Elenco Electronics MO-1251 Instrukcja Użytkownika Pobierz pdf (Strona 6)

4

WHAT'S

NEWS

Packet proposed

for

shuttle

WAYNE WILSON WB8TSO OF

HEATH

COMPANY

(in jacket) presents

Gil Carmen,

presi-

dent of

the

Johnson Space Center

Amateur Radio Club, with the 1-1K -21 Pocket Packet

TNC, as club

members look

on.

Heath Company

recently do-

nated three

HK -21 pocket packet

TNC's (Terminal

Niode Controller)

to the

NASA Johnson

Space

Cen-

ter

Amateur Radio Club

in

Houston.

As part of the Shuttle

Amateur

Radio EXperiment

(SAREX),

it

is

proposed

that an

HK -21 be used on a

March

1990

shuttle flight.

Packet radio

allows

digitized

in-

formation-

voice, images, and

data -to be

transmitted over

radio

frequencies.

In

this experiment,

amateur radio band

frequencies

will

be used to transmit

packetized

data

to and from the shuttle.

If the

project

is approved, one

of

the packet radios

will

be

specially

adapted

for space travel.

NASA

will mount it into a protective

SAREX casing unit

and modifica-

tions

will be made

for

use

in zero

gravity.

Computer

controlled

system

uses

water for cooling

Possibly

the

most common

way

of

welding

metals

is to heat

them

with a

mixture of

oxygen

and acet-

ylene gas

(oxyacetylene).

That

method

has

its weaknesses

-acet-

ylene

is highly

flammable

and

re-

quires

careful

storing

in metal

containers.

Welding

must be

done

close

to the acetylene

source

to

keep pressure

high.

As you

may

remember

from

high

-school chemistry,

water

can

easily be broken

down

into its

components -oxygen

and

hydro-

gen

-with an electric current.

Those

gases

give out

intense heat

on

reuniting.

Now a

French system

that uses

complex computer

controls

ap-

pears to

have put an end

to the

difficulties

-such

as producing

large enough

quantities

of prop-

erly regulated gas

at a

workable

pressure -of

working

with oxygen

and

hydrogen.

The new

method

is

safer than

oxyacetylene

because

it

produces

only

the amount of gas

needed. The

flame, which is hot-

test at the core, permits

more

pre-

cise

work than oxyacetylene,

which is hottest at the edges.

Despite the cheap

fuel

source,

start

-up

expense

may be a severe

drawback, at

least for the small op-

erator. A complete system

will

cost

at

least $5000, as

compared

to

less

than

$200 for

an oxyacetylene

sys-

tem.

Industrial

users

will find such

costs

insignificant in view

of

the

lower

operating costs.

R -E

Oldest

floppy disk

This

floppy

disk,

unearthed at

the

site of the ancient Sumerian

city of

Lagash, extends the

history

of

personal

computing

back to the

third

millennium B.C. The person-

ALTHOUGH SOMEWHAT

OUTDATED,

this

computer disk

was once on

the leading

edge of

technology.

al

computer was previously

thought to

have

been

invented at

about

the time Columbus

was

busy discovering

new

lands,

and

only

in widespread use since

the

gold -rush

years made possible

gold -plated

connectors at a price

affordable to even

low- middle -in-

come settlers.

The inscription that

appears

on the protective

clay

sleeve

reads, in part, "The pro-

gram on this disk

is

protected by

(illegible)...to the

lions...

beheaded...Copyright

Microsoft

Corp.,

2900 B.C."

APR -1

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