<s>
The	O
IBM	B-Device
System/370	I-Device
Model	I-Device
145	I-Device
was	O
announced	O
September	O
23	O
,	O
1970	O
,	O
three	O
months	O
after	O
the	O
155	B-Device
and	O
165	B-Device
models	O
.	O
</s>
<s>
It	O
was	O
the	O
fourth	O
member	O
of	O
the	O
IBM	B-Device
System/370	I-Device
line	O
of	O
computers	O
,	O
and	O
was	O
the	O
first	O
IBM	O
computer	O
to	O
use	O
semiconductor	B-Architecture
memory	I-Architecture
for	O
its	O
main	O
memory	O
instead	O
of	O
magnetic	O
core	O
memory	O
.	O
</s>
<s>
It	O
was	O
described	O
as	O
being	O
five	O
times	O
faster	O
than	O
the	O
IBM	B-Device
System/360	I-Device
Model	I-Device
40	I-Device
.	O
</s>
<s>
The	O
System/370	B-Device
'	O
s	O
basic	O
architecture	O
was	O
described	O
as	O
having	O
been	O
an	O
extension	O
,	O
but	O
not	O
a	O
redesign	O
,	O
from	O
that	O
of	O
IBM	O
's	O
1964-introduced	O
System/360	B-Application
.	O
</s>
<s>
Some	O
said	O
about	O
the	O
early	O
members	O
of	O
the	O
IBM	B-Device
System/370	I-Device
family	O
,	O
looking	O
back	O
,	O
that	O
they	O
were	O
not	O
"	O
the	O
real	O
370	O
line	O
"	O
because	O
"	O
neither	O
offered	O
virtual	B-Architecture
storage	I-Architecture
capability	O
,	O
which	O
was	O
to	O
be	O
a	O
hallmark	O
of	O
the	O
370	O
line.	O
"	O
</s>
<s>
Unlike	O
the	O
earlier	O
Model	O
155	B-Device
and	O
165	B-Device
systems	O
,	O
for	O
which	O
an	O
upgrade	O
to	O
virtual	B-Architecture
memory	I-Architecture
required	O
the	O
purchase	O
of	O
an	O
expensive	O
upgrade	O
to	O
add	O
a	O
DAT	O
box	O
,	O
the	O
145	O
's	O
customers	O
had	O
two	O
advantages	O
:	O
</s>
<s>
there	O
was	O
no	O
need	O
to	O
buy	O
extra	O
hardware	O
:	O
An	O
upgrade	O
to	O
the	O
145	O
's	O
microcode	B-Device
through	O
a	O
new	O
microcode	B-Device
floppy	O
disk	O
enabled	O
virtual	B-Architecture
memory	I-Architecture
capability	O
.	O
</s>
<s>
Upon	O
gaining	O
virtual	B-Architecture
memory	I-Architecture
capability	O
via	O
a	O
microcode	B-Device
update	O
,	O
the	O
145	O
could	O
now	O
support	O
the	O
VMF	O
(	O
Virtual	O
Machine	O
Facility	O
)	O
and	O
VM/CMS	B-Operating_System
,	O
a	O
time-sharing	B-General_Concept
system	I-General_Concept
.	O
</s>
