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GeneralRe: Yesterday I was slightly embarassed Pin
Slacker00722-Jan-17 12:00
professionalSlacker00722-Jan-17 12:00 
GeneralRe: Yesterday I was slightly embarassed Pin
lopatir22-Jan-17 5:29
lopatir22-Jan-17 5:29 
GeneralRe: Yesterday I was slightly embarassed Pin
ZurdoDev23-Jan-17 1:15
professionalZurdoDev23-Jan-17 1:15 
GeneralSuc(c)ess! Pin
CDP180221-Jan-17 9:53
CDP180221-Jan-17 9:53 
GeneralRe: Sucess! Pin
Mike Hankey21-Jan-17 11:01
mveMike Hankey21-Jan-17 11:01 
GeneralRe: Success! Pin
Brisingr Aerowing21-Jan-17 11:40
professionalBrisingr Aerowing21-Jan-17 11:40 
GeneralRe: Success! Pin
Nighthowler22-Jan-17 0:45
Nighthowler22-Jan-17 0:45 
GeneralHow old can a bit on magnetic tape get PinPopular
CDP180220-Jan-17 12:05
CDP180220-Jan-17 12:05 
... and still be read? My tapes for the old Elf II computer are 35+ years old and 20 years ago I have been told that they will not load anymore. Most still did, but I thought it would be great to find a way to load them with a PC and possibly reconstructing those that can't be loaded normally anymore.

Long ago I wrote a Win32 program in C++ that could load the tapes (sampled as WAV files) and then reconstruct the binary file. The real pain was to figure out the correct timing values for each particular recording.

Now I'm working on a new .Net version that supports the tape formats of similar computers, figures out the timing automatically and lets you manually edit 'bad' bits when nothing else helps. It's not finished yet, but it already as far as building a stream of bits and allows to edit them. Only the last step, taking the start bits, data bits and parity bits and converting them to bytes is still missing. Then I can save a simple binary file.

Here is the beginning of a good sample[^] The blue '1' to the left are the end of the leading beep' on the tape, followed by the first start and data bits in green.

Now look at this one.[^] The input signal is much weaker and I'm amazed how much he (self invented) algorithm still can read from it. There are two bits with invalid timing, both probably '1'. I could simply click on them to override their values, clean up all further errors (there are buttons to navigate to them at the top), and then this file can be rescued from east hyperspace.

Somewhere on these tapes are my first working machine code programs and I will not rest until I have recovered them all.

Edit: It's not a bug, it's a feature! In the old program I had to figure out the number of samples that make up a long or short pulse manually. That's why the WAV files had to be sampled with a specific sample frequency. The new program analyzes the samples and figures out the timing automatically. The sampling frequency has become unimportant. I just converted some oder WAVs which were sampled at a lower frequency without problems!
The language is JavaScript. that of Mordor, which I will not utter here

This is Javascript. If you put big wheels and a racing stripe on a golf cart, it's still a f***ing golf cart.

"I don't know, extraterrestrial?"
"You mean like from space?"
"No, from Canada."

If software development were a circus, we would all be the clowns.


modified 20-Jan-17 19:31pm.

GeneralRe: How old can a bit on magnetic tape get Pin
PIEBALDconsult20-Jan-17 12:26
mvePIEBALDconsult20-Jan-17 12:26 
GeneralRe: How old can a bit on magnetic tape get Pin
CDP180220-Jan-17 12:34
CDP180220-Jan-17 12:34 
JokeRe: How old can a bit on magnetic tape get Pin
DaveAuld20-Jan-17 18:20
professionalDaveAuld20-Jan-17 18:20 
GeneralRe: How old can a bit on magnetic tape get Pin
CDP180220-Jan-17 19:41
CDP180220-Jan-17 19:41 
GeneralRe: How old can a bit on magnetic tape get Pin
kmoorevs21-Jan-17 6:30
kmoorevs21-Jan-17 6:30 
GeneralRe: How old can a bit on magnetic tape get Pin
Marc Clifton21-Jan-17 3:29
mvaMarc Clifton21-Jan-17 3:29 
GeneralRe: How old can a bit on magnetic tape get Pin
CDP180223-Jan-17 3:55
CDP180223-Jan-17 3:55 
GeneralRe: How old can a bit on magnetic tape get Pin
theoldfool21-Jan-17 4:43
professionaltheoldfool21-Jan-17 4:43 
GeneralRe: How old can a bit on magnetic tape get Pin
jamesperrett22-Jan-17 22:58
professionaljamesperrett22-Jan-17 22:58 
GeneralRe: How old can a bit on magnetic tape get Pin
Kirk 1038982123-Jan-17 3:44
Kirk 1038982123-Jan-17 3:44 
GeneralRe: How old can a bit on magnetic tape get Pin
CDP180223-Jan-17 3:52
CDP180223-Jan-17 3:52 
GeneralTech question - Google youtube API - Quota - How is it count? Pin
Mike (Prof. Chuck)20-Jan-17 7:27
professionalMike (Prof. Chuck)20-Jan-17 7:27 
GeneralRe: Tech question - Google youtube API - Quota - How is it count? Pin
Dave Kreskowiak20-Jan-17 7:39
mveDave Kreskowiak20-Jan-17 7:39 
GeneralRe: Tech question - Google youtube API - Quota - How is it count? Pin
Mike (Prof. Chuck)20-Jan-17 7:43
professionalMike (Prof. Chuck)20-Jan-17 7:43 
GeneralRe: Tech question - Google youtube API - Quota - How is it count? Pin
Dave Kreskowiak20-Jan-17 7:46
mveDave Kreskowiak20-Jan-17 7:46 
GeneralRe: Tech question - Google youtube API - Quota - How is it count? Pin
Mike (Prof. Chuck)20-Jan-17 8:06
professionalMike (Prof. Chuck)20-Jan-17 8:06 
GeneralRe: Tech question - Google youtube API - Quota - How is it count? Pin
Dave Kreskowiak20-Jan-17 8:15
mveDave Kreskowiak20-Jan-17 8:15 

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