IBM 1620 invalid character symbol

[Ken Whistler via Unicode]

Leo,


On 9/26/2017 9:00 PM, Leo Broukhis via Unicode wrote:
> The next time I'm at the Mountain View CHM, I'll try to ask. However, 
> assuming it was an overstrike of an X and an I, then where does the 
> "Eris"-like glyph come from? Was there ever an IBM font with a 
> double-semicircular X like )( ?
>

The reason for focusing on the hardware is that during operation of an 
IBM 1620, that is what would have been printed on paper by the actual 
machines, and what people would have seen  in core dumps, or whatever.

The question of what was printed in the *documentation* is a different 
issue, really. That involves figuring out what the editors/typesetters 
of the manuals were doing to represent a symbol generated by 
overstriking by the hardware, for which they had no convenient type to 
use, by whatever word processing and printing technology they were using 
circa 1959. I suspect that both the "Zhe"-like glyph and the "Eris"-like 
glyph we have seen in the printed copies of the manual are themselves 
typesetter substituted glyphs for whatever the 1620 tofu glyph was that 
they were trying to represent. Where they got those glyphs, I dunno -- 
and it might be pretty difficult to track down, because almost all the 
folks who would have known what IBM manual typesetting practices were 
circa 1959 will have passed on by now.

I don't know of any *standard* IBM glyph for this "Eris"-like thingie 
seen in the scanned bit of manual that started this thread -- but my 
documentation is from the 1980's era listings of standardized glyph 
identifiers. Who knows what was going on circa 1959, which predated most 
of the IBM efforts to standardize large glyph sets and large numbers of 
character sets? Back then, "fonts" consisted of what were cast on the 
typebars of typewriters, or on the strikers of line printers, or the 
physical type that typesetters used.

Look at the archival pictures of the IBM 1620. Do you see any display 
font anywhere? That console is a Star-Trek style computer console -- all 
register lights and bit switches and rows of power station style 
light-up buttons. Not a font anywhere. The only font on that machine can 
be found by feeling the key strikers in the typewriter.

--Ken