Welcome to Sri Lanka Royal Collage Crest
Me

Website of Capt Priyantha A Dias

Royal Crest

Interest in Computers

Skip Navigation LinksHome >>Interests >>Computers
Skip Navigation Links.

E-mail Me

View Priyantha Dias's profile on LinkedIn

View Priyantha Dias's Profile at Spoke

Sri Lanka Top Sites
Sri Lanka Top Sites
The HP-71B My love with computers started in 1985 with this HP-71 hand-held wonder. It had Basic Language and was a super number cruncher.

I accidentally bumped into a broucher of this machine in the ship's office; though never understood much of what was in it regards the technical details. So I went looking for the shop in Singapore and spent 2 hours pondering if a month's salary was worthwhile investing into this something so small. Finally I bought it.

I spent one night with it trying to figure out what it could do... It came with a huge Basic Manual and Keyword Reference. By next morning I could add two numbers... then input some names and get them out...

By the time the ship went from Singapore to Yemen I had a very complex program to calculate Stability of my ship Lanka Srimani. At the time that program took nearly all the memory of the HP-71. Years later I wrote the same program with only 21 lines without counting the DATA statements.

What was so unique of the HP-71B  was its astronomical numerical range and the ability to handle and continue with processing the math exceptions of division by zero or multiplications by infinity.

This particaularly came in handy when programming Radar Plotting and Sight Reduction as it is common that a variable will result in division by Sin 0 or Cos 90... or the multiplication by Tan 90...

All my initial programming and learning was done with the HP-71B but it had it's drawbacks... It did not have a storage medium except an optional magnetic card reader... everytime one changes the batteries the programs had to be re-installed...

...and the interfaces required for monitor display and a printer were prohibitively expensive.

So I decided to move on to the next cheap machine; the  Sinclair QL

 

A remarkable man was Sir Clive Sinclair . His inventions have been legendry in the British History but his business accumen fell far short of his cousins in US.

He invented the small machine-code ZX-81, the Spectrum and then the QL  

The Sinclair QL

 The QL was indeed a quantum leap in technology using the Motorolla 68008 16/32 bit processor with multi-purpose registers unlike the Intel 8086, in vogue at the time which had dedicated data and address registers.

The storage medium was a set of dual microdrives and it came with four software packages; Quill, Abacus, Archive and Easel, the forerunner of today's MS Office.

One need not have a monitor; this machine could be connected to a home TV... I re-wrote all the programs in Superbasic into the QL.. now I had a large screen displaying data, also plenty of graphics...

I also wrote a database to handle the ship's stores, a graphics program to handle bay planning and many other applications to make my life easier...

What I needed next was a printer to get all these data on record. I got myself an Epson dot matrx printer from Singapore.

Unlike today where you simply insert the driver disk and install a printer, at the time one needed to write code to print what you need and the way you needed it printed.

This calls for knowing <Esc> codes and CTRL characters. This by itself was another challenge.

Anyway, by 1987 a whole new breed of IBM compatible machines were on the market, notably the Intel 8088 for which I went next...

Read More...

 

Links








Sinhalaya.Com - The True Sri Lankan Web Network To All...

Add url directory
Changing LINKS>Changing LINKS