[pdp7-unix] ald

Phil Budne phil at ultimate.com
Mon Oct 21 10:23:50 AEST 2019


Tom wrote:
> Does anyone know what "ald" does?

Looks to me like it's reading binary punched cards.

It gets some card read-related system addresses,
and defines an I/O instruction:

crsb = 0706744

which is defined on page 96 of
http://www.bitsavers.org/pdf/dec/pdp7/F-75_PDP-7userHbk_Jun65.pdf

to select card reader "column binary" mode, reading the rows of each
column in as a 12 bit number.

p


More information about the pdp7-unix mailing list