[GreenKeys] reperf turn on/off

[Jim Haynes]

On Mon, 25 Feb 2019, epvgk at limpoc.com wrote:
>
> For what it's worth, my M28 powers down completely when it receives,
> in order, FIGS, NULL, H.
>
Yes, that was more or less standard on M28s.  And on Model 15 there was
a similar feature operating on upper case H, and the bit about 
reperforator controls notes that it is incompatible with printer motor
control.