Idea - Tape Deck Emulator / SD-Card

This is the right place to discuss on how to implement hardware vsync, adding a VIA or AY chipset, puting multiple roms, or how to design a new flash expansion card.
Torlus
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Idea - Tape Deck Emulator / SD-Card

Post by Torlus »

I had an idea this morning (well, to be honest I somewhat "stoled" it from DBug during an IRC chat session ;)) : build a Tape Deck Emulator (TDE for short) based on a microcontroller (MCU).
Basically, the MCU would be connected to Oric's tape connector, and read .TAP files from a SD-Card, and would perform on-the-fly what Tap2Wav does.

For file selection, a LCD panel and a few buttons could do the job, but I have a better idea : a special program (stored on the SD-Card with a specific name, like MENU.TAP) would implement a simple protocol with the TDE, using only Tape in/Tape out for communication.
It would be able to retreive the directory listing of the SD-Card, and then select a given .TAP for loading.

Pros :
- It would allow to use most existing Oric software. Correct me if I'm wrong but I think that most software came in a cassette format.
- The design will be quite simple, so it's a project that may see the light of the day in months, not years.
- The TDE would be cheap and easy to build : only a MCU, a few connectors and some passive components.

Cons :
- Loading times, of course.

Bonus :
- The firmware of the MCU could be stored on the SD-Card itself (the MCU being only flashed with a bootloader program), allowing easy firmware upgrades.
- This idea could be extended to other platforms than the Oric.

Any comments are welcome.
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Symoon
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Post by Symoon »

Had this idea long ago, seems perfectly doable.
My idea was to send commands to the PC using CSAVE. For instance, if you want to see the PC directory content, type: CSAVE"DIR":CLOAD"".
The pc would recieve the CSAVE signal, analyse the command, perform it on PC, do a file with it, make a WAV file and send it to the Oric at the screen address.

The goal was to be able to have a link between Oric and PC without any special hardware.

Sadly the lack of reliability (and loads of other Oric things in the works) discouraged me. I tested about 8 PC/Oric combinations, only one seemed to work almost flawlessly. So far all my PC program did was to decode on the fly a letter sent by the Oric thru the tape port.

EDIT: just want to add that I have absolutely no knowledge in hardware things, so maybe there's an easy solution to improve the audio link, I don't know.

After all, I don't think it's worth the effort if the goal is just to load existing programs. Just select the file on PC or on a mp3 player and that's it. The only goal of such a link would be to give access to the Oric to PC possibilities (Internet communication, mega storage for a big graphic adventure game...).
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ibisum
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Post by ibisum »

I have the same idea except that its a disk emulator and just works as a virtual drive - select the DSK file on the external adapter, oila: your Oric sees a new disk inserted.

Working on it. Slowly.
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Chema
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Post by Chema »

I would not like to seem as if repeating myself, but here it goes.

Any small and compact mass storage is appreciated indeed. The loading times could be made smaller if Fabrice's quick loading patch is applied (never tried it, but it seemed to work when loading from CDs and PC?). I know that plugging to a PC has its risks (and you need the PC near, of course) and most MP3 just don't work.

So I see the pros of such a system.

But what would be indeed interesting is emulating the microdisc controller adding SD support or even plugging a real drive. Those controllers are not cheap, easy to find nor reliable. And there are diagrams out there, people from CEO built them, etc...

But that would be more expensive and difficult to do, I know... :(
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Symoon
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Post by Symoon »

Chema wrote:The loading times could be made smaller if Fabrice's quick loading patch is applied (never tried it, but it seemed to work when loading from CDs and PC?).
I used it several times from PC, but I wonder if Fabrice didn't have problems with CDs.
It's really impressive loading a program in a few seconds.
A few drawbacks: will only work on Atmos, and a few programs won't work with the very fast speed.
and most MP3 just don't work.
True that finding the correct settings is not easy. The question is: why? Will it be better with another piece of hardware, since this might be due to the Orics?
But what would be indeed interesting is emulating the microdisc controller adding SD
Oh yes this is the big challenge ;-)
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Post by Godzil »

Symoon wrote:
Chema wrote:The loading times could be made smaller if Fabrice's quick loading patch is applied (never tried it, but it seemed to work when loading from CDs and PC?).
I used it several times from PC, but I wonder if Fabrice didn't have problems with CDs.
It's really impressive loading a program in a few seconds.
A few drawbacks: will only work on Atmos, and a few programs won't work with the very fast speed.
and most MP3 just don't work.
True that finding the correct settings is not easy. The question is: why? Will it be better with another piece of hardware, since this might be due to the Orics?
Funny to see that other people have the same idea as me ;)

Anyway, I have some discovery board from ST (STM32 based) they don't, they are really cheap MCU based on Cortex M3 and could make a easy start for such a device.

The board does not have a SD socket, but using SPI only coast 4 wires and the board have plenty of GPIOs. This could be fun to do it on them.
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Post by Godzil »

So,

I'm planning this project, using the STM32VL Discovery board, a SD card, for now a simple 2 line LCD Text Screen (the same I have for the HxC).

I may downgrade, or change the µP version after the prototyping, this one may be a bit too much for this (anyway, it's really cheap, so)

What is planned for the prototype:

- browsing the SD card for TAP file (I doubt be able to use WAV file, we will see later) and folder support!!!
- Using Slow (1200), Normal (2400) and Highspeed transfer mode (the High speed will be the fabrice version) using option menu.
- Beeing able to play/pause the vtape (virtual tape)
- Seeking (FastForward/FastRewind, ...) the vtape
- Beeing able to take acount of the tape pause/stop relay

The "final" version should have too:
- Browsing the SD card from the oric
- Audio passthrough ? (ie having a jack/RCA output for the audio output on the DIN
- Tape Audio in/out for real external tape using jack/rca connector ?
- Directly play waves ?
- Make Fabrice HighSpeed mode work on a Oric 1?
- Beeing able to directly record to tap file
- Using a nice graphical screen instead of a text screen ? (I have an idea for the device package :D)
- Bug free! ;)

- Not directly Oric oriented, but such a project could interest too other tape enabled computers, so it could support other vtap format.
Please feel free to comment the specs for the "final" version, if something seems not usefull for you, or something that is really missing ;)

The thing I'm usure is about tuning the output voltage, like the volume button of a tape player will do. I will prefere a fixed value, but the Oric (1 and Atmos) is such a shy guy that even with normalized level, it can be unable to load a tape with correct output levels...

I'm usure about how the project will be release, as full open source, or something like for the SD HxC (Even if it's simpler than the HxC, it will be a non trivial project, and I unsure to want to see my work stolen ;))


I will make a real topic for this project when it will more than a few line of text in a forum ;)
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Post by highwayman »

http://www.luigidifraia.com/c64/dc2n/index.html

this was an open project until recently! :cry:
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Post by coco.oric »

Good idea, i will be a good customer.
Bravo
coco.oric as DidierV, CEO Member
Historic owner of Oric, Apple II, Atari ST, Amiga
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