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Some experimental videos - for science.

 

Saving on a TI-99/2 and attempting to load on a 99/4A:

 

 

Saving on a TI-99/2 and attempting to load on a CC-40:

 

 

Saving to a Waftertape drive:

 

 

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11 hours ago, acadiel said:

Some experimental videos - for science.

 

Saving on a TI-99/2 and attempting to load on a 99/4A:

 

 

Saving on a TI-99/2 and attempting to load on a CC-40:

 

 

Saving to a Waftertape drive:

 

 

Interesting. All this time I thought the Waftertape drive used those little microcassettes from answering machines. Didn't realize they were something completely different. As an aside, how much data could you save to a microcassette if you could use one to save data?

Edited by Toucan
Added more info

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Toucan,

 Interesting question. I know the cassette save a load commands in4A are pretty well documented, is it is possible to compute the amount that can be saved per minute of type. While saving as many bytes as possible was a goal, from interviews I later did with TI engineers, reliability was probably even more important.

  Also, mildly interesting to anyone playing with cassettes, I'm playing with a machine called a Z88 Cambridge, and have been following the adventures of company - not CCL - that made a cassette interface for the Z88. Two major problems they bumped in to hard was many records had automatic gain control, which after listening for a few seconds would decide to either set the line for blast, or ignore the incoming signal all together. and some of the units didn't have enough power to work reliable.

   The said a good rule of thumb was use a recorded with 3 or 4 batteries, or even better, always leave it plugged in.

  Now, one missing piece, back in the early days or the Huggers Users Group. A lot of cassettes where in play. The hit rate of read back was pretty good as long as it was the same record and tape and was plugged in to the mains (best luck went to GE's Computer Record and TI's own unit). Then it got dicey - with one exception. TI pre-record tapes almost always read back. It would be real neat to pump the person in charge of producing tapes for sale, the quality control they went through to make that happen!

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9 hours ago, Toucan said:

Interesting. All this time I thought the Waftertape drive used those little microcassettes from answering machines. Didn't realize they were something completely different. As an aside, how much data could you save to a microcassette if you could use one to save data?

There were different sizes.  Stay tuned for the documentation @Ksarul and I are providing.  It will state the different lengths and sizes they were going to support.

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On 10/25/2020 at 12:41 AM, Toucan said:

As an aside, how much data could you save to a microcassette if you could use one to save data?

I did it a long time ago with my grandfather's micro-cassette recorder.  It works, and the tapes are metered in minutes the same way as regular-sized cassettes.  As a bonus, his had a remote jack.

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5 hours ago, HOME AUTOMATION said:

Most micro-cassette recorders have 2 speeds.:ponder:

 

And regular cassette players somehow did 600/1200/2400bps on a lot of Japanese computers.  Was this also varying speeds?  Or just different quality heads?

 

15d07bc

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5 hours ago, HOME AUTOMATION said:

Most micro-cassette recorders have 2 speeds.:ponder:

The length of the tape is based upon the 2.4cm/s speed.  So an MC60 is 30 minutes per side at 2.4cm/s, or 60 minutes per side at 1.2cm/s.  The extended play speed worked fine, but on some recorders/players tends to introduce a good amount of wow.  As usual, tape quality has effects, as well.

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36 minutes ago, acadiel said:

 

And regular cassette players somehow did 600/1200/2400bps on a lot of Japanese computers.  Was this also varying speeds?  Or just different quality heads?

 

15d07bc

That is interesting.  A tape should not have trouble with up to 1200bps as that is just FSK. This unit says "phase shift system," which, to me, implies it should, if we are working in the realm of modem audio, faithfully reproduce 2400bps, which is 1200baud with PSK.

 

I have never tried recording a 2400bps session, mostly because most 1200baud modems and up are "smart" and will not transmit without a carrier being present, unlike "dumb" 300baud modems.

 

Now I have to go down the rabbit hole.  ISTR the "Kansas City Standard" originally supported 300bps via FSK, but other manufacturers went their own way with rates like 600 and 1200 from a different standard or proprietary encoding.

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This Japanese computer records at 2400bps on a regular tape recorder. Occasionally fails using old C-60s.

 

The first couple seconds of each save, start at 600 bps and contain the filename and speed setting. When loading, it skips over all saves that don't start with the requested filename, and then it automatically switches to 2400bps if the file was saved at that speed.:grin:

 

model.thumb.JPG.f4267df866a7657bdc6814fe3bedd24d.JPG

 

select.thumb.JPG.37b5f4e2faee7f755c2153a70b03e6f6.JPG

 

right.thumb.JPG.cf73fa69727f2e31aa5f5642f0f1c804.JPG

 

left.thumb.JPG.e3cf69f50ffd8939a65af213afe4f6d0.JPG

 

...also uses a DC to DC converter that can provide all the needed internal voltages from a 12-24vdc supply.:cool:

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25 minutes ago, HOME AUTOMATION said:

This Japanese computer records at 2400bps on a regular tape recorder. Occasionally fails using old C-60s.

 

The first couple seconds of each save, start at 600 bps and contain the filename and speed setting. When loading, it skips over all saves that don't start with the requested filename, and then it automatically switches to 2400bps if the file was saved at that speed.:grin:

 

model.thumb.JPG.f4267df866a7657bdc6814fe3bedd24d.JPG

 

select.thumb.JPG.37b5f4e2faee7f755c2153a70b03e6f6.JPG

 

right.thumb.JPG.cf73fa69727f2e31aa5f5642f0f1c804.JPG

 

left.thumb.JPG.e3cf69f50ffd8939a65af213afe4f6d0.JPG

 

...also uses a DC to DC converter that can provide all the needed internal voltages from a 12-24vdc supply.:cool:

Heh. I just got one of those very computers.  Thats why I went down the rabbit hole of looking at different speed cassette recorders.  The technical manual and cassette format is well documented on several sites.  

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Got my first, on Canal st. NYC '93-'94, $79. But, lost stolen in mid. '94. Got this one a couple years later. It was supposed to interface with the TI, and run a scheduler program. While the TI ran my controller, written in BASIC. But then I started learning assembly language on the TI, and decided it could handle all functions.:grin:

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4 hours ago, acadiel said:

And regular cassette players somehow did 600/1200/2400bps on a lot of Japanese computers.  Was this also varying speeds?  Or just different quality heads?

Same speed, but less reliable at 2400bps.

 

15d07bc

 

I'll bet this unit uses a DC bias, rather than the usual 38k, AC bias. Perhaps, no bias at all.:cool:

Edited by HOME AUTOMATION
include pic.

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1 hour ago, acadiel said:

Heh. I just got one of those very computers.  Thats why I went down the rabbit hole of looking at different speed cassette recorders.  The technical manual and cassette format is well documented on several sites.  

IMG_9803.MOV

I just got your video to play ...had to mirror & flip.

 

Did you get the DEMO cassette with it?

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I just got your video to play ...had to mirror & flip.
 
Did you get the DEMO cassette with it?

Nope, no software unfortunately.

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I have it somewhere but my tape player needs a re-belting, I have belts, but unsure where... I'll try and look into it later. There are a bunch of interesting programs online, made from tapes, but saved as data, rather than audio, I've not been able to figure out how to get them to load. Going back about 10 years there was a partially completed emulator, but I never made sense of it. The site was in Japanese and didn't translate well.

 

I can't remember all the files on the tape, one was about "catching stars", had graphics of buildings scrolling sideways, and a figure of a kid on a swing, set to music.:)

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On 10/25/2020 at 10:38 AM, acadiel said:

There were different sizes.  Stay tuned for the documentation @Ksarul and I are providing.  It will state the different lengths and sizes they were going to support.

Here are three different sizes.

 

Wafertape-Sizes.jpg

Edited by iliketurtles
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