Forn youenterthenumberoflinesperinchyouwant—anyof: 1,2,3,4,
6,8, 12,16,24or48. If youenteranumberotherthanthesetheprinterwill
ignorethecommand.
Defining the space and column
Beforeyouuseprintpositioningcommands,youfirstmaywantto change
thedefinitionsofthelineorspace(sometimescalled“verticalandhorizontal
motionindexes,”VMIandHMI).Thesedefinitionsdon’tactuallymovethe
print position.Instead,they define two basic units you can use in print
positioncommands.
What’simportantaboutthespaceisthatitdefineshowfartheprintposition
travelsforeverycharacteryouprint(exceptforproportionallyspacedtext).
Thespacecanalsobethoughtofasthewidthofaverticalprintcolumn.One
columnwidthisthewidthofthespacecharacterinthecurrentfont,nomatter
whetherit is monospacedor proportionallyspaced.
Occasionallyyoumay wantto changespacewidthto overridethecurrent
pitchsetting. Let’slookatanexample.Thespacewidthcomesinunitsof
l/120thofaninch,andtheCourierfontcanprintIOcharacterspcrinch.Each
charactercoversa tenth—12/120the of an inch, so that font’sdefault
spacewidthis 12units.If we changeits spacewidthto 6, eachcharacter
wouldhalf-overlaptheonebeforeit.
If youareusing<S1>and<SO>to shiftbetweena primaryandsecondary
font,it’s a goodideato changethespacewidthaftereveryshift.
To changethespacewidthyousendthiscommand:
<ESC>&k n H
inwhichfornyoucanenteranumberfromO(zero)to840.AwidthofOwill
printcharacterson top of eachother;a widthof 840willprintthemseven
inchesaprt.
Defining line depth
Thelinedepth(sometimescalledthe“verticalmotionindex”)specifieshow
fardownapagetheprintpositionwillmoveforeachlinefeed.Youprobably
won’tusethelinedepthasmuchaslines-per-inch.Linedepthcanbemore
precisebutitisn’taseasytocalculate.Thelinedepthcomesinmultiplesof
l/48thof an inch.
Theimportantfactaboutthelinedepthisthatwhenyouchangeit youare
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