NCR RealPOS 70 - Invert Screen (0 Ah); Reserved (0 Bh - 0 Fh); Character Codes (10 H - Ffh)

Chapter 11: APA Customer Display Interface 11-11
Invert Screen (0Ah)
Thiscommandlogicallyinverts(0ʹsbecome1ʹs,1ʹsbecome0ʹs)the
contentsofDDRAMselectedbytheHandGbits.Inthemonochrome
mode(G=0)onlyPage0isaffected.TheXAR,theYAR,andthedata
controlbitsarenotaffectedbythiscommand.
Reserved (0Bh - 0Fh)
Thesecodesarereservedforfutureuseandarecurrentlyignoredby
themodule.
Character Codes (10h - FFh)
Datavaluesreceivedbythemodulethatarewithintherange10h
throughFFh,arecharactercodes.Thecharacterselectedfromthe
charactertablebythecharactercodeiswritten,usingthecurrent
characterwriteanddatawritemodes,intotheDDRAMlocation
addressedbytheXAR,theYAR,thedata
controlbits.TheXARand
YARpointtotheDDRAMlocationthatthelefthandsideofa5x7
(upperlefthandsideofa10x14)characterwillbestored.
Thiscommandadds1*blankcolumnto5x7charactersor2*blank
columnsto10x14characters,forcharacterspacing.
This
commandalsoautomaticallyincrements(I/D=0)ordecrements
(I/D=1)theXandYaddressregisterstopointtothenextcharacter
(somecharactersarewiderthanothers,seefonttableforsizes).YAR
overflows,127to0,incrementtheXAR(by2for10x14characters)and
YARunderflows,0to127,decrement
theXAR(by2for10x14
characters).Charactersaretop‐justifiedleavingthebottompixelrow(2
pixelrowsfor10x14characters)*blank.
*ʺblankʺisdependentonthecurrentdatawritemode.