JOY 5 *h[kIz k phL9̪I Y%z kZ-KiZ-K+L$ЦIz {x UL$ЦIz zx UL$ЦIz yx UL$ЦIz xx UL$ЦIz x UL$ЦIz ~x UL$ЦIz }x UL$ЦIz |x UL$ЦIz sx UL$ЦIz rx U xLayout 0x U pHomeoftheFree LChapter4 xLayout 0x U P ,p>>>x xLayout 0x U x xLayout 0x U  xLayout 1x U  $Layout 1xP #(-27systemsthatarearound.  Thesesystems,runbyenthusiasts,provideameansof  hconversingwithusersallovertheworldandmanysystemsalso D-providesomepublicdomainsoftwarefordownloading.Whatever,the  3chancesarethatyouwillmakenewfriendsandhavereadyhelpandradvicewithyourcomputingproblems. x$Layout 1xP #(-27=AUX:),followedbythetransmission(PIP  lAUX:=).Oncethefilehasbeenreceived,itcanbe  C,convertedbacktoa.COMfile,usingeitherLOAD.COMorHEXCOM.COM,suppliedwithCP/M.Px$Layout 1xP #(-27'DigitalResearchcorporation,microswereemergingaspropertools,  %notjusttoysforthesolderfreaks.Oneofthefirstobstaclesthat  *hadtobeovercomewasthatoftransferringdatabetweenthesenewQbeastsandtheir,high-powered,mainframebrethren. )WardChristensenwroteaprogramtodojustthat.Hecalledit  MODEM.Ithadallthenecessarycontrolsforactingasadumbremote jterminal.Laterversionsincludedfiletransferoptions,usinga.protocolcalledXmodem,devisedbyWard.  N7Theoriginalcodewasre-workedbyothers,principalamongst  'whomwereMarkZieglerandJamesMills.Eventually,itbecameMODEM7,whichhadmorefeatures,butnotafewbugs!  Fromthispoint,thereweretwoseparatestreamsofdevelopment S<-oneintheUKandoneintheUS.TheUSversionofMODEM7has  8!undergonevariousrefinementsandisavailableasMODEM7xx,wherethexxindicatesthecurrentversionnumber. In1983,DavidBackofShepperton,rewrotetheMODEM7codefor  I2UKusers,callingitUKM7.Thishasagainbeenadaptedforvarious  aJcombinationsofequipment,buttheessenceoftheprogramisthe  G0sameasDavidBack'soriginalandthereismuchsimilaritybetweendUKM7andtheUSversionsofMODEM7.  Startinguptheprogrampresentsyouwithasimplemenuscreen,  N7withanumberofoptions.Theprimaryoptionsarespecifiedfirst, withthesecondaryoptionsaddingfunctionality.Optionsarespecified@byasingleletterinthecommandline. hx$Layout 1xP #(-27'.Thissavesyouhavingtokeepthe|manualbyyourside,whenusingMEXinreal-time. 4TheSTATcommandbringsupascreenfulof'switches'thatyou  ?(canlaterwithinMEX.Thesecoverjustabouteveryoptionthatyou  iRcouldwant.Youmay,ifyouwish,maketheseswitchsettingsthe  permanentdefaultsettings.Onceyouhavethemasyouwish,justtype  'CLONENEWMEX.COM'andanewversionofMEXwillbesavedtodiskforyourfutureuse! TheMEXcommandsetis,inreality,amini-languageandyoumay  createtextfiles,usingthesecommands,thatMEXwilluseinsteadof  E.keyboardinput;ratherliketheSUBMITutilityofCP/M.Thisallows  K4youtouseMEXforunattendedoperationsincertaincircumstances  andyoucouldcreateseparatejobfilesthatwouldletyoulogonto  @)aremotesystem,downloadanynewmessagesandthenlogoff-all"withoutyourintervention! *MEXwillletyoudefinefunctionkeys.Upto64characterscan E.beassignedtoakeyandyoucansavedefinitionsinafile,tobexx$Layout 1xP #(-27slowerthanothercomms.programs.Moreover,theprotocolusedby  +KERMITisunique.ItisnotcompatiblewithXmodemandsoitisnot  3thebestpackagetousewithmanybulletinboardsystems(althoughtheFIDOsystemdoessupportKERMITprotocol). OnethemoreunusualthingsaboutKERMITisthewaythattalks  N7tothedeviceattachedtoit.Insteadofaddressingitasaserial  $ port,itusesCP/MBDOScallstotalktowhateverdeviceisassigned  XAasAUX:.Thiscanbeanyserialdeviceandtheadvantagetodoing (thisisthatyoudon'tneeddevicedrivers.Allyouneedtodoisto  E.alterthescreenhandlingcodesforyourterminal.Thatmakesita|veryportableprogram! K4Iwouldn'tsaythatKERMITisthebestcomms.programthatI  havecomeacross,butit'suseisalmostmandatoryinuniversitiesso,  G0ifyouhaveaccesstoJANET(theJointAcademicNetwork),youwilllikelyneedthis. *Thereareothercomms.packagesaroundandonethatyoumightXx$Layout 1xP #(-27