<s>
Transaction	B-Language
Application	I-Language
Language	I-Language
or	O
TAL	B-Language
(	O
originally	O
"	O
Tandem	B-Language
Application	I-Language
Language	I-Language
"	O
)	O
is	O
a	O
block-structured	O
,	O
procedural	O
language	O
optimized	O
for	O
use	O
on	O
Tandem	O
hardware	O
.	O
</s>
<s>
TAL	B-Language
resembles	O
a	O
cross	O
between	O
C	B-Language
and	O
Pascal	B-Application
.	O
</s>
<s>
It	O
was	O
the	O
original	O
system	B-Language
programming	I-Language
language	I-Language
for	O
the	O
Tandem	O
CISC	B-Architecture
machines	O
,	O
which	O
had	O
no	O
assembler	O
.	O
</s>
<s>
The	O
design	O
concept	O
of	O
TAL	B-Language
,	O
an	O
evolution	O
of	O
Hewlett	O
Packard	O
's	O
SPL	B-Language
,	O
was	O
intimately	O
associated	O
and	O
optimized	O
with	O
a	O
microprogrammed	B-Device
CISC	B-Architecture
instruction	O
set	O
.	O
</s>
<s>
Each	O
TAL	B-Language
statement	O
could	O
easily	O
compile	O
into	O
a	O
sequence	O
of	O
instructions	O
that	O
manipulated	O
data	O
on	O
a	O
transient	O
floating	O
register	O
stack	O
.	O
</s>
<s>
The	O
register	O
stack	O
itself	O
floated	O
at	O
the	O
crest	O
of	O
the	O
program	O
's	O
memory	B-General_Concept
allocation	I-General_Concept
and	I-General_Concept
call	I-General_Concept
stack	I-General_Concept
.	O
</s>
<s>
The	O
language	O
itself	O
has	O
the	O
appearance	O
of	O
ALGOL	B-Language
or	O
Pascal	B-Application
,	O
with	O
BEGIN	O
and	O
END	O
statements	O
.	O
</s>
<s>
However	O
,	O
its	O
semantics	O
are	O
far	O
more	O
like	O
C	B-Language
.	O
It	O
does	O
not	O
permit	O
indefinite	O
levels	O
of	O
procedure	O
nesting	O
,	O
it	O
does	O
not	O
pass	O
complex	O
structured	O
arguments	O
by	O
value	O
,	O
and	O
it	O
does	O
not	O
strictly	O
type	O
most	O
variable	O
references	O
.	O
</s>
<s>
Programming	O
techniques	O
are	O
much	O
like	O
C	B-Language
using	O
pointers	O
to	O
structures	O
,	O
occasional	O
overlays	O
,	O
deliberate	O
string	O
handling	O
and	O
casts	O
when	O
appropriate	O
.	O
</s>
<s>
Microcode	B-Device
level	O
support	O
was	O
available	O
for	O
null	O
terminated	O
character	O
strings	O
.	O
</s>
<s>
Originally	O
the	O
Tandem	O
NonStop	O
operating	B-General_Concept
system	I-General_Concept
was	O
written	O
in	O
TAL	B-Language
.	O
</s>
<s>
Recently	O
much	O
of	O
it	O
has	O
been	O
rewritten	O
in	O
C	B-Language
and	O
TAL	B-Language
has	O
been	O
deprecated	O
for	O
new	O
development	O
.	O
</s>
<s>
In	O
the	O
migration	O
from	O
CISC	B-Architecture
to	O
RISC	O
TAL	B-Language
was	O
updated/replaced	O
with	O
pTAL	O
-	O
compilers	O
allowed	O
TAL	B-Language
to	O
be	O
accelerated/re	O
-compiled	O
into	O
Native	O
RISC	O
Applications	O
.	O
</s>
<s>
In	O
the	O
current	O
migration	O
from	O
RISC	O
to	O
Intel	O
Itanium	O
2	O
TAL	B-Language
and	O
pTAL	O
has	O
been	O
replaced	O
with	O
epTAL	O
,	O
again	O
-	O
compilers	O
allow	O
TAL	B-Language
and	O
pTAL	O
code	O
to	O
be	O
accelerated/re	O
-compiled	O
into	O
native	O
Itanium	O
Applications	O
.	O
</s>
