<s>
Kronos	B-Device
is	O
a	O
series	O
of	O
32-bit	O
processor	O
equipped	O
printed	O
circuit	O
board	O
systems	O
,	O
and	O
the	O
workstations	B-Device
based	O
thereon	O
,	O
of	O
a	O
proprietary	B-Device
hardware	I-Device
architecture	O
developed	O
in	O
the	O
mid-1980s	O
in	O
Akademgorodok	O
,	O
a	O
research	O
city	O
in	O
Siberia	B-Application
,	O
by	O
the	O
Academy	O
of	O
Sciences	O
of	O
the	O
Soviet	O
Union	O
,	O
Siberian	O
branch	O
,	O
Novosibirsk	O
Computing	O
Center	O
,	O
Modular	B-Architecture
Asynchronous	O
Developable	O
Systems	O
(	O
MARS	O
)	O
project	O
,	O
Kronos	B-Device
Research	O
Group	O
(	O
KRG	O
)	O
.	O
</s>
<s>
In	O
1984	O
,	O
the	O
Kronos	B-Device
Research	O
Group	O
(	O
KRG	O
)	O
was	O
founded	O
by	O
four	O
students	O
of	O
the	O
Novosibirsk	O
State	O
University	O
,	O
two	O
from	O
the	O
mathematics	O
department	O
(	O
Dmitry	O
"	O
Leo	O
"	O
Kuznetsov	O
,	O
Alex	O
Nedoria	O
)	O
and	O
two	O
from	O
the	O
physics	O
department	O
(	O
Eugene	O
Tarasov	O
,	O
Vladimir	O
Vasekin	O
)	O
.	O
</s>
<s>
In	O
1985	O
,	O
the	O
group	O
joined	O
the	O
Russian	O
fifth	B-Device
generation	I-Device
computer	I-Device
project	O
START	O
,	O
in	O
which	O
Kronos	B-Device
became	O
a	O
platform	O
for	O
developing	O
multiprocessor	O
reconfigurable	O
Modular	B-Architecture
Asynchronous	O
Developable	O
Systems	O
(	O
MARS	O
)	O
,	O
and	O
played	O
a	O
lead	O
role	O
in	O
developing	O
the	O
first	O
Russian	O
full	O
32-bit	O
workstation	B-Device
and	O
its	O
software	O
.	O
</s>
<s>
During	O
the	O
post-START	O
years	O
(	O
1988	O
–	O
1991	O
)	O
,	O
several	O
Russian	O
industrial	O
organizations	O
expressed	O
interest	O
in	O
continuing	O
the	O
Kronos	B-Device
development	O
and	O
some	O
had	O
been	O
involved	O
in	O
facilitating	O
the	O
construction	O
of	O
Kronos	B-Device
and	O
MARS	O
prototypes	O
,	O
including	O
the	O
design	O
of	O
a	O
Kronos-on-chip	O
.	O
</s>
<s>
However	O
,	O
changing	O
funding	O
levels	O
and	O
the	O
chaotic	O
economic	O
situation	O
during	O
perestroika	B-Application
kept	O
those	O
plans	O
from	O
being	O
realized	O
.	O
</s>
<s>
The	O
Kronos	B-Device
instruction	B-General_Concept
set	I-General_Concept
architecture	I-General_Concept
was	O
based	O
on	O
Niklaus	O
Wirth	O
's	O
Modula-2	B-Language
workstation	B-Device
Lilith	B-Device
,	O
developed	O
at	O
the	O
Swiss	O
Federal	O
Institute	O
of	O
Technology	O
(	O
ETH	O
Zurich	O
)	O
of	O
Zurich	O
Switzerland	O
,	O
which	O
in	O
turn	O
was	O
inspired	O
by	O
the	O
Xerox	B-Device
Alto	I-Device
developed	O
at	O
Xerox	O
PARC	O
.	O
</s>
<s>
The	O
Modula-2-based	O
Kronos	B-Device
was	O
quite	O
amenable	O
to	O
the	O
basic	O
principles	O
of	O
MARS	O
,	O
as	O
Modula-2	B-Language
is	O
fundamentally	O
modular	B-Architecture
,	O
allowing	O
programs	O
to	O
be	O
partitioned	O
into	O
units	O
with	O
relatively	O
well	O
defined	O
interfaces	O
.	O
</s>
<s>
These	O
interfaces	O
supported	O
separate	O
compiling	O
of	O
modules	B-Architecture
,	O
and	O
separating	O
of	O
module	B-Architecture
specifications	O
from	O
their	O
implementation	O
.	O
</s>
<s>
The	O
primary	O
difference	O
between	O
Lilith	B-Device
and	O
Kronos	B-Device
was	O
that	O
the	O
processor	O
of	O
Lilith	B-Device
was	O
16-bit	B-Device
,	O
while	O
Kronos	B-Device
was	O
32-bit	O
and	O
incorporated	O
several	O
extensions	O
to	O
the	O
instruction	B-General_Concept
set	I-General_Concept
to	O
accommodate	O
the	O
inter-processor	O
communication	O
needed	O
in	O
MARS	O
.	O
</s>
<s>
Kronos	B-Device
satisfied	O
many	O
aspects	O
of	O
the	O
reduced	B-Architecture
instruction	I-Architecture
set	I-Architecture
computer	I-Architecture
(	O
RISC	B-Architecture
)	O
design	O
,	O
although	O
it	O
was	O
not	O
pure	O
RISC	B-Architecture
:	O
the	O
evaluation	O
stack	O
was	O
used	O
to	O
evaluate	O
expressions	O
and	O
to	O
hold	O
parameters	O
for	O
procedure	O
calls	O
.	O
</s>
<s>
Since	O
most	O
executed	O
instructions	O
were	O
encoded	O
in	O
a	O
single	O
byte	O
,	O
the	O
object	O
code	O
for	O
Kronos	B-Device
was	O
very	O
compact	O
.	O
</s>
<s>
Although	O
Kronos	B-Device
was	O
a	O
proprietary	B-Application
processor	O
,	O
it	O
was	O
well	O
suited	O
to	O
applications	O
which	O
were	O
sensitive	O
to	O
high	O
programmability	O
rather	O
than	O
to	O
software	O
compatibility	O
.	O
</s>
<s>
Modula-2	B-Language
was	O
then	O
a	O
perfect	O
language	O
for	O
this	O
purpose	O
,	O
and	O
Kronos	B-Device
was	O
a	O
perfect	O
processor	O
to	O
effectively	O
run	O
the	O
Modula-2	B-Language
software	O
.	O
</s>
<s>
An	O
advanced	O
version	O
of	O
Kronos	B-Device
was	O
based	O
on	O
a	O
32-bit	O
stack-type	O
КА1845ВМ1	O
processor	O
,	O
КА1845ВС1	O
data	O
processing	O
unit	O
,	O
and	O
УУП	O
memory	O
control	O
unit	O
.	O
</s>
<s>
had	O
246	O
commands	O
,	O
which	O
allowed	O
supporting	O
Modula-2	B-Language
language	I-Language
.	O
</s>
<s>
The	O
Kronos	B-Device
software	O
included	O
:	O
</s>
<s>
The	O
Kronos	B-Device
workstation	B-Device
includes	O
an	O
operating	B-General_Concept
system	I-General_Concept
named	O
Excelsior	O
,	O
developed	O
by	O
the	O
Kronos	B-Device
Research	O
Group	O
(	O
KRG	O
)	O
.	O
</s>
<s>
It	O
is	O
a	O
single	O
user	O
system	O
based	O
on	O
Modula-2	B-Language
modules	B-Architecture
.	O
</s>
<s>
In	O
design	O
,	O
it	O
is	O
similar	O
to	O
the	O
OS	O
Medos-2	O
,	O
developed	O
for	O
the	O
Lilith	B-Device
workstation	B-Device
,	O
at	O
ETH	O
Zurich	O
,	O
by	O
Svend	O
Erik	O
Knudsen	O
with	O
advice	O
from	O
Niklaus	O
Wirth	O
.	O
</s>
