Star Micronics NX-1001 User Manual page 83

I
DEFINING YOUR OWN NLQ CHARACTERS
As you probablynoticed,NLQ charactersare printedby two passesof the
printhead.Halfofthecharacterisprintedonthefirstpass,andtheremainder
onthesecondpass.Thepaperis rolleduphalfa dotheightinbetweenpasses
to let the printhead printdotson the secondpass that overlapthe previous
dots,in otier to fill in the spacesand producedensercharacters.Addition-
ally,tie print head speed is halved,and the dots are printed at doublethe
densityof draft characters.For this reason,NLQcharacterscan containup
to 23 dots in the horizontaldirection.
Fundamentally, t heprocessto defineandprintdownloadedNLQcharacter
is the same as for draft charactem,exceptthat youmust supplyaboutfour
timesasmuchcharacterdata,andyoumustdesignthecharacterwiththe?SVO
passes of the print head in mind. There are small diffextmces with the
standardmode in the way the attributeinformationis processedalso.
In the draft qualitymodethe attributebyte carriesthe descenderdata, and
specifiesthe left spaceandthe characterwidth.In the NLQ mode,the first
bit also carries the descenderdata, and the next three bits describe the
character'sleft space as with the draft charactem,but the last four bits
describethe right space.Appropriateallocationof data in these sevenbits
lets you place the character whe~ you like within the grid, with the
nxtrictionthat the charactermust be at least 9 dots wide.
Usethe gridin Figure5-4 to helpplotthedata.Dueto thetwo-passprocess,
NLQcharacterscan containup to 16dotsvertically.ml to m23 arethe data
for the first pass, and m24 to m46 are the data for the secondpass.
To makethe characterdataeasierto calculate,put the first pass dotsinside
theboxesonthegridwhenyouaredesigningyourcharacters,andthesecond
passdotson the lines.Rememberthat adjacentdotsmay not overlapon the
samepass;in otherwords,if onedotis in a box,its adjacentdoton the same
passmaynotbeon aline.l%erefom,to makesmoothcharactm, putthedots
neededto overlapany spacesin a characterin the appropriateplacesin the
secondpass grid.
If weplotourcar-shapedsymbolforNLQ,thegriddatawilllooklikeFigure
5-5.
Thedefiningprocessisthesameas fordraftcharacters, e xceptthatyoumust
selectNLQ mode, and you must define46 data. If you wish to print your
NLQ characterswith the regularcharacterset, the remarks regardingthe
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