Search found 18 matches

by colonthree
Wed Apr 20, 2011 12:31 am
Forum: Regen
Topic: Regen 0.972 and 0.972D
Replies: 193
Views: 57444

Probably isn't worth making a new thread for: I'm just wondering if the image display is meant to go grey when you go into either of the CPU debuggers or ROM editor. Is this the expected behaviour for the current version? Additionally program sometimes terminates when clicking OK in the 68k debugger...
by colonthree
Sat Apr 02, 2011 9:16 pm
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

Ah right, I know next to nothing about the hardware behind the code.
Thanks again

Stay tuned for my next stupid question! :D
by colonthree
Sat Apr 02, 2011 8:48 pm
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

Controller cannot generate interrupts as the interrupt generating capable pin goes to controller not comes from controller. I see, so my next question is why is this!? Would it not have been relatively easy and sensible for Sega to implement this? Is there any use for it the way it's configured? Th...
by colonthree
Sat Apr 02, 2011 8:20 pm
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

I'm not sure if that answers my question - does a standard controller cause interrupts to happen? To get an interrupt happen from controller port you need to enable it and have something pull the TH line low from controller side. What I mean is does this^ actually happen or not? Only with special pe...
by colonthree
Sat Apr 02, 2011 1:32 am
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

Having on and off progress with this project which explains why I'm only asking this question now: Do the controllers not perform external/peripheral interrupts? From all the code/document reading I've done I don't think I've read about it being possible, it seems like you have to manually poll regu...
by colonthree
Thu Mar 24, 2011 11:56 am
Forum: Sound
Topic: Simple 4-channel sample player
Replies: 45
Views: 32901

Old thread I know sorry, but do these files still exist so I can try learn from them? (all rs/mf links in thread seem dead)

Thanks :)
by colonthree
Tue Mar 08, 2011 1:10 pm
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

The official doc clearly states CD5 must be set to trigger DMA operations. The page you read is for normal read/Write operations, read a few pages after for DMA. In a sense, it's a little bit logical, how would VDP make the difference from normal write/read operations otherwise ? Hmm fair point I g...
by colonthree
Mon Mar 07, 2011 3:48 pm
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

Oh so thanks again for the informations guys! My next issue I'm having is DMA. I've been trying to learn how to do this before moving on to other parts of the system. I've spent a couple of days or so now trying to work this out myself referring to sega2 and genvdp.txt Even compared against TMEE's D...
by colonthree
Fri Mar 04, 2011 7:38 pm
Forum: Megadrive/Genesis
Topic: Does any sort of (user) OS or native assembler exist for MD?
Replies: 6
Views: 2485

I test on emu + real HW. If it does not work on HW i'll start deaking with idle loops and debug info displaying. Hmm, do you include debugging code in the ROM or use the debug features of an emu? or both? Are you going to edit your code with... a gamepad ?? Anyway i'm not sure that native assembler...
by colonthree
Thu Mar 03, 2011 1:14 pm
Forum: Megadrive/Genesis
Topic: Does any sort of (user) OS or native assembler exist for MD?
Replies: 6
Views: 2485

Does any sort of (user) OS or native assembler exist for MD?

I probably would have already found this by now if it did, but just incase, does anything like this exist? I'm looking for some kind of tool to quickly edit and run code on the MD itself to save me having to rewrite ROM file to SD (Everdrive) for the sake of a couple of bytes edit. As I'm still new ...
by colonthree
Fri Feb 11, 2011 1:41 pm
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

Thanks again Chilly Willy! I have other more general questions relating to programming in assembly. Probably best not to start a new thread since it follows on from my hello world thing. I'm wondering about why programmers seem to do things like use bsr for subroutines that are only run once at the ...
by colonthree
Wed Feb 09, 2011 10:25 pm
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

No such thing as an "asm compiler", but there are assemblers. The assembler converts assembly language into machine language. And yes, an assembler is needed because the compiler outputs assembly language. Ah yes, I initially wrote "assembler" and for some reason it didn't look right so I changed i...
by colonthree
Wed Feb 09, 2011 9:21 pm
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

I'm familiar with the potential for efficiency when coding with asm, otherwise probably no one would still use it (?) I was asking why there are asm compilers bundled with the sdk, considering all of the code files are written in c. Are the asm comilers still required to compile c to binary somewher...
by colonthree
Tue Feb 08, 2011 12:48 am
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

Sorry for the late reply,

Thanks for all the info!

About the everdrive sdk; i'll definitely be looking into it (right now.)
Although I'm trying to use asm over c, I'm sure the sdk will be useful :)
On that topic, why does the sdk come with some assembly apps if it's all in c?
by colonthree
Thu Feb 03, 2011 2:48 am
Forum: Megadrive/Genesis
Topic: Hello world. It works, but... (controller interrupts?)
Replies: 24
Views: 6929

Hello world. It works, but... (controller interrupts?)

So I finally got a little hello world working in emulators, thought I'd try it on hardware via Everdrive, and to my delight, it worked! A little HELLO WORLD is printed in the top left of plane a :) However, for some reason, the Licensed by Sega Enterprises Ltd remains in the middle of the screen. No...