[Info-vax] disabling a CTRL/Y ast

[Tom Adams]

Section 5.4.3.2 here:

http://www2.hmc.edu/www_common/OVMS072-OLD/72final/6136/6136pro_019.html

explains how to enable a ctrl/y ast using IO$M_CTRLYAST. It also says:

"This function code is also used to disable the AST."

but I cannot figure out the arguments of the QIOW call that would disable the AST.

How does one disable the AST?