for (;;) { write-host -n (get-random ╱,╲) }
Obviously this requires a font supporting those characters. MS Mincho seems to serve well: http://www.microsoft.com/typography/fonts/font.aspx?FMID=206
for (;;) { write-host -n (get-random /,\) }
for (;;) { write-host -n (get-random '_','|') }
for (;;) { write-host -n (get-random ╱,╲) }
Obviously this requires a font supporting those characters. MS Mincho seems to serve well: http://www.microsoft.com/typography/fonts/font.aspx?FMID=206