Re: ancient floating point, These days what percentage of a CPU's work involves doing arithmetic computations

Philipp Klaus Krause <>
Fri, 16 Jul 2021 18:31:05 +0200

          From comp.compilers

Related articles
| List of all articles for this month |

From: Philipp Klaus Krause <>
Newsgroups: comp.compilers
Date: Fri, 16 Jul 2021 18:31:05 +0200
Organization: Compilers Central
References: 21-07-004 21-07-012
Injection-Info:; posting-host=""; logging-data="20240"; mail-complaints-to=""
Keywords: architecture, history, comment
Posted-Date: 16 Jul 2021 12:41:00 EDT
Content-Language: en-US
In-Reply-To: 21-07-012

>> any floating point hardware until the IBM 704 in 1954
> It is said that the Z3 (1941) was designed with floating-point.
> […]
> [I don't think the Z3 was ever built other than as a much later
> retrocomputing project.  Von Neumann apparently considered floating
> point for the EDVAC and IAS machine but rejected it as too complex
> and anyway doing the scaling in software was easy, which it
> probably was if you were Von Neumann. -John]

AFAIK, the Z1 (built in 1939, working but like many early computers not
very reliable, working, destroyed 1944, working replica in a museum in
Berlin), the Z3 (built in 1941, destroyed 1943, working replica in a
museum in Hünfeld), the Z4 (built 1945, in use until 1959, original in a
museum in Munich) and the Z5 (built 1953, in use until 1958, current
whereabouts unknown, probably scrapped) all have binary floating-point.

[I've seen the replica Z1, which is entirely mechanical. I didn't realize
it used floating point. -John]

Post a followup to this message

Return to the comp.compilers page.
Search the comp.compilers archives again.