simple //e cassette problem

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simple //e cassette problem

First post!  So I'm sure I'm gonna break a bunch of rules!  :^)  I did search the forum for this question before posting!

 

This is my first foray into the // world.  I got a new-to-me //e.  I installed a ReActiveMicro PSU before even turning it on.

 

It didn't come with any DOS disks.  I've ordered some on eBay.  But in the meantime I tried writing a few lines of basic and SAVE'ing them to cassette.

 

I can't get the data to LOAD back into the computer.  Once the header tone starts, the computer says "ERR" and the cursor just sits on that line after the second R.

 

I can hear the SAVEd data on the cassette, but with the volume cranked there is so much "white noise" I can understand how a computer might not be able to hear it.  It was so bad I thought that perhaps the MIC was also recoridng at the same time, but I tried SAVE'ing while saying, "test test" and confirmed that the MIC wasn't recording.

 

So perhaps its a crappy cassette recorder.  It was 50 bucks on Amazon.  I've ordered an old "GE Computer Program Data Cassette Recorder" so we'll see if that helps.

 

I did plug a set of ear buds into the //'s audio out port and typed SAVE.  I can hear the data coming from the port but BARELY.  There is no volume knob of course, but maybe there is a problem somewhere causing the "volume" to be low.

 

Can anyone tell me if the SAVE sound from your audio out port is very faint?  Or if you have any other suggestions?

 

Not having tape access wouldn't be the end of the world, but I can't just let the problem sit there without trying to fix it!  :^)

 

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A hint on diagnosing cassette save / load problems

A proven method to speed up diagnosing any problem is to split it in half. And then when one half turned out to be OK the other one becomes the suspect and again is split in half to investigate.

 

In your case, dcrowell, do the split between the cassette recorder and the Apple IIe. This means: remove the cassette recorder for a while and try to work with the audio input / output of any notebook computer etc.  Use appropriate software to record the audio from TAPE OUT (going to the MICrophone inputs) and to play back via the SPEAKER/HEADPHONE output. You can use the free software AUDACITY. This allows you to "see" the waveforms and to edit them, i.e. scaling them up or down.

 

The catch is that the Apple IIe has MONO jacks while the PC world (and all media players) have STEREO jacks nowadays. You need to make STEREO cables with the right channel (the "Ring" on the plug) being disconnected. Only the "Tip" and the ground (on the stem of the plug) must be connected.

 

The best and cheapest way to make such special cables is to just remove the outer insulation of an old STEREO audio cable with 3.5mm plugs on each side, and then find out which of the two inner conductors (other than the shield mesh = ground) is connected to the "Ring". You can probe that by sticking a fine needle trhough the insulation, and then measure the needle vs. the tip of either plug by means of an ohmmeter. Then cut the one inner conductor which is connected to the "ring". This opens the circuit for the right channel. You now have one audio cable which is safe to use with the Apple IIe and any PC audio port. One such cable is enough to experiment.

 

If you have some 3.5mm MONO plugs around, you can cut the STEREO cable in half and then mount a MONO plug on the cut end. Do not connect the conductor which goes to the "Ring". You now have got two audio cables suitable for the Apple II.

 

Do not use MONO audio cables (or MONO plugs) on the SPEAKER/HEADPHONE output of a sound card or media player. This will short circuit the right channel to ground. Not good. It could damage the sound card or media player. This is why special cables must be built as described above.

 

Here is a photo explaining what is "Tip", "Ring", etc.:

 

 

It should be obvious from the above photo why a MONO plug will short circuit the right channel to ground when inserted in a STEREO jack. And why a STEREO plug inserted in a MONO jack also will get the same short circuit. So, even with the special cables, the MONO plug always plugs into the Apple IIe.

 

Once you are able to SAVE and LOAD your BASIC programs with this rig, you can then investigate what is wrong with the cassette recorder.

 

Any recording should sound crisp - listen to the SAVED recording made with the sound card. It is a high pitched noise that sound almost as shattering glass. If the playback from the cassette is dull, the electrolytic capacitors in the cassette recorder may be the culprit and should be replaced.

 

Tell us what you find by posting here. These experience reports are helpful for other newbies in the Apple II world.

 

- Uncle Bernie

 

 

 

 

 

 

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Holy smokes, thank you for

Holy smokes, thank you for the detailed reply.

 

Solving this audio/data problem is actually "half" of the "ADTPro boot via audio" problem.

 

Can you tell me if a 15-foot cable would cause significant enough signal loss to cause a problem here?  I'm hoping I can use a long cable so I don't have to relocate either computer.

 

Thanks again, I will give this a try!

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In post #3, 'dcrowell' wrote:

In post #3, 'dcrowell' wrote:

 

" Can you tell me if a 15-foot cable would cause significant enough signal loss to cause a problem here ? "

 

Uncle Bernie answers:

 

Like many things in the real world, the answer is "it depends".

 

A 15 ft audio cable will not cause enough signal loss to matter. But what could happen is that you may get a ground loop (it would manifest has a hum) or, if the quality of the shielding in the audio cable is poor, it may act as an antenna to pick up all sorts of radio frequency interference, and any PN junction at the end of the cable will demodulate that to complete your primitive, but unwanted, radio receiver. Since you plug the cable in semiconductor based devices, there will be such PN junctions. If you have that effect, you can try to mitigate it by winding a few turns of the cable around a large ferrite ring.

 

So with the long cables you open yet another can of worms. It may be easier to move the Apple IIe near the signal source, at least for experimenting. Just put the Apple IIe on the floor near the other computer running AUDACITY. This is what I would do.

 

But if for some strange reason you need this 15 ft cable setup as a permanet installment, be warned that high quality audio cables are heinously expensive. The cheap Chinese made audio cables have a very cr@ppy shield, it's not a woven mesh, but just a few strands of naked wires running along the inner conductors, and they obviously hope that with the inner twist of the cable this makes a shield - which is a fallacy.  The cheapest solution against the RF interferers on long audio cables is to buy real 50 Ohm or 75 Ohm coax cables the type used for video applications - but again, be warned, the crafty Chinese also make lousy video cables. But all coax cables from reputable manufacturers have a fine, woven mesh as an electrostratic shield (the cheaper ones from reputable manufacturers have a wrapped aluminum foil as a shield, but that also works fine until you try to connect it to a plug - some tricks are required, such as tightly wrapping bare copper wire around it to make good all-around contact with the aluminum foil).

 

Do not worry about the "50 Ohms" or "75 Ohms" - it's the characteristic impedance of these coax cables and not the ohmic resistance. So there will be no signal loss for audio applications either.

 

- Uncle Bernie

 

 

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dcrowell wrote:...Can you
dcrowell wrote:

...

Can you tell me if a 15-foot cable would cause significant enough signal loss to cause a problem here?  I'm hoping I can use a long cable so I don't have to relocate either computer.

...

 

You can use https://asciiexpress.net/ from your smartphone/tablet/laptop to test your cable and figure out how loud the volume needs to be in order to load successfully.

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UncleBernie wrote:A proven
UncleBernie wrote:

A proven method to speed up diagnosing any problem is to split it in half. And then when one half turned out to be OK the other one becomes the suspect and again is split in half to investigate.

 

In your case, dcrowell, do the split between the cassette recorder and the Apple IIe. This means: remove the cassette recorder for a while and try to work with the audio input / outpu

One addition (and maybe clarification) to Uncle Bernie's comment about the "ring" conector on a "stereo" 1/8" (3.5mm) cable is you don't need to modify anyting on the cable. Just make sure if you're using a PC/cell phone that audio sent on the left channel. As long as you use a cable from the //e to cassette recorder or PC you should be fine because //e deals with the tip only.  The sleve is connect at the entry to the jack, not at some pont along the interior so you should not need to modify a cable, the ring is just ignored as it alwasy has been with mono jacks when matched with stere plug.

 

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Welcome to the II world! You

Welcome to the II world! You got off to a good start with the new supply that's a great first step!!

 

You mentioned the audio is low on the cassette, is that when played back though the cassette deck or are you playing the audio out through some other device? What are you using to save/play cassettes? 

 

Cassette input is a line-level input which means it's an unamplified level. Do you have a scope? Can you check the levels on the audio jacks? If so the audio level should be nsar -2/2V range both in an out. 

 

When you see ERR, there are generally two causes: audio level (too low level, or saturated), or RAM. Are you sure your RAM is good?Do you have access to a PC with audio out? Have you tried using asciiexpress.net to load a program? Those images all include a disk writer, but if you can load the disk writer that would be a good test. 

I found this works best with andriod devices with 1/8" audio jack. Make sure the audio output has all sound processing disabled, this means things like dolby headphone, equalization, bass boost, ear protection, etc. Volume out somewhere around 90%. Again, if you have a scope, the handshake should be ~4VPP  and program load should be close to 2VPP.  The other thing to know about asciiexpress is there are several different version generall "lo-fi" and "hi-fi" I've found one works, the other doesn't and that's based on the computer and sometimes lo-fi works, other times hi-fi works! (it's confusing)

 

You may want to start with a RAM check, but at this point there are only two options for that. The first is the internal System Test. Hold down the right apple key when powering on should run the system check. You hope to get a Kernel OK message. If you get a RAM error that would need to get addressed.  

 

The other option for testing memory is low-level and if we don't need to go there, we shouldn't because that's a step into the deep end of Apple work in the II Monitor (monitor is machine code interface not the thing used for viewing).

 

As our Uncle said, 15' cable an issue? That's always questionable given most cables are crap, it's totally possible your cable could be bad. Have you tried recroding from a source other than the II? Attenuation with a 15' cable should be very small, but greater with lower quality cables and it doesn't take much to bring the input level too low. Again a scope would be best to confirm what the level the Apple IIs sees.  Have you treid a contact cleaner on the  cassette ports? This is tricky so may not be something for a novice. Are there any signs of rust around the ports or anywhere on the board?

 

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In post #6, 'Jeff D' wrote:

In post #6, 'Jeff D' wrote:

 

" One addition (and maybe clarification) to Uncle Bernie's comment about the "ring" conector on a "stereo" 1/8" (3.5mm) cable is you don't need to modify anyting on the cable. Just make sure if you're using a PC/cell phone that audio sent on the left channel. "

 

Uncle Bernie warns:

 

Follow the advice of 'Jeff D' at your own peril. You can always buy a new media player once you have fried the right channel output amplifier, which would help the stuttering economy by increasing GDP. (Among economists, it's called the 'broken window fallacy').

 

Here are the reasons:

 

1. While the original design of the STEREO plugs was done such that the right channel would not be shorted when plugged into a MONO jack, the assumption that this is true under all conditions is false. Some MONO jacks DO short the right channel to ground. Others don't. I've measured this myself and found both varieties. Got the impression that plugs/jacks of recent (Chinese ?) manufacture cause a short of the right channel to ground more often than not. Sloppy manufacturing on worn out equipment may contribute. So why take the risk ? Making foolproof cables which won't cause the short under any condition is safer to avoid damage.

 

2. Turning down the volume on the right channel on a STEREO source sure can avoid frying the right channel amplifier in case of a short circuit, but the next time you experiment you might forget it and leave the volume cranked up and then, if you have a short, sh*t happens.

 

3. Once upon a time, many ages back, electronic engineers knew how to design short circuit proof audio amplifiers. They would employ both overcurrent and overtemperature protection in the output stages. The circuits to do that cost a few transistors, but are cheap, and work, as evidenced by the 78XX family of voltage regulators (they are virtually indestructible unless the max. input voltage is exceeded or if they are reverse biased: output voltage forced higher than input voltage). But all this knowledge apparently is lost in time. Modern electronics appear to be designed by idiots. They don 't last. They get zapped / damaged too easily because there are no functional self-protection circuits. Even Chinese made  knockoffs of the 78xx regulators do die when their output is short circuited. Because the idiots who copied them don't know how the protection circuits are supposed to work and how to dial the process to the right point / adjust the masks to the right trip points for the current limit. (The same thing may happen when one large semiconductor outfit buys another one, lays off the original designers they got with the deal, and then migrates the product lines bought to their own process technologies - a recipe for disaster. I'd say keep the original designers and test engineers around at least until  after  the migration was successful and the products can be produced again, but greed, narcicissm and psychopathology in the C-suite prevents such proper reasoning. Note: according to the esteemed DSM manual, the latter two are mental diseases. These people should not be in the C-suite, but in Arkham Asylum).

 

As far as I'm concerned, I've seen the rise of the microprocessor and I've had a stellar career and raked in a lot of money for my work. But since maybe 20 years, I've seen an accelerating trend of rot and decay which manifests itself in lousy to hilarious academic papers, worthless but nasty patents, unreliable ICs fully of bad surprises, not all being documented in the maybe 200+ pages of technical bugs and flaws attached to the datasheet, but only given to the customer upon request and under NDA, bad electronics in the field, like the dishwasher that dies in the 7th month after the 6 months warranty has expired, and the computerized cars which are unusable because the dealership could not eradicate the electronics gremlins even after having changed all the black boxes on the customer's dime, and so on. I'm glad that I'm retired. It's no fun to work with such cr@p and under such conditions. But don't despair - the ubiquitous incompetence and the poor quality of products it causes opens up  lots  of opportunities for young people with a brain and with skills to make   lots   of money by fixing these things. "In the land of the blind, the one-eyed is king."

 

- Uncle Bernie

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Always look at the pinout

Always look at the pinout prior to plugging-in to see what goes where and then check with a multimeter that no output gets shorted. There are too many combinations to do it any other way, especially with smartphones, tablets and laptops that use TRRS:

 

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A way to get a MONO plug from

A way to get a MONO plug from a stereo source without having to fab your own cable is to buy a Stereo 3.5mm to Mono 3.5mm Y splitter cable.

 

A search on Amazon that will find that is 'stereo to mono splitter 3.5mm'.  Just make sure you get one that is all 3.5mm because a lot of splitters are 3.5mm stereo to 1/4" mono, and you don't want that.

 

This looks like a good one:

 

https://www.amazon.com/Breakout-Splitter-Adapter-RFAdapter-Headphone/dp/B08XHBR8TJ/ref=sr_1_3?crid=279VDLL45FNA7

 

 

 

 

 

 

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UncleBernie wrote:1. While
UncleBernie wrote:

1. While the original design of the STEREO plugs was done such that the right channel would not be shorted when plugged into a MONO jack, the assumption that this is true under all conditions is false. Some MONO jacks DO short the right channel to ground. Others don't. I've measured this myself and found both varieties. Got the impression that plugs/jacks of recent (Chinese ?) manufacture cause a short of the right channel to ground more often than not. Sloppy manufacturing on worn out equipment may contribute. So why take the risk ? Making foolproof cables which won't cause the short under any condition is safer to avoid damage.

 

While great details, are you saying the II family has different parts in the II,II+ and IIe that were constructed differently? Have you looked at the jack construction? AFAIK the II jack always followed a single switched design (similar to what was shared earlier), maybe different suppliers but always the same internal design but it's been a while since I last looked that close. This would make sense as Apple needed to find suppliers that met Apple's requirements and those reqirements were ment to protect the IIs. I'm sure you also know the II cassette port entry is threaded metal and tied to ground. So on almost every entry the tip makes contact with that ground so the left channel would have the same shorting problem you described but that's not really a problem. Of course one should never hot connect devices, but we all know the general public does so all the time and why tye protections were put in place to start. 

 

2. Turning down the volume on the right channel on a STEREO source sure can avoid frying the right channel amplifier in case of a short circuit, but the next time you experiment you might forget it and leave the volume cranked up and then, if you have a short, sh*t happens.

We're talking line level inputs/outputs, there should be no amplification and why the ~<4VPP (-2/+2V) range. If someone is connecting speaker output from a 100W receiver into their II, well that's a user problem. Engineers should not be responsible for designing around users doing really dumb things, you can imaging many dumb things that we'd need to protect against... nothing would ever get released or be so expensive no one could afford them.

 

3. Once upon a time, many ages back, electronic engineers knew how to design short circuit proof audio amplifiers. They would employ both overcurrent and overtemperature protection in the output stages. The circuits to do that cost a few transistors, but are cheap, and work, as evidenced by the 78XX family of voltage regulators (they are virtually indestructible unless the max. input voltage is exceeded or if they are reverse biased: output voltage forced higher than input voltage). But all this knowledge apparently is lost in time. Modern electronics appear to be designed by idiots. They don 't last. They get zapped / damaged too easily because there are no functional self-protection circuits. Even Chinese made  knockoffs of the 78xx regulators do die when their output is short circuited. Because the idiots who copied them don't know how the protection circuits are supposed to work and how to dial the process to the right point / adjust the masks to the right trip points for the current limit. (The same thing may happen when one large semiconductor outfit buys another one, lays off the original designers they got with the deal, and then migrates the product lines bought to their own process technologies - a recipe for disaster. I'd say keep the original designers and test engineers around at least until  after  the migration was successful and the products can be produced again, but greed, narcicissm and psychopathology in the C-suite prevents such proper reasoning. Note: according to the esteemed DSM manual, the latter two are mental diseases. These people should not be in the C-suite, but in Arkham Asylum).

Amen!! Built to last is a lost art in todays cost-reduced world.  Bonus points for working DSM made it into a II discussion, that may be a first!

 

As far as I'm concerned, I've seen the rise of the microprocessor and I've had a stellar career and raked in a lot of money for my work. But since maybe 20 years, I've seen an accelerating trend of rot and decay which manifests itself in lousy to hilarious academic papers, worthless but nasty patents, unreliable ICs fully of bad surprises, not all being documented in the maybe 200+ pages of technical bugs and flaws attached to the datasheet, but only given to the customer upon request and under NDA, bad electronics in the field, like the dishwasher that dies in the 7th month after the 6 months warranty has expired, and the computerized cars which are unusable because the dealership could not eradicate the electronics gremlins even after having changed all the black boxes on the customer's dime, and so on. I'm glad that I'm retired. It's no fun to work with such cr@p and under such conditions. But don't despair - the ubiquitous incompetence and the poor quality of products it causes opens up  lots  of opportunities for young people with a brain and with skills to make   lots   of money by fixing these things. "In the land of the blind, the one-eyed is king."

 

Again, AMEN! Long gone are the days when things worked and worked forever because they weren't designed to be reliable not disposable. Welcome to the world of economics, competetive advantage and the large number of uninformed consumers who only look at the price when buying. That being said there are companies like LG which appear to have learned from their mistakes of the 80's. Their rep was so bad they had to ditch their original name, but everyone who lived in the 80s should remember Lucky Goldstar (nothing good comes with luck in business name).  Today they seem to have got some products which are 10000x better than what they made in the 80s. RCA, Westinghouse and others who use to be THE name in good products have fallen into the re-branding trap and today they are crap. But, bottom line wins when consumer is only concerned about the price, not about quality, where the product was made, if their neighbor has a job, or working conditions half-way around the world. Economists should be viewed like lawyers, because they can't understand there's way more to the picture than just production costs and retail price, period. (stepping down from my soap box)

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The risk of shhorting the right channel is real !

In post #11, Jeff D wrote:

 

" While great details, are you saying the II family has different parts in the II,II+ and IIe that were constructed differently? Have you looked at the jack construction?  "

 

Uncle Bernie answers:

 

I have one Apple IIe and a Taiwanese 'PC 48' clone of the original Apple II. I also have an original Apple II motherboard which is a hopeless case of low quality IC sockets. I've checked all the TAPE IN jacks in these specimen with various STEREO audio cables I've collected over 40 years or so. Some of the cables have a shorted right STEREO channel when plugged in. Most cables don't produce that short but some, when the plug is wiggled, will make my conductivity tester wired between right channel and ground beep.  So there is a chance to get a short even with original Apple II motherboards. But the culprit - in  all cases where a short was observed - is the plug, not the jack on the motherboard. I think something is mechanically out of spec with these plugs, the far east manufacturers just don't seem to care.  I've indeed inspected the construction of the jacks on the motherboard. A fully inserted, in-spec STEREO plug will have the "Ring" clearing the ground tube. But it's a very small clearance. If the stem of the plug is not in spec (too short) or if the injection mold of the plug's body is too inaccurate (so the plug can't be fully inserted) or if the "Ring" is off center (I had a few of these cases, too) then this may produce said short of the right channel to gound. Which under ideal conditions and everything in spec should never happen. I have found that the situation with 3.5mm jacks bought off Ebay is much worse, most make a short, except the very expensive ones. I have specimen of all these at hand so I could repeat the measurements to prove my point. All this is just decay / decline of sound manufacturing practices. I also got the impression that Chinese sellers of cables / jacks /plugs might sell factory fallouts / rejects they stole out of the trash bin of the factory. This is because the quality is so poor. But maybe they can't do any better. Who knows.

 

The issue with shorting the right channel on STEREO cables was most severe with the Apple-1 ACI cards. To mitigate the risk of any damage to media players of builders of my kits, I generally recommend to make these foolproof cables where the right channel is disconnected. It's a cheaper solution than to buy a new media player or PC sound card or notebook computer. Oh, and I had one cheap media player which got damaged during my early experiments with the Apple-1 ACI some years ago. It worked fine to play recorded files of cassette software to the Apple-1 but after that I discovered that the right channel was dead. So it was useless for listening to music. I had to throw it away. IIRC, I once paid $29.95 for it. Plus sales tax. Would hate that this happens to anyone using an iPod. These are much, much more expensive. (Better safe than sorry).

 

- Uncle Bernie

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My experience dealing with

My experience dealing with Chinese manufacturers is that they vary widely in capabilities.  Some can make good stuff, others are mediocre at best.  The good ones can make great quality stuff, IF you write the contracts correctly.  You have to ride them on QC, because if you don't they will try to cheat you and slip you inferior or even outright defective product.  You have to write the contracts so that they eat all the costs of defective goods.  That won't come cheap of course, if they have to do QC on their side they'll expect to be paid for it.  However, it is my experience that it is worth paying for it, because QA, like manufacturing ic cheaper in China than here.  You still have to do some QC on this side of the ocean but it is better than if you just let them ship you whatever.  It's a constant battle dealing with that, but unfortunately for a lot of things there aren't really any alternatives and in many cases there aren't any cost effective alternatives.

 

My experience with sellers out of Hong Kong, Tiawan or Korea has been significantly better.  They usually are more expensive to begin with but their QC is also generally better by default.

 

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OMG you guys are awesome! So

OMG you guys are awesome!

 

So much good information.  Plus people here know space out text for easy reading haha

 

Since I don't own so much as a multimeter, I just spent $400 on misc electronics gear to teach myself how to solder and do some other basic electronics stuff.  Not all that would be required to make this cable, but this endeavor was meant to be a learning experience so here we go.

 

I'm sure I'll be using my disk drives by the time I get the cable made, but I will definitely finish this exercise, get the cassette problem fixed, digest everything written here so far and report back for the benefit of future viewers.

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