Author Topic: How many bits is Data East's DEC0 hardware?  (Read 4669 times)

Offline synnchan

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How many bits is Data East's DEC0 hardware?
« on: November 22, 2016, 03:36:36 PM »
I noticed some Data East games (such as Bad Dudes vs DragonNinja, Heavy Barrel, Midnight Resistance, etc) are classified as "DEC0 hardware". What does that mean exactly? I know DEC8 and DECO IC16 are obviously 8 bits and 16 bits respectively (and I'm guessing Simple 156 would be 32 bits).

But what about DEC0? I know for sure it's not 0 bits because you can't have a game with 0 bits. :P

Offline Gab75

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Re: How many bits is Data East's DEC0 hardware?
« Reply #1 on: November 22, 2016, 04:31:16 PM »
I think that Data East "DEC-0" can be classified as a 16 bit system... MC68000 (10 or 12 MHz) as main CPU and HuC6280 (1.5 or 3 MHz) as secondary CPU.

Offline synnchan

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Re: How many bits is Data East's DEC0 hardware?
« Reply #2 on: November 22, 2016, 08:08:47 PM »
Thanks for the info, Gab75! I've been curious about it for a while. :)

Offline Gab75

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Re: How many bits is Data East's DEC0 hardware?
« Reply #3 on: November 23, 2016, 12:34:46 AM »
You are welcome! :)

Offline iq_132

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Re: How many bits is Data East's DEC0 hardware?
« Reply #4 on: November 23, 2016, 08:08:19 AM »
I noticed some Data East games (such as Bad Dudes vs DragonNinja, Heavy Barrel, Midnight Resistance, etc) are classified as "DEC0 hardware". What does that mean exactly? I know DEC8 and DECO IC16 are obviously 8 bits and 16 bits respectively (and I'm guessing Simple 156 would be 32 bits).

But what about DEC0? I know for sure it's not 0 bits because you can't have a game with 0 bits. :P
In the traditional sense the amount of bits a gaming system was based on the opcode size the cpu could process.
Opcodes are the commands the cpu can process.  CPUs like z80, m6502, m6800, m6809, konami custom, etc are 8 bit. M68000 is a 16 bit cpu as is the recently ported V60.
CPUs like ARM, ARM7 (arm7 has thumb mode that is 16 bit iirc), V70, and mc680ec0 are 32 bit. ^^

Deco-16 games are generally considered Data East Co. 16 bit games. These use the M68000 a 16 bit cpu.
The Deco32 games use an ARM processor (32-bit). Dec8 uses M6809 (or variants of) which are 8-bit.

Dec0 doesn't use this naming scheme even though it is 16-bit.


Additionally, someone mentioned the huc6280, that's actually an 8-bit cpu. ^^ It's a souped-up m6502 iirc.


Offline Gab75

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Re: How many bits is Data East's DEC0 hardware?
« Reply #5 on: November 23, 2016, 08:48:06 AM »
In the traditional sense the amount of bits a gaming system was based on the opcode size the cpu could process.
Opcodes are the commands the cpu can process.  CPUs like z80, m6502, m6800, m6809, konami custom, etc are 8 bit. M68000 is a 16 bit cpu as is the recently ported V60.
CPUs like ARM, ARM7 (arm7 has thumb mode that is 16 bit iirc), V70, and mc680ec0 are 32 bit. ^^

Deco-16 games are generally considered Data East Co. 16 bit games. These use the M68000 a 16 bit cpu.
The Deco32 games use an ARM processor (32-bit). Dec8 uses M6809 (or variants of) which are 8-bit.

Dec0 doesn't use this naming scheme even though it is 16-bit.

Thanks for the explanation! :)

If I'm not wrong, the original ARM7 uses a design similar to ARM6, so it has only the 32 bit ARMv3 ISA... differently the variant ARM7TDMI (ARMv4t) adds a 16 bit Thumb istruction set to improve the compiled code density.

Out of curiosity: Does the NEC V60 uses 32 bit or 16 bit opcodes? As far as I know, the NEC V60 should be a 32bit CISC CPU, the external data bus is 16 bit, but internally the microprocessor is fully 32 bit (ISA, registers, ALU, internal bus).

Additionally, someone mentioned the huc6280, that's actually an 8-bit cpu. ^^ It's a souped-up m6502 iirc.

Yes HuC6280 is an improved version of the M6502, made by Hudson... it should have various additional instructions, some internal peripheral functions and (IIRC) an embedded PSG (Programmable Sound Generator).

Offline synnchan

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Re: How many bits is Data East's DEC0 hardware?
« Reply #6 on: November 23, 2016, 09:38:04 PM »
Thanks for the explanation, iq_132. I enjoy learning about those things. ^^

EDIT:

By the way, system16 says Act Fencer and Trio the Punch use HuC6280 for main processor. Are those games really 8 bit? their graphics look more like 16 bits to me (a little advanced for 8 bits).
« Last Edit: November 24, 2016, 08:36:08 AM by synnchan »

Offline Haze

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Re: How many bits is Data East's DEC0 hardware?
« Reply #7 on: November 24, 2016, 03:31:48 PM »
it's a meaningless metric used for marketing, nothing more.

e.g the whole claims that neogeo was '24-bit' because it has a 16-bit 68k and 8-bit z80 (by the same logic the Megadrive is also 24-bit tho, which is where the irony comes from because they were quick to claim that was 16-bit)

most of the video chips found in the systems have 8 or 16-bit buses, even when used with newer CPUs; for example, the Megadrive graphic chip is actually an evolution of the 8-bit one used in the Master System and still operates on an 8-bit bus.

things like Lethal Enforcers by Konami pair up graphic chips typically used on 68k driven platforms with an older 8-bit CPU (really looks like that game was made to clear out excessive parts)

but as I said, it's an utterly meaningless metric, especially with arcade hardware because you see chips from different generations intermixed all the time.  What matters is how things were used and what they were paired with.

take PGM, te main CPU is a 16-bit 68000 processor, some of the PROTECTION cpus in the cartridges (used for nothing but protection checks) are 32-bit ARM processors, more powerful than the actual system base system.  there are quiet a few examples of this actually, presumably because the game programmers were more familiar with certain CPUs, so stuck with those, while the people working on the protection systems used newer CPUs but barely made any use of them.

how many 'bits' a system is has nothing at all to do with visual quality, and doesn't even tell you much about a system in general.