Sinclair ZX80 / ZX81 / Z88 Forums

resonators
MURATA CSTLS6M50G53-B0 (Farnell), (Mouser)

For example…

Mark

1024MAK wrote: ↑Wed Nov 08, 2023 6:38 am resonators
MURATA CSTLS6M50G53-B0 (Farnell), (Mouser)

Thanks Mark, they look like a drop-in replacement.
The minimum order amount for Mouser and Farnell orders makes this more of a problem.

Cricklewood Electronics have one.

But do test the 3.25MHz clock from the ULA (pin 14) and pin 6 on the Z80 before going any further.

Mark

1024MAK wrote: ↑Wed Nov 08, 2023 2:24 pm Cricklewood Electronics have one.

But do test the 3.25MHz clock from the ULA (pin 14) and pin 6 on the Z80 before going any further.

Will do Mark, thanks again.

I'm glad to say this problem has been solved, the problem wasn't the crystal it was some suspect soldering on the legs of C9 and pin 6 of the ROM chip socket.
Now the board boots up and works

Excellent news

Mark

Another Phoenix rises from the ashes, brilliant

Thanks, all.
I look forward to using it

Although this issue 1 ZX81 didn't have a faulty resonator, I bought one of the 6.5 Mhz resonators that Mark noticed from Cricklewood, before I found the soldering that I missed.
This ceramic resonator, which has the same form factor as the stock item, does work in this Zeddy but there's a slight difference on the monitor I was using, which is that there's a ghost line under the cursor;
I entered an 8-line program which checks the available ram and although the ghost line was under the cursor and text on the cursor line, it wasn't anywhere else so far;

It wasn't on the cursor line when the program completed;
This may be artifacts produced by my little HDMI/VGA/Composite monitor, I haven't another monitor on hand to test.
After reading the ZXVid manual, I found that one pot controls the contrast and the other controls the output level, which can help with effects like ghosting.

In addition to this Cricklewood resonator, I also found a 6.5536 Mhz crystal on eBay, which I also tried and likewise, it worked and the display was better with no ghost under the cursor line;

But for some reason the cursor isn't quite right!
Interesting