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From: "Corey Ashford" <yeroca7@rocketmail.com>
Subject: Re: question re Ada equivalent of C function
Date: 1998/02/21
Message-ID: <6cnj5d$bjq$1@usenet.rational.com>#1/1
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References: <34EEFF9C.1D01FA5D@stellar1.com>
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Organization: Rational Software
Newsgroups: comp.lang.ada
Date: 1998-02-21T00:00:00+00:00
List-Id: <comp.lang.ada>



David Fisher wrote in message <34EEFF9C.1D01FA5D@stellar1.com>...
>Sorry if this is a bit basic, but learning Ada on one's own can be, er,
>challenging.
>
>What are the Ada equivalents of the C functions, inp and outp, used to
>read a byte from or send one to a memory address?
>
>Thanks!
>
>David Fisher
>Fisher Research Corporation
>

There are a number of ways to do this in Ada.  Here's one fairly simple one:

with unchecked_conversion;
with system;

type byte is mod 2*8;
type byte_access is access byte;
function to_byte_access is new unchecked_conversion(system.address,
byte_access);

function inp(addr: system.address) return byte is
begin
    return to_byte_access(addr).all;
end inp;

procedure outp(addr: system.address; value: byte) is
begin
    to_byte_access(addr).all := value;
end outp;