[Coco] Old cassette tapes

[Allen Huffman]

> On Apr 27, 2020, at 5:59 AM, Luis Oliveira <lfl.tr at soeiro.com.br> wrote:
> What bitrate did you use? 441.1KHz at 16 bits?

I started at 44KHz and then did some at 96KHz. Way overkill considering the low frequencies of the tape tones, but I thought it wouldn’t hurt to capture more data. Maybe we don’t have a tool to do anything useful with them today, but maybe ten years down the line some AI audio tool exists (like they are doing with video upscaling) that would recover more.

> Good idea! After capturing, how did you merge the two tracks back into one for 
> a mono signal? Did you use any filters?

I did not. But I have the data if I need to. I had some files that would not load, but I had made multiple saves on most tapes, so I got everything I was after (except for one jammed tape).

But, yeah, I’d consider trying turning it to mono. Probably some filters too that might help.

I do know that some of the things I had trouble loading, I was able to send the .wav file to a Commodore guy and he was able to recover more of my files.

On the CoCo, those of us that did not use a real computer tape recorder (which usually had auto-level control disabled) may have more problems. My cheap K-Mart or whatever tape recorder did auto-level, so my CoCo tapes would be loud-soft-louder at the start.  That is something Audacity could probably compensate for.

I also saved alot of my tapes out at double speed (POKE 65395,0) so they would load faster. I’ll have to do what you are doing and see what’s on my box of CoCo tapes when I find them. I may have problems with my double  speed ones :)

		— Allen