nesdev.com

To play GG games on a TV you're better off using one of the GG TV modifications on a GG itself. GG mode changes how controller input works and few other tidbits like NMI no longer is pause but communications interrupt instead and SMS hardware cannot do any of it, all of the SMS stuff needs to get re...

There are not many off the shelf sound chips, Lidanriq has pretty much nailed the options. Sawtooth is very easy to do on a FM chip, requiring only two operators to produce the all harmonics ramp that sawtooth has. Squarewave is also easy with same method, only difference being multiplication factor...

GG VDP outputs 5 bit digital RGB (4 index + 1 palette bit) and couple support signals to tell when something starts and ends, plus each PSG channel on its own pin. Palette and other stuff is applied externally by the second chip on early versions (later ones integrate everything into single chip). T...

Those "teeth" on top look nice lol

There's no "new" video mode as far as VDP goes though, the VDP still outputs full NTSC image. When the !GG pin is put low a chip that does IO ports stuff applies new palette to the image and also a border (you need to manually turn rendering off outside the LCD area to get extra VRAM bandwidth) and ...

PSG should have been clocked at half speed, lack of bass notes is what hurts it the most but that wouldn't make it match NES in any way, there's still only 3 types of sounds possible (50% sq, 6.25% sq, white noise) while NES can do much much more. YM2413 was underutilized, most games used music data...

I use EDIT.COM and ConTEXT, because I require cursor to be freely placed anywhere in the editable area. I'm very slowly working on my own thing which is more (assembly) programming orientated.

Ristar has a swinging mechanic used throughout the game to reach high places and whatnot and it is used at end of the stages to gain additional bonus that increases with height of going off screen.

It looks like something for those guitarsomething music games.

Yes, you can do that. What you do on current line gets to be seen on the next.

SMS gives one access slot every 32 pixels during active line (8 total) and 11 more during offscreen parts but they are clustered together and you can only hit couple of them in best case, so at most you can write 11 bytes total. SMS VRAM bus is 16 bit but CPU interface is 8 bit so half the bandwidth...

My "flagship" SMS project won't even work on JP SMS due to limited cartslot of the platform compared to US/EU machine, I am not concerned at all about lack of MD compatibility. The people who are going to play the game have SMS anyway.

Only way I can think of is to switch to TMS modes since they cannot be scrolled and always appear in fixed location on the screen.

Any freq write resets the LFSR to 1000 0000 0000 000(0) and the noise/square setting turns off the feedback, so single bit loops through it continuosly, producing (100/16 or 15)% duty cycle depending on VDP or TI PSG.

tepples wrote: ↑

Tue Dec 17, 2019 9:51 pm

periodic noise

It shouldn't be called as such, it is 6.25% duty cycle square wave on VDP PSG (SMS and MD) and 6.666...% on real TI chips.