PC Engine - Mega Drive Hardware comparison

[Django!]

(Hope this is the right forum)

Topic came up in another discussion on another forum. On first glance, both systems seem to have similar clock speeds. The PC Engine had selectable speed. 1.79 or 7.16 MHz. Genesis clocked at 7.67. Both had similar resolutions 256×240 and 256x224 for the PC Engine/Mega Drive respectively.

Both have 512 colors available, and could display 64 sprites on screen each.

Specifically mentioned was the PC Engine's hardware scaling.

One of the games that came up was Bomerman 94 versus Mega Bomberman.

http://www.youtube.com/watch?v=4-4b6Mf9ydE
PC Engine

http://www.youtube.com/watch?v=ym0WlMvRGd0
Genesisi

There's also the comparison between Snatcher for both systems as well, disregarding extra content and such.

I was just looking for some clarification and further information, please.

[drx]

First of all, comparing clock speeds of two (significantly!) different CPU architectures is meaningless.

Second of all, comparing the same game for different consoles and judging the consoles by that isn't fair. For all you know, the developers could have made a crappy port for one system (or another), while the other is much better (worse). This could mean one system is 'better' than another, but then again, it might just mean that the developers did a half-assed job at porting.

[Django!]

Hence why I have appealed to the Assembler boards for "clarification and further information"... please.

:-)

[la-li-lu-le-lo]

From what I remember, the PC Engine isn't really 16-bit. It has a 16-bit GPU, but the CPU is still 8-bit. The Mega Drive, however, is all 16-bit. Someone please correct me if I'm wrong.

[opethfan]

From what I remember, the PC Engine isn't really 16-bit. It has a 16-bit GPU, but the CPU is still 8-bit. The Mega Drive, however, is all 16-bit. Someone please correct me if I'm wrong.

If you feel like pusing the envelope a bit, you could say that the Mega Drive is 32 bit, as the 68000 had 32 bit registers, but a 16 bit bus.

But yeah, it was 16 bit :110:

[ccovell]

The PCE can do resolutions of up to 565x242 pixels; the MD, 320 x 448 (480 in PAL(?))
The PCE can display 64 sprites on screen; the MD, 80.
The PCE does NOT have hardware scaling, nor does the MD. What forum spread this misinformation?

So to save us a lot of needless rewriting, here are some relevant topics in other places that discuss the PCE/MD in depth. Makes for interesting reading too!

http://www.pcenginefx.com/forums/index.php?topic=3663.0
http://www.pcenginefx.com/forums/index.php?topic=1928.0
http://www.pcenginefx.com/forums/index.php?topic=2468.0

And here: http://forums.magicengine.com/en/viewtopic.php?t=1798
for a resolution program I made for the PCE.

[kendrick]

From what I remember, the PC Engine isn't really 16-bit. It has a 16-bit GPU, but the CPU is still 8-bit. The Mega Drive, however, is all 16-bit. Someone please correct me if I'm wrong.

It's strange, but the PC-Engine CPU is a custom chip (HuC6820) that functions as a pair of 6502 processors running in parallel. It's close enough that the portable unit (the TurboExpress or whatever) actually has two 6502s in it, with some firware to emulate the extra instructions in the HuC6820. So essentially, the only way to get 16-bits out of the PC-Engine CPU is by adding together the two 8-bit processors.

In the spirit of citing sources, the venerable TurboGrafx FAQ has all this info and quite a bit of programming data as well. The veterans around here already know this stuff, so this is just to get it in the thread:

http://www.gamefaqs.com/console/turbo16/file/916398/5708

[Shadowlayer]

So essentially, the only way to get 16-bits out of the PC-Engine CPU is by adding together the two 8-bit processors.

And in that case we could say the Genesis (and the AES for that matter) is a 24bit console;-)

[AntiPasta]

It's strange, but the PC-Engine CPU is a custom chip (HuC6820) that functions as a pair of 6502 processors running in parallel.

Are you absolutely sure of this? I looked up some info and couldn't find anything backing this up.. how is this implemented in the ISA? Two instruction paths, or some P5-style interleaving?

[ccovell]

Kendrick is spouting bullcrap (for the sake of fun, I sure hope...), and linking to same as well.

The HuC6820 is an 8-bit chip that only has 1 PC, and fetches data sequentially. There's no parallel processing going on, even with the really fast block transfers and other added goodies.

[AntiPasta]

I figured, it'd be fun to have OOE/superpipelining in an 8-bit CPU :033: