MIST C64 core

[DrOG]

Hi all!

Some progress here!

With latest 'pre-release' core (20190428) I was able to load programs from .wav file, switching on the 'inverted waveform' option of the wav-prg during generation. It says ?LOAD ERROR, but listing the file right after loading it seems to be intact. (My test file was a short BASIC program which calculates the volume and surface of a cuboid). But after running and listing again it does not function anymore.

I had success with saving another short basic program via audio out, but I was unable to reload it, the problem may be the too low signal level (my Pioneer CT-S310 deck's VU meter shows -6dB, it's about the half of the scale and the theoretical maximum). It would be nice to boost up the tape output's volume...

I made some photos and attached them as illustration.

Thanks again to everyone who is participating in this project!

Regards: Gábor

[Maliniak]

Hi everyone!.
Thank you very much for adding TAP support to the C64 core!

I was able to use the MIDI IN port to load the tape. It works very well.
I even use a real C2N 1530 to load the tape in MIST.
Here everything works very well, in addition to stopping the tape at the header.
If you could add MOTOR signal support to control the TX_FPGA pin motor, that would be fine.
In the "V6Z80P tape adapter" diagram, the TX lines can be connected to 3.3V, then the TX line will be free for the MOTOR signal.

[Maliniak]

Hi everyone!.
Thank you very much for adding TAP support to the C64 core!

I was able to use the MIDI IN port to load the tape. It works very well.
I even use a real C2N 1530 to load the tape in MIST.
Here everything works very well, in addition to stopping the tape at the header.
If you could add MOTOR signal support to control the TX_FPGA pin motor, that would be fine.
In the "V6Z80P tape adapter" diagram, the TX lines can be connected to 3.3V, then the TX line will be free for the MOTOR signal.

[slingshot]

In the "V6Z80P tape adapter" diagram, the TX lines can be connected to 3.3V, then the TX line will be free for the MOTOR signal.

Even if you don't change the adapter, it should work. You don't need the input data when the motor doesn't run

[DrOG]

Further progress...

I found the reason of the LOAD ERRORs: it was the AVPlayer I used... The one marked with red on attachment #1 is not good for the C64 core, although works perfectly with Spectrum and Amstrad cores.
The another one, marked with blue works well with C64 core, even in cases the wav-prg is set to triangle or sine waveform (try attachment #2) ... I was able to load the inverted waveform buckrogers (attachment #3) as well without load error, but after the ALFIE the core resets, as nippur72 wrote earlier. It' strange, as the .prg (attached on the previous page of this topic) runs fine on the same core. The reason is perhaps that the next screens shows a loader, and it may interfere with the current tape handling.

Regards: Gábor

[slingshot]

Meanwhile I found out that UART_TX is always low, so if you're using it for pulling up TX, it hardly works. It doesn't affect Mistica, since the pullup is connected to 3.3V.
I already added output current motor control state to UART_TX in git (but hope nobody wants to connect directly a 1530 datasette motor to it, it'll overload the FPGA).

[DrOG]

Thanks for your continuous efforts!
Question to Android phone users: which app do you use to playback .wavs? It would be much easier to use my 'new' phone as the old jailbroken iPhone...

[slingshot]

Why using a smartphone for playing wavs? They can play directly TAPs, too, no need for conversion.

[nippur72]

@DrOg: I can't see why it should work on the Spectrum and not on the C64 ... Anyway have you tried the volume test I proposed in this message ?

[DrOG]

@slingshot:
You're right, I cannot say a good reason... But why not?

@nippur72:
Didn't try it until now, but I'm going to test the file during this weekend as the VIC20 core has now .tap (and I assume .wav) support. I suppose my biggest problem is the too low volume of my Chinese smartphone, but it seems that different applications playback audio files different ways... weird.

[slingshot]

@slingshot:
You're right, I cannot say a good reason... But why not?

I just thought you can have a collection of TAPs, TZXes and CDTs then without converting them all.

[Maliniak]

I already added output current motor control state to UART_TX in git (but hope nobody wants to connect directly a 1530 datasette motor to it, it'll overload the FPGA).

thank you very much for adding the motor signal.
Now the cassette stops at the header and after loading.
There is only a problem with rewinding the cassette because when the mist does not receive data on the rx line, the motor is standing and the cassette can not be scrolled. But it must be so.You can also enter the menu and press "Play / Stop tape" to start motor and rewind the cassette.
I used an opto-isolator and BC327 transistor to control the motor from TX .
5V power supply can be taken from usb mist.
The c2n tape draws a maximum current of 200mA.

[slingshot]

Yes, the play/stop option can be used for signalling the rewind button press. Maybe a real rewind can be added (effective for TAP files), but I'm lazy for that

[Julitium]

Hi.
I'm continue amazed at the result achieved with the C64 core and its tape loading ... it's great.
I have detected a game that detects something strange. the load is correct but starts locked.

the game is ENLIGHTMENT DRUID II 1987 (Firebird).
All others fine.

Thank you very much for this impressive and exact core C64.

[vebxenon]

Just one thing . If you want to play for example Space Harrier II, you need to load default kernal, using Jiffydos, enemy graphics are not displayed

[Lroby74]

Just one thing . If you want to play for example Space Harrier II, you need to load default kernal, using Jiffydos, enemy graphics are not displayed

I don't use Jiffydos almost anymore, i start with original kernal and then load Action Replay 6.0 or above cartridge and use his fastload, it's twice faster than Jiffydos and don't block TAP loading

[bertnorg]

i'm just curious, not asking for anything.
and i do realize that it is not logical.
i'm exploring some options to connect a 1581/1541 disk drive.

has anyone explored something like this.
there are still new games coming out on 5,25 disks

[slingshot]

The IEC serial port needs at least 3 pins, but there's only 2 general purpose IO pins to the outside world on MiST. Maybe with a multiplexing hardware interface, it would be possible.

[bertnorg]

i'm exploring some options like zoomfloppy or xu1541, they are connected via usb
has anyone explored something like this.

[Televicious]

8580 on this in mono or stereo seems to have issues with the noise wave form. Not getting noise sound from it in SIDwiz. 6581 noise works perfect.

So I was playing with it more and found that noise waveform does kick in eventually, but it's kinda totally random as to when. Sometimes it takes several minutes. Also, backtracked and found that was the same issue with the Feb 2019 version all the way up to the most recent with tape drive support and sounds. So my guess is it's in the 8580 code itself.

[rittwage]

The 6581 seems to be "tinny" and lacks low-end, whicht the 8580 seems normal.

[DanyPPC]

On latest core release 2 button joystick works well on Robocop2, Chase HQ2 but not in new Super Mario Bros.

[slingshot]

Here's a new release:
https://github.com/mist-devel/mist-bina ... res/fpga64

This time with some VIC-II fixes, too, some demos work (better). I wonder if there are regressions.
Also the C64.ROM is mandatory now, Kernal and Basic are no more built-in.

[DrOG]

Thanks!

[vebxenon]

Here's a new release:
https://github.com/mist-devel/mist-bina ... res/fpga64

This time with some VIC-II fixes, too, some demos work (better). I wonder if there are regressions.
Also the C64.ROM is mandatory now, Kernal and Basic are no more built-in.

Thanks very much!