CCWN76:86
                                                       
ror some of thc states, thc next •tate ls ~ Ys the sames the keyer always
goes ftom SENDIT1 to 8END2T2, or from SENDAH1 to SENDAH2 to SEffDAH3 to
SC9DAH4, HowewerR ln some states the weyer must examlne tne wpaddle

•lstoryt to see what GtZt~ tO enter next,Jror lnst~nce, when in SCHDIT2

•tote (fintshlnq sendSna a ditZ, the weyer •ends a dah next tenters
SENDAHt ) lf the dah paddle nas been depressed, If the dan paddle has not been
depressedw and the dit paddle has been~ Rt w ntcr sEND2Tl and send another
dit, 2+ netther paddle has been dearessedR ft ~nttrs SlNDCSI ana startr to sen
a charzcter space,

The paddle history 1s re bered by thre~ set-r~et fliDwflops whose outPuts
are DITUEM~ DAMMEM, Ond DAH94D2T, The D1TMEM P"f10P 1S set by the dit Padd
lt rcset when the keyer ~ntcrs sENDIT1, Likewlse~ the dah paddle sets the
DAMMEM P~£lOp~ which ts reset on enttrsnX AH1, tne DAHB4DIT £11DW£1OD
ls set i! DAHMEN 1s on~but DITTMEM t~ off e DAS , DA DST lS reset
when the teyer enters SSND~H1 •tate,

Ttlrteen fourwblt binary nuserals~ from 0000 to 1100, represent the thlrteen
state aderesses~ These four bltS~ toqether wlth the out~ats Of the raddle
hlstory fllpwflops~ comprlse the address ltnes of ~ speclal type of read~only
memorys 4 fleld prOBrammoble loxlc arraY t!P; s the weyer progresses frem
state to state, lt ~oves from entty to entry ln a table reeorded ln that rpLAf
Seven of the •tQht rPLA OUtDUt llnes •re usedt

        , tour llD@S ~PeCt£Y the state ~ddress of the next state to be
          state to be entered ese lines aO tO tYpe D £11PWf10PS. whlch
          trans2*r that •tate address tO the statc address tnpUt llnes on
          the next elock oulse.
          
        , T<O Slnes reset the paddle hlstory hstory fllp-flo¢s,
        
        , The l~st outDut llne 1S thc ReYer outputs hlqh for wmark~" low
          for ~sPace~
          
riqure t snOws the tcyer ~chemZtles besldes the FPLA, a 7417S ruad D fllP9flOt
and two 74on cu~d NANP uates ~re used,

rrqure 2 snows th~ progre~*lon fro~ state to state, The lett ssde of the tablt
shows lnputs to th~ tPLA~ and the riqht slde shows the corresPondlnq outputs,
Deslsnlns the teyer eontists malnly of m*tlnq up thls tablc~ Therc are fourtef
iniut llnes, o2 whlch seYen are used, Th~s~ acecss 29 di2ferent words of rpLA
memory, tThe rPLAt unllke other mecories~ ean lXnore sone of /tr lnPuts, •o
that 1! a partleular state doesn't need tO cXamsne the paCdle hlstory
f11D@f1ODS~ those lnput llnes can be ignored~ Thls reduees the number of word
tO be proArammed lNto the rPLA,) The elqht tPLA OUtpUt bitS ~re determined
from the rlxht half of thc tablew they name the •ddress Of tne next state to
be entored~ deteralne whlzh flipoflopS are tO be reset, and provid~ tne
Kever output,