Honeywell 400 Series Hardware Manual page 86

Timing Considerations
Approximately 600 milliseconds are required for the punching of each card except the
first. On each card there is a data transfer time of 24.0 milliseconds for each row except
the 12-row. Each row has a punching time of 14.4 milliseconds. Following this, there
are 4.4 milliseconds available for brush reading the corresponding row of the preceding card.
For each row except the 9-row, data transfer for the next row may begin during the 4.4
millisecond reading time; however, of the resulting total of 28. 4 milliseconds, only the row
punch instruction and the first data character may be received during the 4. 4-millisecond
reading time.
After the last row of the card (row 9) is punched and row 9 of the preceding card is read,
there are 43 milliseconds in which a punch instruction may be received for row 12 of the next
card if punchmg is tobemaintained at the rate of 100 cards per minute. If the new instruction
is received during this 43 -millisecond interval, there are approximately 66 additional
milliseconds available
(instead of 24.4 ms) for the transfer of punch data for the first
row. If a row punch instruction is not received during this period, there is a 7-card-per-
minute reduction in the overall card punching rate. There will be an additional 7-card-
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