GB TETRIS EMULATOR TEMU FOR AMSTRAD CPC 6128(+)

[Gryzor]

Damn all the files I tried today failed... Is it so hard to find the correct ROM or was I just unlucky?

[TotO]

Damn all the files I tried today failed... Is it so hard to find the correct ROM or was I just unlucky?

Did you add the Amsdos header?

[Gryzor]

Yes I did, I read all the instructions here...

But finally... all is well And awesome!!!

[40Crisis]

Hi @40Crisis Can you tell us how the emulator works?
Thank you

GB Hardware emulation is quite easy because I/O is done on the GB through memory registers (not ports).
A few rom traps are needed to render graphics, sound and input.GB Sharp LR35902  code is executed as is  on CPC Z80 because it's a modified Z80 with a few different instructions. 9 extra instructions not present in z80 are needed for emulating tetris.
They are emulated using the eight RST instructions available on the Z80. It takes me time to figure out how to do it without loosing too much speed. This is quite slow but does the job.
Graphics rendering is done on CPC by only displaying changing areas. Graphics are rendered asynchronously when there's enough time after the gameloop rendered at 60Hz. Average measured framerate is about 25 Hz ingame.

[40Crisis]

Woaahh this reminds me the excitement I got when I discovered Syx/TotO's PacMan emulator few years ago..!

Splendid, I'm sincerely impressed.

Please, release a V2 with some (if not all..) of the improvements from TotO !

Thanks for your nice feedback
I'll try to do my best to include improvements from TotO

[SyX]

Woaahh this reminds me the excitement I got when I discovered Syx/TotO's PacMan emulator few years ago..!

Merci!!! You made my day happy... waiting for a really happy day when you release your next Mega Production

And of course, AMAZING WORK @40Crisis!!! 

I know that being Tetris a really famous game and after this wonderful result, this project will get you a lot of acclaim in the community, but you deserve that because along of the years you have brought to the CPC great classic games and I will play and enjoy them until your next project arrive. ¡Muchas Gracias! 

[roudoudou]

thank you for all explanations 

9 extra instructions not present in z80 are needed for emulating tetris.
They are emulated using the eight RST instructions available on the Z80.

ok so the emulator has to know where is the code and the data, it's not plug'n'play 
with a little rework of the original code using those instructions, we may expect more native power

[Gryzor]

OFF-TOPIC:

@40Crisis : please fix your email address in your profile settings, all notification emails are bouncing back

[TotO]

Here a 4 colours 256x256 (16K) bezel picture. (PNG and BIN)
The areas match with a palette change using the Gate Array interrupts.
May be nice to use this format to allow peoples to provide their own "BEZEL.BIN" file.

CPC palettes:
- 9, 13, 12, 25
- 1, 13, 3, 26

PLUS palettes:
- 333, 777, 896, CDA
- 007, 777, 700, EEE

[TotO]

In example, with the Amstrad CPC and Amstrad Plus palettes and rasters

[Gryzor]

Never understood the appeal of running Gameboy have on a Big Screen with marquees until now 😁

[Joseman]

Hi @40Crisis

This isn't coding this is just MAGIC.

I always thought that porting small games from the gameboy was reasonably feasible on CPC.

I didn't know how and the explanation you give is really magic for my ears.

I have remembered my years with the gameboy with your port and it's exactly the same.

Congratulations!!

P.S. will you release the sourcecode for another people to port other games or do you think on make other ports?

[norecess464]

@40Crisis  One small request: while CAPS LOCK key may be a good idea on real CPC keyboards, please can you also add another mapping for it (SHIFT, CONTROL..) ? Many people will probably run the game through an emulator, and the CAPS LOCK key is absolutely not convenient for that purpose on PC keyboard.

[Longshot]

@40CrisisYou did work on a very interesting subject.
Bravo for this achievement! 

I am amazed to see that there are no ld (a16),hl and ld hl,(a16) instructions on LR35902 processor.
The replacement for ld (hl-),a and ld a,(hl-) is delicate since they replace instructions that already exist with other opcodes (ld a,(a16)/ld (a16),a)

If I could make a few remarks:

You forgot to remove one ld (hl),a from the routine that patches the memory with bytes, just before running the rom. (thus doubling ld (hl),a)
(a remainder of the copy/paste routine that patches the memory with words)

You don't need to use DI at the begining of your interrupt routine (called in vectorized mode under IM2 mode)
No other interrupt can occur until the ei/ret (reti not needed)

I think you can improve the swap a and swap e instructions, which you simulate with the rst38h instruction by setting the Carry Flag
For swap a (cb 37), I think you can just do rrca/rrca/rrca/rrca
For swap e (cb 33), I think you can just do rrc e/rrc e/rrc e/rrc e
For this latter instruction, which you patch once at 6db0 in the ROM, I think there is a bug:

Code Select Expand

ld e, a
exx
ex af, af '
ret

instead of

Code Select Expand

exx
ld e, a
ex af, af '
ret

Can you tell us more about the management of the graphical interface?
Do you have a unique periodic rendering routine for data generated by the GB in its IO space?

[40Crisis]

@40CrisisYou did work on a very interesting subject.
Bravo for this achievement! 

It's an honor to have a CPC Legend commenting my project

I am amazed to see that there are no ld (a16),hl and ld hl,(a16) instructions on LR35902 processor.
The replacement for ld (hl-),a and ld a,(hl-) is delicate since they replace instructions that already exist with other opcodes (ld a,(a16)/ld (a16),a)I was aware of this problem and replacement needs to be done in a particular order
If I could make a few remarks:

You forgot to remove one ld (hl),a from the routine that patches the memory with bytes, just before running the rom. (thus doubling ld (hl),a)
(a remainder of the copy/paste routine that patches the memory with words)
You're right copy and paste is not a good habit when coding but so convenient

You don't need to use DI at the begining of your interrupt routine (called in vectorized mode under IM2 mode)
No other interrupt can occur until the ei/ret (reti not needed)Thanks for the info, will try it
I think you can improve the swap a and swap e instructions, which you simulate with the rst38h instruction by setting the Carry Flag
For swap a (cb 37), I think you can just do rrca/rrca/rrca/rrca
For swap e (cb 33), I think you can just do rrc e/rrc e/rrc e/rrc eMuch more clever and efficient that the one I wrote
For this latter instruction, which you patch once at 6db0 in the ROM, I think there is a bug:

Code Select Expand

ld e, a
exx
ex af, af '
ret

instead of

Code Select Expand

exx
ld e, a
ex af, af '
ret
You're absoluty right about the bug, what a good sight you have

Can you tell us more about the management of the graphical interface?
Do you have a unique periodic rendering routine for data generated by the GB in its IO space?
Yes there's one rendering routine fo background titles and one for the sprites ( splitted in 8 multiple aligned or not)

[40Crisis]

@40Crisis  One small request: while CAPS LOCK key may be a good idea on real CPC keyboards, please can you also add another mapping for it (SHIFT, CONTROL..) ? Many people will probably run the game through an emulator, and the CAPS LOCK key is absolutely not convenient for that purpose on PC keyboard.

Very good suggestion

LEFT SHIFT will be as TAB and CONTROL the same as CAPS if you agree in the next release.

[40Crisis]

Hi @40Crisis

This isn't coding this is just MAGIC.

I always thought that porting small games from the gameboy was reasonably feasible on CPC.

I didn't know how and the explanation you give is really magic for my ears.

I have remembered my years with the gameboy with your port and it's exactly the same.

Congratulations!!

P.S. will you release the sourcecode for another people to port other games or do you think on make other ports?

I don't plan to release source code.
Anyway, I believe the emulator was possible because tetris is a simple game with few things displayed.
In my opinion, the CPC is not powerful enough to emulate GB 4,19MHZ processor plus 60Hz display rendering (background tiles 160x144 plus up to 40 8x8 four color sprites).
To give you an idea the emulator ingame (maximum 12 sprites 8x8 are displayed) has a average speed of 25 fps.

[Khomenor]

Ok..
You break the game
My port seems so.... a waste of time...


https://www.facebook.com/redbug/videos/10158439917016668/?t=3

Your port is not a waste of time, You made a port, 40crisis made an emulator
As I said in Oncle_ced's stream I like your port, not the music. Just not my kind of remix 

[Gryzor]

Indeed I love both for different reasons...

[Longshot]

Oups...Better like this to take care of the carry flag...
For swap a (cb 37), rrca/rrca/rrca/rrca/ccf
For swap e (cb 33), rrc e/rrc e/rrc e/rrc e/ccf

In the graphics engine, you can save cpu and code as well.
To calculate the address of the tile

Code Select Expand

19 usec, 10 bytes
        ld h,0
        ld l,a               
        add hl,hl       
        add hl,hl
        add hl,hl
        add hl,hl
        ld a,#80           
        or h
        ld h,aYou can simplify it by doing ld h,8 instead of ld h,0 and deleting ld a,#80...
But you can also do that

Code Select Expand

    15 usec, 10 bytes
    ld hl,bonneteau+1
    ld (hl),a
    ld a,#80
    rld
bonneteau ld l,0
    ld h,a
or this

Code Select Expand

    15 usec, 15 bytes   
    ld h,8
    add a,a
    rl h
    add a,a
    rl h
    add a,a
    rl h
    add a,a
    rl h
    ld l,a
When updating the screen, for each

Code Select Expand

         
         ldi
        ldi
        dec e
        dec e
replace dec e by ld e,b
at the end of one tile, replace

Code Select Expand

         
         exx
        ld d,c
        ld e,b
        inc e
        inc e
        exx


by this

Code Select Expand

       
        exx
        ld d,c
        exx

[40Crisis]

Oups...Better like this to take care of the carry flag...
For swap a (cb 37), rrca/rrca/rrca/rrca/ccf
For swap e (cb 33), rrc e/rrc e/rrc e/rrc e/ccf

In the graphics engine, you can save cpu and code as well.
To calculate the address of the tile

Code Select Expand

23 usec, 10 bytes
        ld h,0
        ld l,a               
        add hl,hl       
        add hl,hl
        add hl,hl
        add hl,hl
        ld a,#80           
        or h
        ld h,aYou can simplify it by doing ld h,8 instead of ld h,0 and deleting ld a,#80...
But you can also do that

Code Select Expand

    15 usec, 10 bytes
    ld hl,bonneteau+1
    ld (hl),a
    ld a,#80
    rld
bonneteau ld l,0
    ld h,a
or this

Code Select Expand

    15 usec, 15 bytes   
    ld h,8
    add a,a
    rl h
    add a,a
    rl h
    add a,a
    rl h
    add a,a
    rl h
    ld l,a
When updating the screen, for each

Code Select Expand

         
         ldi
        ldi
        dec e
        dec e
replace dec e by ld e,b
at the end of one tile, replace

Code Select Expand

         
         exx
        ld d,c
        ld e,b
        inc e
        inc e
        exx


by this

Code Select Expand

       
        exx
        ld d,c
        exx

Master class of z80 programming by Longshot ! Thank you. Optimisations will be included in next update to come

[40Crisis]

New version 1.1
What's new- added gb inlay  + cpc palette and cpc+ palette from totO: many thanks to him
- emulator can be now run in two flavour:run"temu" for cpcrun'temuplus" for cpc+
- some bug fixes and code optimisation thanks to Longshot
- two new keys left shift and left control same as tab and CAPS LOCK suggested by Norecess
- You can edit main palette for cpc and cpc plus in basic loader see line 210 and more

[TotO]

Amazing work!!! 

Here, some WIP theme for CPC if you can't wait.
Just update the BASIC with the colours codes on the top of your floppy drive hardware values.

[40Crisis]

Re: GB TETRIS EMULATOR TEMU FOR AMSTRAD CPC 6128(+)
« Reply #72 on: Today at 18:39 »

    Like
    Quote

If you intend to customize palette, you will need the CPC hardware value:


reference here: https://www.cpcwiki.eu/index.php/CPC_Palette

[vasilisk]

Looks much better on real cpc. Sorry for the poor capture. My phone is not good for video recording 50fps.



https://youtu.be/fFqsJg7eHus