Information Technology Reference
In-Depth Information
by.computers.today,.because.as.with.nearly.all.digital.systems.
that. evolved. over. time,. they. simply. do. the. same. things. we.
have.always.done.but.faster.and.more.eficiently.
So,. when. your. great. grandma. Betsy. wanted. to. call. her.
local.pharmacist,.here.is.what.happened.
Back. in. the. day,. the. telephone. company. had. a. central.
ofice.in.every.town..In.that.ofice.sat.the.“operator,”.or.many.
operators..No.doubt.you.have.seen.a.picture.or.an.old.movie.
with.a.woman.sitting.in.front.of.a.large.switchboard.with.a.
lot.of.wires.plugged.into.it.or.hanging.loose.and.a.headset.on.
her.head.(Figure 3.10).
When. grandma. picked. up. the. phone. at. her. house,. the.
hook.switch.turned.on.a.light.over.the.corresponding.socket.
on. the. operator's. switchboard. (let's. call. her. Adele).. Adele.
plugged. in. a. cord. to. the. indicated. socket. and. was. able. to.
talk. to. Betsy. who. told. her. she. wanted. to. talk. to. Tom,. the.
pharmacist..Adele.said,.“Why.certainly.Betsy,.hang.on.while.
I. connect. you.”. She. then. unplugged. the. cable. from. Betsy's.
socket.and.plugged.it.into.the.pharmacist's.socket.and.pushed.
a.button.that.sent.a.signal.down.the.line.to.ring.the.pharma-
cist's.phone.
When.Tom.heard.the.ring,.he.put.down.his.mortar.and.
pestle. and. reached. over. and. picked. up. the. phone,. which.
Figure 3.10 Adele. the. operator. was. always. standing. by. at. her.
switchboard.
