Atari 2600 / VIC 20

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slingshot
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Re: Atari 2600 / VIC 20

Post by slingshot »

Chris23235 wrote: Oh nice! Just tried some other games and they sounded not different (hard to tell if I try to listen for differences I tend to hear them even if they aren't there). But I didn't tried Pitfall!, great news.
I didn't really dig into the inner workings of the module, just shamelessly copied it. It's written by Juha Turunen. I don't think the original was wrong, just it was missing some features.
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Re: Atari 2600 / VIC 20

Post by slingshot »

FrankNStein wrote: Looks like I'll be the first to save anything.
Now you can try again:
https://github.com/mist-devel/mist-bina ... ores/vic20
The ROM file is no longer optional!
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Re: Atari 2600 / VIC 20

Post by DanyPPC »

Well done, Slingshot :cheers:
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Re: Atari 2600 / VIC 20

Post by DanyPPC »

It seems that games with 6000 and 0000 address don't work anymore.

In order Scanlines option don't have effect on YPbPr output, as in the ZX Spectrum Core.

Can anyone test on its MiST ? Thanks
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Re: Atari 2600 / VIC 20

Post by slingshot »

DanyPPC wrote:It seems that games with 6000 and 0000 address don't work anymore.

In order Scanlines option don't have effect on YPbPr output, as in the ZX Spectrum Core.

Can anyone test on its MiST ? Thanks
I can still load two part games, e.g. Defender with $6000 and $a000 parts.
What doesn't work?

Scanlines only work with the scandoubler, you have the choice to have scandoubled or 15kHz output with YPbPr.
Upd.: just tried on my TV, scanlines are OK with component + scandoubler (except it's losing sync with the 75% filter, weird). Actually the previous version of the core doesn't work with component + scandoubler, hence no scanlines.
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Re: Atari 2600 / VIC 20

Post by FrankNStein »

Hi Slingshot,

thank you very, very much!
Not only are you an "Atari God", you're a "Commodore God"! :thumbs: :cheers: :thumbs: :-)
Your new core works super well for me!

Frank
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Re: Atari 2600 / VIC 20

Post by DanyPPC »

slingshot wrote: I can still load two part games, e.g. Defender with $6000 and $a000 parts.
What doesn't work?
Ok, you are right !
I forgot to activate the option for ram expansion.

:oops:
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Re: Atari 2600 / VIC 20

Post by FrankNStein »

Hi to all!

Little question to VIC20 and "real tape":

Do you think it is possible to connect a virtual tape to a MIST/MISTICA after this project (CBM Tape Pi v1.6.1 - https://github.com/RhinoDevel/cbmtapepi)?

"real tape" is supported in this core, right?

Thanks!

Frank
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Re: Atari 2600 / VIC 20

Post by slingshot »

Yes, but TAP files can be played back inside the core, what's the external hardware is good for?
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Re: Atari 2600 / VIC 20

Post by FrankNStein »

Hi Slingshot,

the hardware is usually for "real" VIC20, C64 or PET's. It replaces the datassette.

Did I understand correctly that you can also connect a standard compact cassette player with your core?
I am not (only) interested in virtually loading existing cassette images ("TAPs").
I would like to experiment a little bit with the audio interface of the MISTICA (but NOT with all the disadvantages of the compact cassettes...) - I was thinking more of a WAV-recorder or just this "CBM Tape Pi"...

Frank
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Re: Atari 2600 / VIC 20

Post by slingshot »

You can, but it's only for playback. Tape output is not connected anywhere.
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Re: Atari 2600 / VIC 20

Post by FrankNStein »

Can you explain this to me? - that beats me!
Only for playback? - does that mean I could read WAV through the mic input?
When I switch "Tape Sound: On" I hear the characteristic data sound - can't I record it?

Frank
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Re: Atari 2600 / VIC 20

Post by slingshot »

FrankNStein wrote:Can you explain this to me? - that beats me!
Only for playback? - does that mean I could read WAV through the mic input?
When I switch "Tape Sound: On" I hear the characteristic data sound - can't I record it?

Frank
You can hear the SAVE sound in the speaker? Then you can record it. Maybe I forget how it was done :)

Upd.: yes, it's mixed to the audio output, like on a Speccy. The Commodores have separate tape outputs originally (but no usable pin on MiST for that, the UART TX already occupied by the tape motor control).
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Re: Atari 2600 / VIC 20

Post by MasterOfGizmo »

Uart tx is used for tape motor control? What kind of devices does that need? A real tape would control the motor by the buttons on the cassete drive. There is the motor signal on a real Vic. But is that really needed? I seem to remember that the motor signal was broken on my Vic and this wasn't much of a disadvantage.

But using one of the audio channels is sure a better solution. The channel mixing of the mist may hurt a little bit but chances are that audio output and tape output will not happen at the same time.
MIST board, FPGA based Atari STE and more: https://github.com/mist-devel/mist-board/wiki
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Re: Atari 2600 / VIC 20

Post by slingshot »

MasterOfGizmo wrote:Uart tx is used for tape motor control? What kind of devices does that need?
The 1530 itself. It starts the motor when this signal is active (there's an amplifier in all the C='s to make this signal suitable for controlling the motor). The buttons only activate the sense input line.
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Re: Atari 2600 / VIC 20

Post by Higgy »

Having a ZX Spectrum+ back in the day I did not know anything about the luxury of motor control.
Now owning quite a few systems I see C64, Dragon, MSX had motor control.
I have a MSX tape drive and a Tapduino (digital tape player) which both have motor control inputs.
The CoCo Core (and then hopefully Dragon32/64) will have tape loading input.

On my MiST I removed the resistor(?) on the audio circuit to get more accurate audio separation as per real AMIGA and Sam Coupe.
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Re: Atari 2600 / VIC 20

Post by SegaSnatcher »

Does anyone know if the 2600 core on MiST has a framebuffer? Kevtris swears by a framebuffer when it comes to 2600. I guess its because of 2600 spits out different signal randomly. I'm simplifying things, but basically what 2600 outputs isn't consistent and why a framebuffer helps out.

Edit: Nevermind, this appears to only be needed when outputting to HDMI.
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Re: Atari 2600 / VIC 20

Post by slingshot »

SegaSnatcher wrote:Does anyone know if the 2600 core on MiST has a framebuffer? Kevtris swears by a framebuffer when it comes to 2600. I guess its because of 2600 spits out different signal randomly. I'm simplifying things, but basically what 2600 outputs isn't consistent and why a framebuffer helps out.

Edit: Nevermind, this appears to only be needed when outputting to HDMI.
If you want to render to a framebuffer, and send that to the display, then use an emulator. They do exactly the same.

There are a few games which sends different frame lengths (the number of lines are differ between frames), they'll be shaking in a TV, probably won't display well in every VGA, otherwise no such thing is needed.
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Re: Atari 2600 / VIC 20

Post by nippur72 »

FrankNStein wrote:Do you think it is possible to connect a virtual tape to a MIST/MISTICA after this project (CBM Tape Pi v1.6.1 - https://github.com/RhinoDevel/cbmtapepi)?
yes, you can play and record from real tape using the UART_RX and AUDIO out (on the Mistica: "MIC" for output to tape, "EAR" for input from tape). You need to find the correct volume level, but if the signal is clean it works pretty well. The "motor" pin that drives the tape motor is ignored, and the "sense" pin (for PLAY pressed detection) is emulated when audio is coming from input.

It works the same also on C16 and C64 cores. On the C64 it requires you keep holding the C= key after LOAD, to avoid stopping after the filename is FOUND.
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Re: Atari 2600 / VIC 20

Post by FrankNStein »

@nippur72:

Thanks for your info! Unfortunately, I have not yet had the chance to try it out. (...to much to do...)
CBM Tape Pi isn't a real tape - I hope it works anyway...

Frank
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Re: Atari 2600 / VIC 20

Post by vebxenon »

Just a computer and videogame lover :)

- Atari Jr 2600 clone
- Atari 7800 Peritel
- Atari XEGS
- Atari Lynx II
- Atari Jaguar
- MiST Board
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Re: Atari 2600 / VIC 20

Post by tteclado »

:D gracias Salva
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Re: Atari 2600 / VIC 20

Post by vebxenon »

tteclado wrote: Fri Aug 14, 2020 8:17 pm :D gracias Salva
Bueno... Gracias a Slingshot :D

Well... Thanks to Slingshot :D

- TIA fixes: Playfield mirroring, playfield score flag, (no) collisions in blanks.
- Canyon Bomber, Tutankham, Caverns games are fixed
Just a computer and videogame lover :)

- Atari Jr 2600 clone
- Atari 7800 Peritel
- Atari XEGS
- Atari Lynx II
- Atari Jaguar
- MiST Board
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Re: Atari 2600 / VIC 20

Post by DanyPPC »

New A2600 core update:
https://github.com/mist-devel/mist-bina ... ores/a2600

a2600_200831.rbf

- TIA: fix divider by 6 (E.T., but affects all C,D,E audio waveforms)
- Update the DPC mask flags after changing the counters (Pitfall II)
- TIA: transparent latches for the color registers (D.K.VCS)
- TIA: don't apply pf_score when pf_priority=1 (Bobby is Going Home)
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Re: Atari 2600 / VIC 20

Post by vebxenon »

Just a question, I've tried some modern homebrew games, like Super Cobra Arcade, and core just crashes :shrug: . Do you know what special or strange features uses?

https://atariage.com/forums/topic/27263 ... ra-arcade/

Donkey Kong VCS, for example works very well :D
Just a computer and videogame lover :)

- Atari Jr 2600 clone
- Atari 7800 Peritel
- Atari XEGS
- Atari Lynx II
- Atari Jaguar
- MiST Board
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