Author Topic: CPC6128 cassette port  (Read 719 times)

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Offline JD

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CPC6128 cassette port
« on: 18:47, 20 January 21 »
Hi friends,


I've been playing with my CPC's lately, and I'd like to get some more use out of my 6128 - I don't have much disk based software for it so my 464 tends to see more action.


I realized that, since I last used the 6128, I now have a cassette player with a 5-pin DIN output, which I bought for use on my Acorn Electron and BBC. It works very well for both of those systems, but plugged into the Amstrad, there's no sign it can hear the tape signal at all. I've entered the prerequisite |tape command, and heard the motor relay on entering run" command (and hitting another key). I've tried various different volumes and various different tapes, some of which sound very muffled to be fair (but load flawlessly on the 464), and I've tried a signal straight from my laptop using CDT2WAV. I've never once had it pick up a header, or produce an error - it just waits. I've even tried writing a small BASIC program to look for any signs of a bit switching on port &F500 (correct me if my logic was flawed there), but nothing changes.


I'm left thinking that either:
- my 6128 has a hardware problem? (I bought it used a few years ago, and don't know its history)
- it needs a differently wired DIN cable than the one I use with my Acorn computers?
- the signal I can generate through my cassette recorder just isn't good enough?


If you know any further things I could check, that would be appreciated. :)


thanks for reading!

Offline Bryce

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Re: CPC6128 cassette port
« Reply #1 on: 19:34, 20 January 21 »
Hi JD,
number 2 was the correct answer...

- it needs a differently wired DIN cable than the one I use with my Acorn computers?

Bryce.

Offline eto

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Re: CPC6128 cassette port
« Reply #2 on: 23:30, 20 January 21 »

Offline JD

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Re: CPC6128 cassette port
« Reply #3 on: 23:43, 20 January 21 »
Thanks guys, I had a brief look at the pinout for the Amstrad and BBC last night but clearly I had my eyes shut  :picard:


Does that mean this product here is advertised incorrectly? There doesn't seem to be an option for which computer to support.


https://www.ebay.co.uk/itm/5-PIN-DIN-180-PLUG-to-PLUG-LEAD-AUDIO-or-ACORN-AMSTRAD-COMPUTER-to-CASSETTE/233645709701


Offline Bryce

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Re: CPC6128 cassette port
« Reply #4 on: 10:29, 21 January 21 »
Thanks guys, I had a brief look at the pinout for the Amstrad and BBC last night but clearly I had my eyes shut  :picard:


Does that mean this product here is advertised incorrectly? There doesn't seem to be an option for which computer to support.


https://www.ebay.co.uk/itm/5-PIN-DIN-180-PLUG-to-PLUG-LEAD-AUDIO-or-ACORN-AMSTRAD-COMPUTER-to-CASSETTE/233645709701

Yes, he's selling a standard 1 to 1 connection cable and claiming it will magically work on all sorts of systems as if the pinout was always standard, which it wasn't.

Bryce.

Offline eto

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Re: CPC6128 cassette port
« Reply #5 on: 10:33, 21 January 21 »
I would expect that is a simple cable that connects pins 1:1. Unless a pin is not connected or a cable is broken, the cable would be advertised correctly. Can you check that with a multimeter, if they are properly connected?

One more idea: I just recognized that the Acorn and the CPC have their input on different pins (right vs. left audio channel). I remember, that I once had a cassette player which did only output on one channel. Can you check if your cassette player maybe only outputs on pin 1?

Offline Bryce

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Re: CPC6128 cassette port
« Reply #6 on: 11:43, 21 January 21 »
I would expect that is a simple cable that connects pins 1:1. Unless a pin is not connected or a cable is broken, the cable would be advertised correctly. Can you check that with a multimeter, if they are properly connected?

One more idea: I just recognized that the Acorn and the CPC have their input on different pins (right vs. left audio channel). I remember, that I once had a cassette player which did only output on one channel. Can you check if your cassette player maybe only outputs on pin 1?

How do you work that out?


CPC pinout: 1 - Remote, 2 - GND, 3 - Remote, 4 - Data In, 5 - Data Out.

Acorn pinout:  1 - Data Out, 2 - GND, 3 - Data In, 4 - Data Out, 5 - Not connected.

MSX Pinout: 1 - GND, 2 - GND, 3 - GND, 4 - Data Out, 5 - Data In.

Most common cassette players followed the Amstrad pinout, however, many didn't have the remote start/stop and had Data In / Out duplicated on pins 1 and 3.
So how is a simple 1 to 1 cable going to connect any of these together as simply as the seller suggests?

Bryce.