CMOS troubles

I connected VI1 to myself according to the second version of R. Milyukov (in the original - Gluck), but
it is buggy... If you open access to the ports (out #eff7, #80), then the computer hangs.
It looks like the VI is leaking on the data bus in the interrupt confirmation cycle.
But why? And how can I get rid of this?

With respect, Vladimir.

P.S. The options “connect according to the first option” and “change the device” are not to be offered. All the VIs available to me work in exactly this version
of inclusion and have such a glitch.

* Crossposted in HARDWARE.ZX
* Crossposted in REAL.SPECCY

... "That prikriy svit shtovha⌡ i kida⌡" (c) Scriabin