Re: Byte Addressability And Beyond

On Thu, 2 May 2024 01:57:53 -0000 (UTC), John Levine wrote:

According to Lawrence D'Oliveiro  <ldo@nz.invalid>:
>

Though I do recall, the 1401 didn’t have a “word length” as such:
it was a “character”-based machine. For example, it could do
arbitrary-precision arithmetic--it just kept processing digits
until it hit a special end-of-data marker--but obviously this only
worked for (fixed-point) addition and subtraction. The machine had
no hardware support for multiplication or division. Or
floating-point, for that matter.

 
You may be confusing it with the 1620.

The 1401 was the one with the “word-mark” bit that I was thinking of,
which was set to 1 in the final (highest-order) digit of a number.

The 1620 looks like it did it in a different way, with a separate end-of-
number character.

The “Guide to 1401 Programming” I’m looking at (from 1961) makes no
mention of multiplication or division.