A friend sent this to me in text in an email. I checked online, wanting a souce I could link to. Looked at two or three results and two said source unknown, this one attributes the poem to a Martha Snow:
Spell chequer--Martha SnowEye halve a spelling chequer
It came with my pea sea
It plainly marques four my revue
Miss steaks eye kin knot sea.
Eye strike a quay and type a word
And weight four it two say
Weather eye am wrong oar write
It shows me strait a weigh.
As soon as a mist ache is maid
It nose bee fore two long
And eye can put the error rite
It's rare lea ever wrong.
Eye have run this poem threw it
I am shore your pleased two no
It's letter perfect awl the weigh
My chequer tolled me sew.