Posted by John Wilson on February 08, 2005 at 09:11:03 from 202.154.157.202 user hugo.
In Reply to: Re: Rainfall posted by Peter H on February 07, 2005 at 21:11:37:
I recall HP or Hewlett Packard desk-top calculators in the 1970s in the New Zealand Post Office - in the Telecommunications section that became Telecom New Zealand when it was reorganised & privatised.
A HP Model 30 used eight inch floppy disks, and a HP Model 10 used rectangular magnetic cards about four or five inches long by one + inches wide - pity I did not keep one of either as a memento!
While the Model 30 was programmable, the Model 10 using cards was more limited, although I could calculate both the loop resistance and transmission loss of local telephone circuits of mixed gauges which was useful. With long rural buried cable, the British step switching equipment used then reached the thousand ohm signalling limit quite quickly; later NEC crossbar equipment from Japan had a 1500 ohm (I think) signalling limit, although by the time the loop got to 1200 ohms the 10 db transmission limit to the local exchange was reached (unless loading coils - the usual answer - was used, or amplification).
PS: I recall the story that when Messrs Hewlett & Packard made their first instrument (in a garage), was it a ‘scope?, it was called the Model 231 or similar, as they did not think that calling it Model No 1 would impress!