Sinclair ZX80 / ZX81 / Z88 Forums

Hi, guys.

I would like to ask You for help.
I'm not sure if the MIC output of my ZX81 is operational.
I mean - until now I had only Spectrums. While saving their sound is loud and pretty clear.
But in case ZX81 I don't know if I have a broken MIC port or is it normal for ZX81 (I doubt) that the sound while saving is hardly/barely audible and very noisy (buzzing).
If I would record something like that on a tape, I doubt I would be able later to load it back into ZX81.

The only comparison I have - is to EightyOne emulator (F4=MIC sound on). There the sound is much more clear and audible (although still some noise is noticeable but is stops while saving).

Would anybody be so kind and explain me in a few words if my ZX81 is broken or maybe it's normal for it (??) or - maybe I do something wrong (I use a cable from ZX Spectrum. I admit that when I use original ZX81 cable - veeeeeery short - the sound is a bit stronger but still totally silent).

I will be grateful for Your advices.

Kind regards,
Yerz
http://zx81.republika.pl/

Come one, guys, I can't believe You don't use tape at all.
(Not to mention about sound demos).

Maybe anybody could record for me how his ZX81 saves or oen song from some music collection??????????????????????????????

Hi Yerz
Do you test it ? I mean do you SAVE some program, just a 1 line basic program for example, on tape and then LOAD it ?
does it work ?
Gus

You should get a nice strong signal. It sounds like (no pun intended) either:

Your mic socket is dirty/corroded
There's a loose connection

It's going to be mechanical as you're getting a tv picture and the ear output is basically the same signal as the video...

How are you measuring the signal? With headphones? That will be too quiet - you need some amplification. Are you using a line input on your recording device? That won't work as it expects a high power signal. It needs to be the 'microphone' input. I'm guessing you're using the PC as a recorder, right? If it works for spectrum it should work with zx81.

C

Hm, I must admit I haven't done it.
I mean I plug the ZX81 into PC and tried to SAVE "something" but the WAV had almost nothing except noise. :-\
That's why I abandoned the idea. However I inted to do it again, this time using original ZX81 cable (huh, the problem is the cable is 20 cm long).
Anyway this is only a part of the problem. Another part is to listen to the music coming from ZX81 (well, one channel but still music ).
I asked our hardware-guru - Yarek - and he said it might be veeeeeeeery old condenser/capacitor.
It would mean another opening the ZX81 and soldering. Arrrrrrrrrrgh.

That was to to GUS.
Also thx to Sir Morris. Hm. Yes, I use PC's line-in.
You think I should use mic-in? Hm.
Hm, hm, hm, hm, hm, hm, hm, hm, hm, hm, hm, hm, hm, hm, hm.
This new pieces of shit haven't it.
I will have to use the old one (that is kinda dead).
OK then, I will be still trying.
Thank You for the advices!!!!!!!!!!!!!!!!!!

You should be able to select what input the 'in' socket behaves as.

If you have a mixer control ticking 'mic' as the input source should switch the mode.

Good luck.