All Posts (blitter)




#1
Re: CPU General Purpose Registers
Posted on: 7/22 8:31
Virtual Freak
Joined 2007/12/14
85 Posts
CoderLong Time User (6 Years) App Coder
Short answer is yes it is compiler-dependent. At least, GCC 4 reserves r3 for the stack pointer, and the remaining registers in the range r1-r5 save for r2 are set aside for internal uses. As I look at the v810 patch, r11 may also be used for long jumps, but I've never seen that code generated in my own projects. r30 might cause a problem with bitstring instructions depending on what compiler you're using-- you can either disable the frame pointer using -fomit-frame-pointer or just use GCC 4 where it's patched to use r25 as the frame pointer. :)

There is no "OS" built into the system, nor is there a "heap" (unless you implement one)-- Whatever code you write is all that it runs. I personally have my own crt0.s that does nothing but initialize the stack, data and bss sections; the rest is handled in my C code. If you don't have any interrupts firing though, then I would say feel free to use any register you want other than r3 and I believe r31, since it's used as the link pointer for returning from the jal instruction.

Caveat emptor; it's been a while since I've done any VB coding. Maybe dasi or DogP can chime in with some insight. ;)
Top

Topic | Forum


#2
Re: Establishing a ROM Format
Posted on: 6/20 4:07
Virtual Freak
Joined 2007/12/14
85 Posts
CoderLong Time User (6 Years) App Coder
Just chiming in here-- IMO this is solving a problem that doesn't exist. Currently there are no games (or flash cart hardware for that matter) that make use of the expansion RAM, and until there are, we're putting the cart before the horse by designing a file format that we don't even know how it will be used. Like Tauwasser hinted at, VB games already know what hardware is used just by virtue of what the code does-- if the code talks to SRAM, then it uses the SRAM; if the code talks to the link port, then it uses the link port; etc.

No need to overengineer a special format describing "mappers" or other capabilities when such things are merely hypothetical right now. Just stick with the straight ROM images.
Top

Topic | Forum


#3
Re: Reproduction talk (where we are at)
Posted on: 5/5 22:33
Virtual Freak
Joined 2007/12/14
85 Posts
CoderLong Time User (6 Years) App Coder
32MBits?!? Man the project I'm working on now could *really* use that extra space... How soon until I can order one? ;)
Top

Topic | Forum


#4
Re: First time you heard of the Virtual Boy
Posted on: 4/14 1:11
Virtual Freak
Joined 2007/12/14
85 Posts
CoderLong Time User (6 Years) App Coder
Display unit at Toys 'R' Us, back probably around 1996, because it was right on the cusp of when the N64 was about to be released. There were (original) Game Boy displays, N64, SNES, PS1, and Saturn kiosks set up. Every once in a while you'd see a Pico too. *rolls eyes*

I joined PVB in 2007 while in college, after lurking for a couple of years. Had just bought my first VB off of a childhood friend of mine and thought it would be fun to develop for. Back when David Tucker and Alberto would still pop in every once in a while... ;)
Top

Topic | Forum


#5
Re: All hail the Virtual Boy
Posted on: 4/12 6:46
Virtual Freak
Joined 2007/12/14
85 Posts
CoderLong Time User (6 Years) App Coder
The way the VB is designed, you're supposed to hold the controller *behind* the stand, almost like you're hugging the VB as you play. When the stand is backwards it makes holding the controller that way difficult to do comfortably.
Top

Topic | Forum


#6
Re: All hail the Virtual Boy
Posted on: 4/11 23:47
Virtual Freak
Joined 2007/12/14
85 Posts
CoderLong Time User (6 Years) App Coder
Anybody else notice Reggie's VB has the stand on backwards?
Top

Topic | Forum


#7
Re: Virtual Boy at GDC
Posted on: 3/31 21:51
Virtual Freak
Joined 2007/12/14
85 Posts
CoderLong Time User (6 Years) App Coder
The text on the placard next to it reads:

"In 1995, the videogame market was literally packed with options, so it is no surprise that Nintendo's unusual Virtual Boy system came and went in a flash. A standalone console, the Virtual Boy features a red and black display with impressive built-in 3D capabilities, if you can get through more than 15 minutes without a migraine! Seriously, we love the Virtual Boy, which will always hold a place in the history of videogaming."
Top

Topic | Forum


#8
Virtual Boy at GDC
Posted on: 3/31 21:41
Virtual Freak
Joined 2007/12/14
85 Posts
CoderLong Time User (6 Years) App Coder
As a game dev, I get to go to GDC every year, and this year the Videogame History Museum put together a spread dedicated to the "History of Nintendo," stretching all the way back to the Color TV Game. There were Nintendo consoles of all kinds set up for the public to play, including the Virtual Boy. However, most of these systems were in mint or near mint condition except for-- you guessed it-- our red and black friend.

The VB was mounted on the display stand, which although it was pretty neat that they had one, the adjustable piece was broken (too loose) and as a result I had to rest the head unit on my face as I played. The VB was loaded with Red Alarm, but as you can see in the attached photo, the right display suffered from the glitchy lines problem. I suspect this is why a lot of people would walk up to it, look in for a few seconds, then leave.

Attach file:



jpg  IMG_3229.JPG (2,705.18 KB)
676_5339c4b3f20db.jpg 3264X2448 px

jpg  IMG_3230.JPG (1,476.99 KB)
676_5339c61575a5e.jpg 2448X3264 px
Top

Topic | Forum


#9
Re: VSU Sandbox
Posted on: 3/12 23:31
Virtual Freak
Joined 2007/12/14
85 Posts
CoderLong Time User (6 Years) App Coder
Update: Fixed a bug with channel 5 and setting properties of the EV1 register.

Attach file:


zip VB Sound Generator.zip Size: 369.44 KB; Hits: 10
Top

Topic | Forum


#10
Re: VSU Sandbox
Posted on: 3/12 10:15
Virtual Freak
Joined 2007/12/14
85 Posts
CoderLong Time User (6 Years) App Coder
Mine is written in Objective-C++/Cocoa, so you're only going to be able to compile it on a Mac. ;) The VSU and audio engine parts are written in C++ though, so really only the GUI part would have to be rewritten.

Even though I cautiously left space in the GUI for it in the lower right, I didn't port over your entire vb_snd_gen, just the part that generates the audio. I modified it to generate it on the fly, since my primary motivation was to play around with the noise channel in order to find register values of percussion sounds I liked for my music engine. Creating files and playing them back simply took too long. ;) I pretty much took inspiration from this mock screenshot http://www.planetvb.com/modules/newbb ... ost_id=9560#forumpost9560 but stopped short of porting over the sequencer/code generation aspect of what you did, since I didn't need that. :P

The waveform-based emulation code is pretty accurate to my ears, down to the aliasing artifacts-- haven't done a wave-to-wave analysis vs. the hardware though. Verdict is still out on the noise channel, after also messing with it in Mednafen. Will have to try on hardware soon. However I'm still not sure how "interval" actually works, since both in that generator and in my own experiments writing for the VSU, all I get is silence. I must be doing something wrong.
Top

Topic | Forum




You are not logged in.
Lost Password?
Register Resend Activation