IBM 3800 maxed out at 12,423 lines per minute, not 20,000
The 3800 printed at 20 inches per second. It could print pages sideways, where the paper was landscape mode, and so was the type, so it looked like portrait mode, after the continuous paper was burst into separate sheets, and trimmed of its sprocket holes into 8.5 by 11 inch sheets. That 12,423 line per minute number comes from
(11 inches of print lines per page )
* (8 lines per inch)
* (60 seconds per minute)
* (20 inches per second)
/ (8.5 inches per page)
= 12423.5 lines per minute.
A major reduction on throughput was how long it took the operator to change a box of paper. It could print a box in about 15 minutes, but took another 5 to replace it. The solution was to use a non-IBM paper handler. It held a very large roll of paper outside the printer, with rollers to pass the paper into the printer and twist it around to feed correctly.
Biting the hand that feeds IT
