4 ms·
It is too late for me to edit my other comment, but IBM offered ratchet wheels with double the normal number of teeth (54 rather than 27), providing quarter-lin
by kps 4y ago
It is too late for me to edit my other comment, but IBM offered ratchet wheels with double the normal number of teeth (54 rather than 27), providing quarter-line motion, for the Selectric.
p11 https://bitsavers.org/pdf/ibm/typewriter/selectric/PCE-008-1_Parts_Catalog_Selectric_Model_71x_72x_Aug70.pdf https://bitsavers.org/pdf/ibm/typewriter/selectric/PCE-008-1...
- jsmith45 4y agoOk that certainly seems to explain the vertical spacing. Was there something that would allow for the the fancier horizontal resolution tricks?
- kps 4y agoSome other comments¹ have said that some Selectrics had a half-space control, so that would provide 1/24″ horizontally. I think that's the finest in the paper, unless I've missed a case. ¹ e.g. https://news.ycombinator.com/item?id=35177786 https://news.ycombinator.com/item?id=35177786