage phase.

It's a valid point.

My assembler (which does not currently support include) assembles Fig Forth at about 1000 lines/s, so it's 4s to assemble it.

I think it all depends on the complexity. One of the benefits of using object files and separate assembly is information hiding. Only public labels are public, no worries about name space conflicts across modules, etc.

The other benefit of object files is late binding on memory. Simply, you can put all of the code together and all of the data together, vs having them intermixed in the image. You can assign memory locations at link time, rather than assembly time. Thus you could locate, for example, "strcpy" wherever you like without the location be coded within the strcpy routine.

The simpler the program, the less necessary this kind of thing is. With flexibility comes complexity and build performance.

I think it's really much more important on a large '816 program that uses a large code space.

Time isn't the issue on a modern system. My desktop - a somewhat modest intel i3 system running Devuan Linux assembles & links one file in the same time as all the files in my current project. It's in the millisecond region.

After a make clean:
For me, it's the way I've always done it - right back since 1980 when I was introduced to the university pdp11 Unix system. Then it was a necessity for anything non-trivial.

Typically, I start a project by writing code, then when I feel that file has grown, and has started to have a few subroutines/functions, I split it off into what I feel are manageable sections, then edit them, as needed, grow, split, and so on. It's not about speed, it's all about management. Makefiles are easy for me, (because I've been using them forever) as is cross-referencing files, labels, etc. using the tools I have to-hand. My biggest personal project is currently my BASIC interpreter - that's 130 files (about half source and header files) totalling about 30K lines.

Part of my longer term goal though is to make my system self-hosting, so to that end I'll be writing various utilities for it and that's when separate compilation/assembly and common libraries will help time-wise as there is simply no way that my little 6502 system, even running at 16Mhz can possibly compete with my desktop, so doing stuff in smaller chunks makes sense there (like right back to the old Unix days)
This is why I re-wrote sweet16 - For space efficiency, Woz gave it a built-in dependency on where it sits in memory. I wanted to remove that. The computer (assembler/linker) ought to have a far better idea of where to place things them me sitting down, counting bytes and working it out... (at least I hope so!)
Highly likely - but who is writing large programs right now (02 or 816?) People doing the Foenix or Commander X64 projects probably, although I've no idea what they'll be using. I'll be using my own system to write/port my BASIC into it though - the best test of it that I can think of.

-Gordon

Great goal, and a good reason to be thinking in terms of modules/libraries/linkers.

I definitely want to support make files in the future, but I also want to allow the use of the program on its own to do start to finish compilation of a set of files to assembled binary. Presently, I'm not even respecting file extensions really, just leaving things .txt and editing them with notepad++. I guess I hadn't really thought of finding an IDE for this, but I probably should, any good ones out there that support 02 or 816 assembly? Once I get into that, I'll start respecting .s and .h files respectively, rather than just lumping everything together as text.