Author Topic: Gameboy Ports?  (Read 6556 times)

0 Members and 1 Guest are viewing this topic.

Offline Executioner

  • Supporter
  • 6128 Plus
  • *
  • Posts: 783
  • Country: au
  • WinAPE Developer
    • WinAPE
  • Liked: 391
  • Likes Given: 60
Re: Gameboy Ports?
« Reply #25 on: 14:38, 13 September 11 »
Don't get me wrong, I would love to see such games on our CPC; but it just can't be any kind of related ports, only adaptations are possible.

Well, actually I'd tend to disagree with that statement to some extent. A LOT of the game logic could be re-used, this is the most important thing (the original BONUS code for Bubble Bobble springs to mind). The only real difficulty is doing similar graphics and sound without the advanced sprite hardware of the GB, but it might not matter so much if the parallax isn't there so long as the game-play is as the original. Besides, we'll have some nice colours in our graphics unlike the GB originals.

Offline MacDeath

  • Chaotic post writer and mock-up specialist
  • Supporter
  • 6128 Plus
  • *
  • Posts: 4.060
  • Country: fr
  • Liked: 1167
  • Likes Given: 649
Re: Gameboy Ports?
« Reply #26 on: 15:53, 13 September 11 »
Well, up to check wether the "engine" code take a lot of the CPU or not... independently to Sprites and stuff management.
Quote
Technical specifications
  • CPU: Custom 8-bit Sharp LR35902[28] core at 4.19 MHz which is similar to an Intel 8080 in that all of the registers introduced in the Z80 are not present. However, some of the Z80's instruction set enhancements over the stock 8080, particularly bit manipulation, are present. Still other instructions are unique to this particular flavor of Z80 CPU. The core also contains integrated sound generation.[29]
  • RAM: 8 kB internal S-RAM[30] (can be extended up to 32 kB)[31]
  • Video RAM: 8 kB internal[31]
The CPU is not exactly a Z80.
Gotta have a look if some stuffs are not better on a Z80.
Also goota see if the "other unique instructions" are often used or not.

the CPU must really work lightly on Game boy "average game"...
Few actuall RAM, all ROM based and Hardware effect based.

Some stuff on Amstrad are totally non-existent on GameBoy.

Palettes and raster managements...
soft Sprites and stuffs.

also virtually 2x less VRAM used = 2x less scanlines interrupts and so on.

Gameboy runs as lightweight as a Speccy on the VRAM.


The CPU seems to handle most of the sound, so this can be quite different from an AY controlled by the Z80.

« Last Edit: 15:58, 13 September 11 by MacDeath »

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 11.645
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 4176
  • Likes Given: 436
Re: Gameboy Ports?
« Reply #27 on: 16:10, 13 September 11 »
The GB CPU is based on an 8080, but it has a few op-codes that the Z80 doesn't have and a few are missing that the Z80 has. As well as that, the op-codes are different in some circumstances, so you're going to have to do a "search and replace" on those too.

Gone:
The IX and IY registers are missing. There are no IN or OUT instructions, no exchange instructions and conditional jumps also don't exist in the form that they do in a Z80.

Added:
There are quite a few new LD commands (Load and increment, Load with address offset, etc), a STOP command (wait for button press) and a SWAP command (high/low nibble).

That's quite a bit of changing and checking to do before it will be even close to running on a Z80. A rewrite is probably much easier.

Bryce.

Offline MaV

  • Supporter
  • 6128 Plus
  • *
  • Posts: 1.102
  • Country: at
  • Ius summum saepe summa est malitia.
  • Liked: 399
  • Likes Given: 825
Re: Gameboy Ports?
« Reply #28 on: 16:24, 13 September 11 »
The only Gameboy game on the Amstrad that I'll accept will have its colours optimized for the green screen. :P
Black Mesa Transit Announcement System:
"Work safe, work smart. Your future depends on it."

Offline SuTeKH/Epyteor

  • 6128 Plus
  • ******
  • Posts: 1.363
  • Country: 00
  • Liked: 1283
  • Likes Given: 2022
Re: Gameboy Ports?
« Reply #29 on: 16:52, 13 September 11 »
Still bored with life... so still ***ing around!

Updated SML2 with two more tunes from the start of the game... thanks YouTube, thanks for nothing! Obviously, someone with more experience with the CPC sound chip can do a much better job with a 'real' version, if one is ever created.
« Last Edit: 16:54, 13 September 11 by tastefulmrship »

Offline EgoTrip

  • 6128 Plus
  • ******
  • Posts: 1.051
  • Country: gl
    • http://egochip.blogspot.co.uk/
  • Liked: 677
  • Likes Given: 294
Re: Gameboy Ports?
« Reply #30 on: 18:11, 13 September 11 »
If your that bored, maybe in your next mockup you could have mario move around and interact with enemies and blocks and stuff.
EgoTrip's Stuff
EgoTrip's Stuff

Offline MacDeath

  • Chaotic post writer and mock-up specialist
  • Supporter
  • 6128 Plus
  • *
  • Posts: 4.060
  • Country: fr
  • Liked: 1167
  • Likes Given: 649
Re: Gameboy Ports?
« Reply #31 on: 08:44, 14 September 11 »
Quote
The only Gameboy game on the Amstrad that I'll accept will have its colours optimized for the green screen.
Then every mode1 games on Monogreenscreen is somewhat GameBoy flavoured. :laugh:

Offline MaV

  • Supporter
  • 6128 Plus
  • *
  • Posts: 1.102
  • Country: at
  • Ius summum saepe summa est malitia.
  • Liked: 399
  • Likes Given: 825
Re: Gameboy Ports?
« Reply #32 on: 12:06, 14 September 11 »
Then every mode1 games on Monogreenscreen is somewhat GameBoy flavoured. :laugh:

Hehe!

Mainly Voice: "Gameboy? Yeah, I got one of those. But mine has a proper monitor." :D
Black Mesa Transit Announcement System:
"Work safe, work smart. Your future depends on it."

Offline dragon

  • 6128 Plus
  • ******
  • Posts: 1.438
  • Country: es
  • Liked: 595
  • Likes Given: 490
Re: Gameboy Ports?
« Reply #33 on: 20:14, 19 September 11 »
o.K.If you search play a game boy games in the amstrad(other stupid sugerence XD).Maybe you need a game boy.

So the super game boy of supenes is a game boy without lcd  and buttons.(the snes is not powerful to emulate gameboy).

Maybe is posible create a interface amstrad->super gameboy?.

http://www.vilecha.com/Neo/images/SuperGameBoy.gif

The snes uses a special chip as interface with game boy:
http://www.dforce3000.de/pub/d4s_super_gameboy_notes.pdf
« Last Edit: 20:26, 19 September 11 by dragon »