DSP in a HuCard & Max Storage Size of a HuCard

[nodtveidt]

MSR took a long time to complete mainly because it was a learning experience... and real life got in the way a LOT. If we were to actually lay out how much time was really spent putting it together... and I'm referring to all the work that went into the finished product... it might not have exceeded a year, maybe 15 months, of "commercial time". Also, I started it in early 2005, so it's not even close to 10+ years. It was started not long before my first child was born, and she's only 6.

[SignOfZeta]

I can certainly understand that programmers of today aren't as great at dealing with the minuscule amounts of memory and storage that the guys in the 80s/90s were, and therefore would in theory benefit greatly from something other than Super CD format. Something like how NG: Dev is making Neo carts as huge as GBA carts, and it shows. After all, SuperCD is like trying to drink a fish tank full of booze one shot glass at a time. WHY IS THE FISHTANK SO BIG IF ALL I HAVE IS THIS SHOT GLASS!?

But in the end those aren't the only limits they are going to hit, and it makes me wonder if nearly limitless HuCard storage is really, in the end, going to make that much of a difference. Don't you kind of have to be "in the zone", fully mentally, strategically, committed to a 8 bit way of doing things to really kick ass on the PCE? I suppose it would help, but you still aren't going to be able to make Garou: Mark of the Wolves or Dondanpachi without some serious f*cking skill, no matter what the storage method is. The Arcade Card is out there, with a f*cking ridiculous amount of storage, but I still haven't seen anyone port KOF 94 to it.

That would be a great project, btw. KOF 94 AC.

[Arkhan]

MSR took a long time to complete mainly because it was a learning experience...

in that learning experience, you probably realized "shit, maybe next time these cutscenes/art should be planned out a bit better".

I wonder how many times a game like CF had the art sized down, or if the art team was told "this is your size limit.  f*ck you if you don't like it!"

lol

[nodtveidt]

That's why I was very selective in which frames to cut... the scenes still had to be portrayed correctly, but I could only cut so much before the effect was lost. Cutscene 2 is the most packed cutscene in the game, and it really shows... I had to letterbox quite a few frames just to get enough frames in.

SoZ, my initial background is in the Commodore 64. I'm very experienced in working with severely limited resources. You simply switch mindsets when you work with a much larger platform, such as the PC or the 360... you go from "how much can we stuff into this" to "how many polys can we push per frame".

[Arkhan]

f*ck the C64!  That things retarded for programming, lol.

Ever notice how most of the hardcore C64 coders still kickin today are wacko?

[nodtveidt]

Dude, most retro programmers in general still kickin today are wacko, present company included.

[Arkhan]

Theres wacko, and then theres C64 wacko.

[spenoza]

Wait, I don't see how SuperCD was a limited medium for Mysterious Song. Cutscenes, yeah, but good map design which promotes reasonable loading breaks should free you from most RPG limitations. Just avoid huge sections that need a single load.

Back to the HuCard issue... I'd much rather see some scratch RAM on a HuCard than a DSP. Even a little 128 kibit blorp of read/write RAM that the CPU could use to decompress data into or use for storing extra variable and data would be fantastic. The question is, how much additional complexity would a RAM/ROM mapper and a small RAM chip add? This would, effectively, be the SuperCD Card of HuCards.

[Necromancer]

Back to the HuCard issue... I'd much rather see some scratch RAM on a HuCard than a DSP. Even a little 128 kibit blorp of read/write RAM that the CPU could use to decompress data into or use for storing extra variable and data would be fantastic. The question is, how much additional complexity would a RAM/ROM mapper and a small RAM chip add? This would, effectively, be the SuperCD Card of HuCards.

Wouldn't access to ram on the huey be just as slow as accessing anything else on the rom?

[spenoza]

I don't know that that would be a problem. And ROM is pretty fast, at least fast enough. The Super System card adds flexibility because it is writeable, not just a ROM store, and the limited memory of the PCE is often a bottleneck, so be expanding the RAM area via a HuCard you allow HuCard games to do some of what SuperCD games have been able to do for a while.

[Mednafen]

If I were to design a special mapping chip for a HuCard, it would have a 64x8-bit FIFO(writeable via HuC6280), with its output clocked at a semi-programmable rate(say 32KHz / (2**n), where n is 0-2) connected to an adder that adds(at a fixed rate of 32KHz) the 8-bit value(sign-extended, and shifted left by "2 - n") to a 10 bit latched value, and latches the 10-bit result, and the upper 8-bits of the 10-bit result latch are fed to an 8-bit DAC, which is routed to the audio pin of the HuCard.

Additionally, it would have a feature that allows for ROM data to only appear at odd addresses, and a value alternating between 0x13 and 0x23 to appear at even addresses, such
that a data block like: 0xDE 0xAD 0xBE 0xEF
would become: 0x13 0xDE 0x23 0xAD 0x13 0xBE 0x23 0xEF

Oh, and of course it would have ROM bankswitching abilities, too.


I think this is all reasonably simple functionality, and something that would have been technically feasible and cost effective during the PC Engine/TG16's heyday.


Edit: Fixing issues with my description of the audio playback functionality, I shouldn't post technical descriptions while still half-asleep.

[thesteve]

true

i figured use a ram chip in the card and have 1 address set 8 bit address extending the addressing to 28 bits.
could be just an 8 bit register.
set an audio player to use its own rom for the aud pin with fixed sample sizes that can be called as single addresses

[BigusSchmuck]

Theres wacko, and then theres C64 wacko.

Hey thats how I learned how to program back in the day. So I guess my question is this: whats stopping us from creating our own arcade cards if RAM is so cheap these days? Just a thought considering people are saying how limited the Super CD is..

[TailChao]

If I were to design a special mapping chip for a HuCard, it would have a 64x8-bit FIFO(writeable via HuC6280), with its output clocked at a semi-programmable rate(say 32KHz / (2**n), where n is 0-2) connected to an adder that adds(at a fixed rate of 32KHz) the 8-bit value(sign-extended, and shifted left by "2 - n") to a 10 bit latched value, and latches the 10-bit result, and the upper 8-bits of the 10-bit result latch are fed to an 8-bit DAC, which is routed to the audio pin of the HuCard.

I was actually thinking of something like this for another platform, and if you have the mapper already passing the datalines from the ROM to the PCE's databus, you could just have the mapper fetch the bytes for you when the CPU isn't doing a read cycle

Additionally, it would have a feature that allows for ROM data to only appear at odd addresses, and a value alternating between 0x13 and 0x23 to appear at even addresses, such
that a data block like: 0xDE 0xAD 0xBE 0xEF
would become: 0x13 0xDE 0x23 0xAD 0x13 0xBE 0x23 0xEF

This is really clever, haha.

I think this is all reasonably simple functionality, and something that would have been technically feasible and cost effective during the PC Engine/TG16's heyday.

It's very strange that NEC/Hudson didn't do more with mappers, especially since both had so much background in chip design. I guess CD was their thing. Something like you describe in an ASIC would be pennies for them.

[nodtveidt]

Wait, I don't see how SuperCD was a limited medium for Mysterious Song. Cutscenes, yeah, but good map design which promotes reasonable loading breaks should free you from most RPG limitations. Just avoid huge sections that need a single load.

You also don't have an idea of how complex MSR is under the hood. Don't be deceived by what appears to you to be "simple"... RPGs require a ridiculous amount of code. Couple that with the blatantly obvious design shortcuts and limitations of HuC itself... and maps are the least of your worries.