Monday, October 31, 2011

The Demon Machine

Over the weekend I was reunited with the first two computers I spent extensive time programming. The Sharp MZ-80K (released in 1979) and the BBC Micro Model B (released in 1982).

Here's the BBC Micro:

with the top off you can spot that I've added my own headphone socket at the back and that this machine was upgraded with the speech synthesis module.

And I had the ROM slots maxed out with Basic II, Caretaker, and Acornsoft LISP.

And here's the Sharp MZ-80K:

Both work fine, but I was struck by my reaction to the machines. I wanted to boot them up and get programming. A little voice in each machine was speaking to me about all the unchartered lands of programs that could be written in just kilobytes of RAM. Of all the possibilities, tucked away in the Acorn MOS and the Sharp's memory.

It's the same little voice that still drives me on to write just another line of code, to perfect just another little routine. Just the other night I was dragging myself at midnight but unable to turn in until I'd got the proportional font working on this homebrew display I'm working on:

Truly, that inner voice is demonic. The seductive world inside a computer (so well captured in 1982's Tron) draws you in with just one more possibility, just a little more time. The demon voice asks that you keep going when physical strength is gone, when you know that tomorrow will come and tiredness will ruin your day. But right now, right then, the power of the machine, the power over the machine, matters more than anything.

And yet the computer is a harsh mistress. If it fails to do what you want it's because you failed. It is merely deterministic; you didn't correctly tell it what to do. As Maurice Wilkes poignantly puts it of the early days of computing:
As soon as we started programming, we found to our surprise that it wasn't as easy to get programs right as we had thought. Debugging had to be discovered. I can remember the exact instant when I realized that a large part of my life from then on was going to be spent in finding mistakes in my own programs.
The human/machine relationship is abusive. The computer tempts you with its power and possibility, then punishes you with your own failings, your own inept attempts at programming it, your own lack of knowledge. And yet you love it.

As ever Richard Feynman can be relied upon to capture the disease of computing:
“Well, Mr. Frankel, who started this program, began to suffer from the computer disease that anybody who works with computers now knows about. It's a very serious disease and it interferes completely with the work. The trouble with computers is you *play* with them. They are so wonderful. You have these switches - if it's an even number you do this, if it's an odd number you do that - and pretty soon you can do more and more elaborate things if you are clever enough, on one machine.

After a while the whole system broke down. Frankel wasn't paying any attention; he wasn't supervising anybody. The system was going very, very slowly - while he was sitting in a room figuring out how to make one tabulator automatically print arc-tangent X, and then it would start and it would print columns and then bitsi, bitsi, bitsi, and calculate the arc-tangent automatically by integrating as it went along and make a whole table in one operation.

Absolutely useless. We *had* tables of arc-tangents. But if you've ever worked with computers, you understand the disease - the *delight* in being able to see how much you can do. But he got the disease for the first time, the poor fellow who invented the thing.”
And so dear BBC Micro and Sharp MZ-80K you shall remain powered off (or at least that's what I'll tell everyone and I'll secretly fire up that LISP ROM when no one's looking and just write a little program, just one.)

Henry Kissinger has famously said that power is better than sex. Well, clearly he isn't a programmer!

PS Does anyone have a copy of the manual for the Caretaker ROM? Purely, for completeness; clearly I'm not going to actually need it :-)

Wednesday, October 05, 2011

Action this Day. Here's how to help Bletchley Park

With the wonderful news that Bletchley Park has been awarded £4.6m in funding from the Heritage Lottery Fund there's a follow up appeal. The lottery funding comes with a condition to raise £1.7m in matching funding. You can help make that happen by donating.

Bletchley Park has a donation page here. For folks in the UK a simple text message to 70070 in the form BPRK99 £x where x is the number of pounds you want to donate is a fast way to do it. It works, I just did it.

Bletchley Park matters in many ways:

1. The history of the Second World War was dramatically changed by the intellectual warriors that worked there. The most well known is, of course, Alan Turing, but Station X (as it was known) was filled with interesting, odd, intelligent characters who read the secret correspondence of the Nazis from the lowly soldier in the field to the high command.

2. Bletchley Park has a strong claim to being a big part of the computer revolution. Turing, of course, was there, but also the incredibly fast Colossus machine was built for electronic code breaking.

3. The Bletchley Park site houses Britain's National Museum of Computing and the National Radio Centre.

This money will preserve the history of the site, and enable it to grow into a real museum and attraction. Today, the sorry state of the buildings and the lack of funding for the educational aspects means that Bletchley Park is forced to turn away schools wishing to plan visits.

As the computer has now become such an important part of our lives, and as the Second World War's outcome is the foundation for modern Europe, Bletchley Park is truly worth preserving.

When Alan Turing wrote to Winston Churchill asking for help in speeding up the cracking of codes at Bletchley Park by providing more resources, Churchill wrote on the memo: "Action this day! Make sure they have all they want on extreme priority and report to me that this had been done".

Let's make sure that the current staff of Bletchley Park have what they need to make it the must see destination outside London.