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c64 datasette support

Posted: Tue Jan 04, 2011 4:53 pm
by chunky_tesco
probably a very long shot, but is there any remote possibility to some how connect a c64 datasette via an adapter to dump tape images?

I used the c64s and MTAP with a PC via parallel port but the PC has been bombed now

apologies if the request is completely unfeasible :)

Re: c64 datasette support

Posted: Tue Jan 04, 2011 6:03 pm
by tect
Hi,

isn't it much simpler to "dump" C64-tapes with a normal cassette recorder and a sound card? ;)

Re: c64 datasette support

Posted: Tue Jan 04, 2011 6:12 pm
by IFW
Yes, it should be possible as long as you have a single digital input line that you want to continuously sample - but this would require quite some software development.

Re: c64 datasette support

Posted: Tue Jan 04, 2011 7:35 pm
by chunky_tesco
normal cassette recorder & sound card is notoriously unreliable according to Markus Brenner (http://markus.brenner.de)

The website also has the MTAP/PTAP dumping software source code. I would have thought the biggest challenge is connecting a datasette to the Kryoflux board

Re: c64 datasette support

Posted: Tue Jan 04, 2011 9:06 pm
by IFW
I guesss you'd want to connect some sort of read line and maybe play button or if there is a signal for end of tape... should be fewer signals than a drive I guess..

Re: c64 datasette support

Posted: Wed Jan 05, 2011 12:01 am
by chunky_tesco
A read line and a write line? MTAP reads the tape, and PTAP writes back.

from what i remember at command line it goes something like
? mtap filename.tap
Press play on tape
reading...
...
...
...
Tape stopped...
filename.tap saved

Re: c64 datasette support

Posted: Wed Jan 05, 2011 11:55 am
by mr.vince
The KryoFlux is a flux sampler. It measures the signal presented on the data line and sends it over to the host.

I have never looked at the levels presented by the datasette, but afaik it's a pretty cheap A/D converter made with some schmitt triggers or the like... Or the triggers are on the cassette port of the C64. Aynway, I assume the logic works with 5V max, which is also the max. the KryoFlux board is working with.

Ultimately, it should be possible to build an adapter cable and a firmware that deals with this and use KryoFlux as a tape sampling device, however, it's not our main target at the moment...

Re: c64 datasette support

Posted: Wed Jan 12, 2011 2:20 pm
by OCMoe
Trouble is, cassette formats vary more at the physical level than disk signals. The C64 Datasette includes a Amplification/Schmitt-Triggerning circuit that detects zero-crossings, while other systems usually use plain (analog) audio and do various things in the computer itself. On top of that physical layer, you then get FM/MFM/etc. coding as with floppy disks.

http://www.zimmers.net/anonftp/pub/cbm/ ... 2N232.html is an interesting solution if the C64 datasette interface is all you need, as it works on the already-schmitt-triggered level.

Re: c64 datasette support

Posted: Wed Jan 12, 2011 10:58 pm
by Specfreak
Hi Guys,

Just got my Kryoflux board today and wondered a similar thing. I have a Shuttle PC that can boot into DoS and a small 4GB partition for use with MTAP to dump C64
tapes from my C2N Data Cassette using the adaptor. I've dumped hundreds of tapes in the past, but not in the last few years. We hosted what we dumped over
at the .TZX Vault (http://www.tzxvault.org/C64/index.htm) and also did VIC-20, C16/+4. However these tapes weren't cleaned. At the time we envisaged converting
the TAPs into TZX which we also have hundreds of but that didn't really take off. We then provided dumps for the Ultimate C64 (http://tapes.c64.no/index.php)
folk who were more geared up and knowledgeable with C64 tapes, though no updates have been done since 2007.
Later another site came to be (http://c64tapes.org/).

Anyway, enough of my ramblings..... with the lack of Parallel ports it would be cool to be able to dump in more modern environments, though I'm not sure what remains to be dumped.
Maybe someone will develop an adaptor some day.

Yer Markus didn't like WAV/VOC -> C64 RAW-TAP conversions which is why we ended up buying the C64 adaptor. It's still nice to replay a C64 TZX in TAPIR though, or indirectly in VICE which hooks
into 64TZXTAP to convert before loading.

I just love dumping tapes and disks for most 8-bit comps etc.

Re: c64 datasette support

Posted: Mon Jan 17, 2011 12:38 am
by Specfreak
@op

I just remembered about the DC2N thing:
http://www.luigidifraia.com/c64/dc2n/index.html

Might be of interest for those without a parallel port.