You could trying something like this. You'd have to play around with font/size to find something you like. (you could do some pointresizing if you want it even blockier.)
src=clip
blankclip(src)
subtitle("hello world!",halo_color=$FF000000,text_color=$00FFFFFF,align=5,\
font="Fixedsys",size=24)
mask=levels(0,1,1,0,255)
layer(src,mask.mask(mask))
#this will let you change the color of the text.
layer(src, blankclip(src,color=$00FFFF).mask(mask))
#adjusting the 127/128 values will change how much of the antialiasing it keeps.
mask=levels(127,1,128,0,255)
#using this will give less smooth anti-aliasing
mask=levels(0,1,192,0,3).levels(0,1,3,0,255)
