OVER 2 YOU, 067 (12/02/02)

TRAINING AID

I am looking for a train driver simulation program; I know nothing about them and would appreciate any expert advice or recommendations.

Sophie Walker, Kenya

Probably the best is Mr. Macoy's Bosso View Express, a Japanese freeware program. It is regarded as very realistic, even incorporating 'cab sway'. A good starting point is the BVE Helper website at: http://members.aol.com/bvehelper/

Microsoft also has a commercially available program called Train Simulator, more details can be found at: http://www.microsoft.com/games/trainsim/

Happy driving!
Tony Morgan,

CALCULATORS IN SPACE

I’ve often read that there is more computing power in a modern pocket calculator than was available in the Apollo spacecraft that landed on the moon. Is that really true? If so, does anyone know the specification of those early computers, or relative speed, compared with today’s desktop PCs?

R. Silver, Huddersfield

It’s worth having a look at an article written by Fred H Martin who was the Deputy Director of the Mission Development Group at MIT, at the time of the Apollo missions. (see:    http://www.hq.nasa.gov/office/pao/ History/alsj/a11/a11.1201-fm.html) According to Fred Martin the on-board Apollo Guidance Computer (AGC) was housed in a box measuring around 1 cubic foot, it had 2k of 16-bit RAM and 36k of ‘rope-core’ memory, which would indeed be totally inadequate for even the humblest of today’s pocket calculators. However, perhaps the most impressive statistic is the computer’s reliability or MTBF (mean time between failure), which was determined to be 50,000 hours or about 6 years, and in fact it never did go wrong during a flight operation, clearly they weren’t using Windows for Rockets…

Denis Gerrard, Southport

A fascinating description of the Apollo Guidance Computer, along with a detailed technical specification, several photographs and personal anecdotes can be found at:

http://www.ddj.com/documents/s=1494/

ddj0006hc/0101hc001.htm

Ben Davies,

EDUCATING EXCEL

I am compiling a database of names with dates of birth and death etc. I am using Excel for compiling my family tree; it being much better suited to the task than any commercial software I've found. Unfortunately, Excel will not allow dates to be shown pre-1900 in the database, so I am unable to calculate longevity automatically. Is there any way to sidestep this to allow pre-1900 dates? If not (and I suspect that will be the case) can anyone suggest another way?
Dave Reid, via email

The following function will allow Excel to manipulate dates from 100AD to
9999AD.
Load spreadsheet containing database
Click Tools-Macro-Visual Basic Editor
Click Insert-Module
Type the following lines into the box choosing one of the two lines
commencing 'Aged =' depending on the output you require

Function Aged(Born As Range, Died As Range) As String
Dim LastBirthday, Years, Days
    LastBirthday = IIf(DateSerial(Year(0), Month(Born), Day(Born)) <
DateSerial(Year(0), Month(Died), Day(Died)), Year(Died), Year(Died) - 1)
    Years = LastBirthday - Year(Born)
    Days = DateValue(Died) - DateSerial(LastBirthday, Month(Born),
Day(Born))
    Aged = Years & " years " & Days & " days" 'eg 62 years 240 days
    Aged = Years & "." & Days                     'eg 62.240
End Function

Click File - Close to return to the spreadsheet
Now enter the dates for Born and Died in cells -  use normal windows formats
eg: 21 Jun 1666 or 21/6/1666
but do not format them as date/time leave them formatted as General
Select the cell for the age, also formatted as General
Click on the = (edit formula)
Click on the down symbol beside DATEVALUE
Click on 'more functions'
Select function 'category = user defined'
Select 'Aged' and click OK
Click in the box labelled Born
Click in the cell containing the Born date
Click in the box labelled Died
Click in the cell containing the Died date
Click OK in the box

The appearance could be any combination of those below

Born 5/7/1605 Died 1 Mar1668 Aged 62 years 240 days
Born 5 July 1605 Died 1/3/1668 Aged 62.240

Norman Wilcox,

CAN YOU HELP?

What was the first page on the Internet, and is it still there?

Des Peters, via email

I’m very pleased with the results from my new digital still camera but can anyone tell me how long pictures printed on my Canon printer are likely to last, before they fade, and is there anyway to preserve the original data indefinitely that will save it from the inevitable obsolescence of current recording media?

S. Richardson, via email

A few years ago I remember reading an article in The Telegraph about a young boy who made a windmill from a discarded bicycle dynamo. It produced enough power to run his radio and provide some light for his garden shed. Can anyone provide plans or tell me how this was done?

D. Modaher, Southall, London