16 Aug
2008
16 Aug
'08
8:36 a.m.
On 16 Aug 2008 at 10:36, Christian Corti wrote:
One has to be careful with IBM's terminology.
Opcodes are called
microinstructions, and they are executed ("interpreted") by the microcode
(i.e. the processor). So microcode in IBM's terminology is always
interpreted by the processor (what else should a processor do?). This
doesn't mean that there must be an additional interpreter written in
machine code that interpretes the op codes. However this is what IBM did
e.g. with the 5110 and its built in System/3 and System/360 interpreters
which are written in PALM microinstructions which in turn is "interpreted"
by the processor. So either IBM did something similar for the 4702, or
the 4702 processor directly executes FCL opcodes.
Sometimes it pays to read people's resum?s. One such that I ran
across talked about coding in both 4700 FCL and 4700 assembler.
Unless the writer was "padding" things, that might indicate that FCL
was just a language, not a macrocode implementation.
Cheers,
Chuck