re: Ada and robots

[John Howard <jhoward@sky.net>]

Adding comp.lang.ada

On Sat, 28 Jun 1997 puk@tc.umn.edu wrote:
> I don't understand how Ada got it's undeserved reputation
> of inadequate low-level interfacing capabilities. My guess
> is that it is somehow related to the C and assembly culture
> that says low-level interface code has to look a certain
> way, i.e. concise statements such as: r = (x << 2) && 8
> I have heard many a software person say this is how they can
> get to the "bare metal".

My guess is novices starting to program during the 1980's and accepting 
hearsay about early Ada systems as the gospel truth from then until
doomsday. (Byte magazine was very influential back then. Many people would 
also rely on the ads to see what was happening. Ads for Ada dwindled
because the readership was mostly PC oriented on miniscule systems. The
lasting impression was Ada was big, slow, overly protective, overly 
priced, and overkill for what you wanted to do.)

Justifiably some of the hearsay was true about those old Ada systems. But 
now there is a *new and improved* Ada standardized in 1995. With Ada you 
can usually code in assembler or use intrinsics when you have to. And
using Ada protected types with multitasking on the bare metal has the 
potential to provide speed and efficiency that even C can't match. 
Although a custom RTOS (designed with protected types in mind) + C
solution would be able to offer similar benefits.

www.adahome.com to see for yourself

> The reality of the situation is that the "bare metal" can be
> synthesized through a Hardware Description Language such as VHDL,
> which in fact has a very similar syntactical representation to Ada.
> Whole processor cores for devices such as the 8051 can be purchased
> as VHDL source code.
>
> A quiz: Which of the following package specs is Ada and which is VHDL?
>
> -- Language X
> library Bit_Level;
> use Bit_Level.all;
> package Register_File is
>
>    type R_File is array (Reg'Range) of Bit;
> 
> end Register_File;
> 
> -- Language Y
> with Bit_Level;
> use Bit_Level;
> package Register_File is
>
>    type R_File is array (Reg'Range) of Bit;
>
> end Register_File;

Good point.

------------------------------------------------------------------------
-- John Howard <jhoward@sky.net>               -- Team Ada  Team OS/2 --