(HP-65) RR-Model Speed

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An extract from A Speed Computer, NMRA Bulletin (vol-42 iss-8), MAR 1977, pg. 67

"   Many model railroaders do their yard switching at a scale
speed that could win the pole at the Indy 500. It's not that
they don't care, it's just that measuring scale speed is a
pest. But a programmable pocket calculator like the Hewlett-
Packard HP-65 can …
…
   If you own an HP-65 calculator use this program …
…
   If you don't own a calculator use this graph … "

BEST!
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