<s>
The	O
IBM	B-Device
System/360	I-Device
Model	I-Device
40	I-Device
was	O
a	O
mid-range	O
member	O
of	O
the	O
IBM	B-Application
System/360	I-Application
family	O
.	O
</s>
<s>
On	O
April	O
7	O
,	O
1964	O
,	O
IBM	O
announced	O
the	O
IBM	B-Application
System/360	I-Application
,	O
to	O
be	O
available	O
in	O
six	O
models	O
.	O
</s>
<s>
The	O
360/30	B-Device
and	O
the	O
360/40	O
were	O
the	O
two	O
largest	O
revenue	O
producing	O
System/360	B-Application
models	O
,	O
accounting	O
for	O
over	O
half	O
of	O
the	O
units	O
sold	O
.	O
</s>
<s>
Like	O
most	O
System/360	B-Application
models	O
the	O
Model	O
40	O
was	O
microprogrammed	B-Device
.	O
</s>
<s>
The	O
microcode	B-Device
was	O
stored	O
in	O
transformer	B-General_Concept
read-only	I-General_Concept
storage	I-General_Concept
(	O
TROS	O
)	O
,	O
organized	O
as	O
up	O
to	O
8192	O
words	O
of	O
56	O
bits	O
each	O
.	O
</s>
<s>
Standard	O
microcode	B-Device
consisted	O
of	O
up	O
to	O
4096	O
words	O
.	O
</s>
<s>
With	O
the	O
additional	O
Compatibility	O
Feature	O
hardware	O
and	O
Compatibility	O
Support	O
software	O
under	O
DOS/360	O
,	O
the	O
IBM	O
1401/1440/1460	O
object	O
programs	O
could	O
be	O
run	O
in	O
the	O
emulation	O
mode	O
,	O
with	O
little	O
or	O
no	O
reprogramming	O
.	O
</s>
<s>
the	O
IBM	O
operating	B-General_Concept
system	I-General_Concept
used	O
was	O
usually	O
the	O
realistically	O
sized	O
DOS/360	O
,	O
because	O
all	O
but	O
one	O
model	O
of	O
the	O
360/40	O
had	O
less	O
than	O
MVT	O
's	O
minimum	O
memory	O
requirements	O
of	O
256KB	O
.	O
</s>
<s>
The	O
IBM	B-Device
System/360	I-Device
Model	I-Device
40	I-Device
was	O
developed	O
at	O
IBM	O
Hursley	O
and	O
manufactured	O
at	O
IBM	O
's	O
facilities	O
in	O
:	O
Poughkeepsie	O
,	O
U.S.	O
,	O
Mainz	O
,	O
Germany	O
;	O
and	O
Fujisawa	O
,	O
Japan	O
.	O
</s>
<s>
A	O
modified	O
Model	O
40	O
ran	O
CP-40	B-Application
,	O
the	O
ancestor	O
of	O
CP/CMS	B-Application
,	O
which	O
in	O
turn	O
was	O
the	O
progenitor	O
of	O
the	O
VM	B-Application
line	O
.	O
</s>
