Hi, sorry, you have already mentiooned that your device is an HAMEG 103. Read page 12 in the manual for external triggering. (falling edge = '+/-slope' pushbutton in IN position)
Hi, now I can see them, but it is diffucult for me to estimate them. Please, choose a slower time base (2 to 5 times slower) to see mor periods. Your HAMEG is a two channel scope, isn't it? Please show on the second channel the MREQ-signal.
Hello! I've seen your new pictures. The signals at D2 and D3 look a bit strange (slow slopes), but not as bad that I would say that some RAM is faulty. Sorry, but for the moment I don't have more ideas. There is a diagnostic board for the ZX Spectrum, this could help you to solve the problem. Perhaps somebody with a diagnostic board is living close to you and could borrow it to you for some time?
Comments
sorry, you have already mentiooned that your device is an HAMEG 103. Read page 12 in the manual for external triggering. (falling edge = '+/-slope' pushbutton in IN position)
Thanks HZJ for instructions!
If I did it correctly, D0-D7 signals are:
No. I didn't. I checked in different browsers and it displays ok.
Direct link is http:// s11.postimg.org/sjo6ynnfm/image. jpg (just remove spaces after // and before jpg)
now I can see them, but it is diffucult for me to estimate them. Please, choose a slower time base (2 to 5 times slower) to see mor periods. Your HAMEG is a two channel scope, isn't it? Please show on the second channel the MREQ-signal.
Hello!
OK, I will change time and upload again. No, it's one channel. I will try to record both signals with same parameters and put it on one picture.
Hello!
I recorded both channels separately and join them on picture. First (upper) part of each picture is D0-D7 line, and lower part is MREQ line.
direct link is http:// s9.postimg.org/y8mluqo2m/Untitled_1. jpg (without spaces)
Y- ampl: 5V, X (time): 1us
I've seen your new pictures. The signals at D2 and D3 look a bit strange (slow slopes), but not as bad that I would say that some RAM is faulty. Sorry, but for the moment I don't have more ideas.
There is a diagnostic board for the ZX Spectrum, this could help you to solve the problem. Perhaps somebody with a diagnostic board is living close to you and could borrow it to you for some time?