Có nên dùng máy rửa mặt sau khi dùng nước trà xanh rửa mặt

[kmurta]

Has anyone built or used one of the ZX81 clock doublers ? If so where there any gotyas or was it difficult to get working ?

I use it through the ZXULA-2, an ULA replacement made by Andy Rea some time ago:

Here it running the CLCKFREQ test, with ZXpand patched with ZX81X2 ROM:

https://youtu.be/6Py3NUiEoDs

I swapped the original 4Mhz Z80 for another of 20Mhz that I had available, but an 8 Mhz Z80 is sufficient.

Please provide more details of the implementation you are using so that someone can help you.