MicroBee - The Ultimate Doppelganger #8

[someone]

Here's another ported ZX Spectrum game (with cool shadowing).
   

[Under4Mhz]

What's the story with this? Is this an actual running game, or a mockup?

[someone]

What's the story with this? Is this an actual running game, or a mockup?

It's a fully running game.

[ChickenMan]

Great, thanks, so what's the name of the game ? And when can it be shared for other members to play ?

[someone]

Great, thanks, so what's the name of the game ?  And when can it be shared for other members to play ?

It's BATTY which is a ARKANOID/BREAKOUT derivative. I don't have permission to distribute it.

[Under4Mhz]

Can you tell us more about it? Is it a conversion from the ZX spectrum version? Did you do it? If so, what was involved? Does it need particular hardware to run (teletext, 256tc etc?)

[someone]

Can you tell us more about it? Is it a conversion from the ZX spectrum version? Did you do it? If so, what was involved? Does it need particular hardware to run (teletext, 256tc etc?)

Yes.
Yes.
Someone had to do it.
The CRTC is reconfigured to display 40 columns by 32 rows of 8x8 matrix characters with only 32 columns of 24 rows used for the ZX Spectrum video.
Yes. It requires an Alpha Plus (Premium Series) and above.

Porting ZX Spectrum games should be much easier, perform much quicker and be more efficient with the Microbee Classic Plus.
It is planned to incorporate some of the simple yet powerful features that were omitted from the Alpha Plus production model including:
- Addressing the PCG, CHAR, ATTR & Colour RAM in a contiguous 16K window (to minimise the overhead of Video Memory Bank switching).
- Displaying 8x8 PCGs defined at raster row #8 (increasing PCG efficiency for 8x8 chars from 50% to 100%).

[Under4Mhz]

I'd like to hear more about your process. I've tried porting games from ColecoVision to SG-1000 which is quite challenging due to the differences in memory address space, IO space and interrupt implementations.

Do you disassemble the game? The memory map on ZX (8000-FFFF) is vastly different from the Microbee (0000-7FFF). The zx vdu is bitmap based rather than tile based, and arranged in a non-linear layout. How do you handle these challenges?

When I was porting games from the ColecoVision, I wrote a C program to do a binary search/replacing for the memory and IO space. These two systems are closer than the ZX is to the Bee. Do you have something similar? Or is it more practical to do this by hand?

Could we see a video of the game? I'd like to see how it plays.

[someone]

Have a look at the 'Porting "Real" Games to the Microbee' post to see an animated example.

As for porting, it's easiest to transform odd pixel byte layout back to a fully linear layout.
From that it's easy to port it to a microbee that uses its form of linear pixel byte layout.

As for the colour, the ZX Spectrum uses the same method to the microbee with just the RGB bit variations.