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Ken · 6th Aug 2017, 1:31 pm

Hello Jay,
I'm not sure that I have a scope that is working properly but I do have a device for measuring frequency built from a Chinese kit. I am not currently sure of its range. I seem to remember reading that the CPU is running at 3.5MHz but this is derived from a 7MHz source generated elsewhere. It might have been in the ula but I can't remember. Should I see 3.5 or 7MHz on the cpu or have I got this wrong.

Regards,

Ken.

6th Aug 2017, 1:31 pm	#56
Ken Hexode Join Date: Oct 2003 Location: Near Glasgow, UK. Posts: 309	Re: Sinclair ZX81 Hello Jay, I'm not sure that I have a scope that is working properly but I do have a device for measuring frequency built from a Chinese kit. I am not currently sure of its range. I seem to remember reading that the CPU is running at 3.5MHz but this is derived from a 7MHz source generated elsewhere. It might have been in the ula but I can't remember. Should I see 3.5 or 7MHz on the cpu or have I got this wrong. Regards, Ken.