Re: Not a typewriter

John Kodis (kodis@mail630.gsfc.nasa.gov)
Mon, 14 May 2001 10:31:48 -0400


On Sun, May 13, 2001 at 09:03:30PM -0400, Horst von Brand wrote:

> The old C compiler/old Unix linker guaranteed 6 chars in an external symbol
> name only, and C functions got an underscore prepended: _creat. I guess
> this is the reason for this wart. As to why 6 chars only, I'd guess some
> data structure in the linker was laid out that way. Machines had a few
> dozen Kbs of RAM then, space was precious.

I recall that RSX-11 and a few other series of early DEC operating
systems stored linker symbols in a "RAD50" encoding scheme which
allowed 6 chararacters to be crammed into a 32-bit "long word". I
suspect that this is where the limitation originated.

-- 
John Kodis <kodis@acm.org>
Phone: 301-286-7376
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