SpritesMind.Net

Minty, we seem to be on the same page with this serial thing. I'm going to make some orders soon and pick up what I need off of ebay most likely and put my own cable together but if you have a known working design for a cable that would be a great help.

Edit: some code could be useful too, if only ...

There should definitely be a SpritesMind wiki, there is too much valuable information on here to just let it sit on a message board. This is the best technical/homebrew 16 bit Sega board on the net. I'd even volunteer time to upkeep a wiki.

Also as far as z80 I wouldn't say it's really more difficult but I don't like it very much... I don't like little endian, I don't like the right to left destination/source syntax, I don't like having registers you can count on one hand. It's also a different kind of thinking than 68k because it's 8 ...

Yeah I don't know why I wrote it that way, that's wrong. lol. The signs go outside the brackets.

As far as stack overwriting RAM variables it could happen if your stack gets big enough but that's part of the reason the stack is traditionally at the end of RAM. You would need to both nearly fill the ...

You're right, I was thinking of just counting lines but I guess though that might work in a context of timing for linescroll graphics it doesn't actually translate well to a timer.

Isn't there some kind of problem with the 2612 timer that makes it spotty? Like something about how the timing isn't ...

I like passing on the stack the best but I develop with both assembly and C combined, where stack passing is the way to call an assembly subroutine from C.

Stuff is moved onto the stack by decrementing it, so:

move.l d0,(-sp) would be putting it on the stack and
move.l (sp+),d0 would be putting ...

Like MoD and you said there is the main 50/60 Hz vblank, and also 223 (I think at least on NTSC) hblanks, so you'd have fractionals of 1/223rds of a second. I think you could scale this up to a reasonable range of BPMs.

If you really want something simple, you might just want to get one of these .

Wiring that to the end of a male DE9 might just be the easiest thing to plug right into the unmodified port, and I like neat solutions like that. What I don't like is the cord is 18 bucks. :) Googling around suggests ...

Thank you SO much. Just a couple more questions: Does 3.3V TTL or 5V matter? From what I can tell the MAX3232 breakout boards put out 3.3V so I'm curious as to whether I can get away with that or if I need an actual MAX232 part. I'm assuming the genesis is probably 5V, so what I'm really asking is ...

Also, thank you for your GEMS tools. The splitter, combiner and instrument converters are very helpful

I have a model 1 with the EXT connector I'd like to use for serial communication via RS232--simple text, maybe xmodem for very small transfers. I want to hook it up to a PC serial port. My machine doesn't have a parallel port (so, not an option for now), and I'm on Linux. I have looked around this ...

If you can read C the SGDK source is excellent documentation!

_gemsholdz80 - is just busreq.
if you hold it somewhere (in main for example), and then interupt occured, and if it contains another hold call, it will deadlock, because you can't hold bus TWICE.

I think this is what happened because refactoring my code eliminated the problem. Now that I am aware ...

Also you'll want Charles MacDonald's VDP doc and the info on this page and maybe the interactive VDP docs at the bottom of that page.

Actually for programming of this sort you'd probably be fine with basic algebra. Mostly you're going to want a good understanding of the chip hardware and FM synthesis in general, but the advantage of programming to hardware like this is it's not the same as programming something like an emulator ...