Path: ...!weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: David Brown <david.brown@hesbynett.no>
Newsgroups: comp.lang.c
Subject: Re: What is your opinion about unsigned int u = -2 ?
Date: Thu, 8 Aug 2024 19:47:14 +0200
Organization: A noiseless patient Spider
Lines: 18
Message-ID: <v930b2$4v1a$1@dont-email.me>
References: <v8dfo9$1k7cg$1@dont-email.me>
 <pan$d2c8a$8c54ac9f$29a202e0$12c6ce86@invalid.invalid>
 <87bk2cecan.fsf@bsb.me.uk> <v8inds$2qpqh$1@dont-email.me>
 <v8iqnr$7l3c$1@news.xmission.com>
 <v8oha0$6935$2@raubtier-asyl.eternal-september.org>
 <v91157$3eui3$2@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Thu, 08 Aug 2024 19:47:15 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="ce5b9e6be3d3d9420cd4b6f4d8fd36d7";
	logging-data="162858"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX194+ogtlAZKAGAHlDXcaX2eJ2ghtI4pq+Q="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:/B+lMLLigs9d+tD5XfiHW5vuGRA=
Content-Language: en-GB, nb-NO
In-Reply-To: <v91157$3eui3$2@dont-email.me>
Bytes: 2083

On 08/08/2024 01:48, Lawrence D'Oliveiro wrote:
> On Sun, 4 Aug 2024 20:29:21 +0200, Bonita Montero wrote:
> 
>> Since the mid of the 70s all new machines work all with 2s complement.
>> There will be never computers with different notations since the 2s
>> complement makes the circuit design easier.
> 
> This may be hard to believe, but I think in the early days 2s-complement
> arithmetic was seen as something exotic, like advanced mathematics or
> something. To some, sign-magnitude seemed more “intuitive”.
> 
> As for ones-complement ... I don’t know to explain that.

Think about negating a value.  For two's complement, that means 
inverting each bit and then adding 1.  For sign-magnitude, you invert 
the sign bit.  For ones' complement, you invert each bit.