Tuesday, July 07, 2009

Lunar Lander Computer

As we approach the 40th anniverary of the Apollo 11 mission, BBC 2 and BBC 4 are putting on loads of programmes to celebrate this event. The best has been 'Sky at Night - A Night to Remember' - superb! I have bought lots of books, a DVD and even a copy of the 'Daily Mirror' on July 20th 1969.

Back in the 1980's I swopped my Belcom Liner 2 for a Sharp 4 bit handheld computer with an LCD display... my first ever computer! This little beast was probably equivalent to the computer used in Lunar Landing Module (LEM) The computer used BASIC programming and ran simple and complex routines in BASIC.

I actually wrote a BASIC programme for landing a Lunar Module on the Moon. I took the calculation routine from a magazine, but wrote all rest and it worked! You had to enter the thrust, check your height and fuel and land on the Moon.
A couple of years later I adapted the programme and wrote some graphics to play the game in real time on a Sinclair Spectrum computer. The Lunar Module separated from the orbiting command module and you had to land visually with the graphics on screen.

Gosh ... I couldn't write a programme like this again any more!

I know that I had a print out of the software on silver heat sensitive paper in a roll ... I wonder where it is?

Sharp PC-1210 Pocket Computer

Display - 24-digit alphanumeric dot matrix Liquid Crystal Display, with yellow filter.In calculator mode it can display in scientific format 10 digits mantissa and 2 digits exponent.
Functions - Calculator and 400 step BASIC language programmable computer.Up to 50 Flexible memories (shared with program memory).Battery back-up of CMOS memory.A cassette recorder can be connected using an adapter cradle, allowing programs to be saved to audio cassettes. Also a printer & and cassette adapter was available, see photograph below, thus providing the full needs of a pocket computer.
Power supply - 3x Silver oxide button cells. The power consumption is 0.009 watts.
Semiconductors - CMOS LSI, including:
Two CPUs (Central Processing Units):
CPU 1 - SC43157.
CPU 2 - SC43158.
One TC5514P, 4 K-bit RAM.
Size 175 x 70 x 17 mm (6.9" x 2.75" x 0.7").
Introduced - 1980.
Made in Japan.

The Apollo guidance computer (AGC) with the Display / Keyboard (DSky)

Now compare this with the specs of the Lunar Landing Module Computer ... interesting reading!


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