Sunday, 3 April 2022

Emulating the past

“It’s no use going back to who I was yesterday, because I was a different person then”
Lewis Carroll

For so long, now, it's very fashionable to go back to how things were, that retro is almost passé.

It's computing that makes it all possible, of course. Computers today are so powerful that they can emulate older computers even faster than full speed.

Even in my lifetime, new computers became so fast that they weren't slow enough to properly run some of the older programs that they were supposedly compatible with. That's always fun telling the user "It's because your computer is so powerful it crashed the program". It's quite something to watch them dilute their own frustration with a mingling of pride and awe.

My history with computers started as a pre-teenage child when I traded a pair of opera glasses (that I had got from a friend whose dad ran a waste processing business) with a school teacher, to get an old electric school bell. I used to wake up at night from realistic dreams of the electric shocks that I inflicted on myself during the day.

Around the same time, my dad brought a bunch of old Bakelite telephones home from where he worked. I'm not sure what he did with them, but when he'd finished, I knew enough to fix them up with my old train transformer and make some kind of an intercom system (incurably suffused with a 50hz hum loud enough to give you a headache).

It went on from there. What pocket money I didn't spend on sweets I'd spend on the Maplin Electronics catalog and look at all the things I could build, and all the things I could build them with, if only I wouldn't spend all my money on sweets.

And that was the problem. Apart from the odd FM transmitter, I didn't build very much because electronics is an expensive hobby - all those parts to buy. I used to get by filing components from old transistor radio circuit boards before I was given leave to use the antique soldering iron. I still have a scar on my wrist from that!

But one day as I was walking home from school along the main road, that we all traveled, I heard some crazy talk, and that made all the difference.

My brother was talking to a friend about a computer program that he had written at computer club, which made a man walk across the screen, getting lower and lower, and leaving some dots behind him. It sounded fantastic, but yet his ideas intrigued to me.

I don't know what I had been doing instead of going to the computer club, but the very next time I did go to the computer club and asked the computer teacher:

Please write me a program that makes a man walk across the screen getting lower and lower and tell me how it does what it does.

Even now I am as impressed by my ability to synthesize that request as I am of my ability to understand the program.

The program is something like this (Try it on the Beeb Emulator at https://bbc.godbolt.org/):
10 CLS
20 FOR Y=0 T0 25
30 FOR X=0 T0 40
40 PRINT TAB(X,Y) "*";
50 PRINT TAB(X,Y);
60 A$=INKEY$(10)
70 PRINT TAB(X,Y) " ";
80 NEXT X
90 NEXT Y
The teacher explained how it worked but it was pretty obvious. He was a kind and good teacher, so rather than answer my questions all night, he gave me the user programming guide (for those were the days when the users did the programming).


One misspent youth later, including the notable event of being dragged out of the computer room by the invigilator so that I could sit what was left of my french exam, I had written the following computer software:
  1. The school email program (BBC Micro, on the eNet network system)
  2. Decode morse code (including punctuation) (Sinclair ZX81)
  3. Various programming tools (music output, read-data-&-restore) (Sinclair ZX81)
  4. Database (Amstrad CPC6128) where I learned that adults will answer personal questions posed by a child if a computer is used.
  5. 3-player personal computer implementation of electronic game Detective Shoestring originally by Grandstand, which involved a cardboard separator on the screen, and added a helpful detectives dog as the third player. (Amstrad CPC6128)
  6. Much much more, and I also learned the futility of adding "-on-a-computer" to various other specialist tasks of the time. My attempt at scenery design on a BBC micro was doomed.
I think I only paid for 1 computer, my ZX81, and the seller gave me many a sleepless Friday night as he repeatedly forgot to bring it on Saturday each week. Christmas eve excitement was nothing to getting my first computer. My Dad then bought me a portable TV to stop me hogging the one in the front room.

Through kindness and good fortune I was lent/borrowed/given the following: 
  • ZX Spectrum 48K
  • Amstrad CPC6128
  • TRS80 II with dual disk drive
  • 80286 with 2MB RAM and Hercules Graphics Card
  • 397SX16 with 4MB
After which I was able to buy a 386DX40 motherboard and 4MB RAM with Crystal sound card, and a second hand 540MB hard disk for £40

Such glorious memories.

And now -- the computers of the past return in the form of an emulator. All of them. Most of them will even run in a web browser.

I've installed some of them, but mostly I just look and stare in a daze.

What do I want to make it do? 

Nothing. I did it all already. 

I can't go back to my childhood, I'm not a child anymore.

I seek not to follow in my footsteps of old, I attained those things I sought.

Saturday, 2 April 2022

Frozen Lemons

“When life gives you lemons, make lemonade or freeze them and throw them at the people that are making your life difficult”
- Unknown

Blessed children skip along scattering sunshine and petals wherever they go, delighting to bless each life they touch for good.

Other children have never heard of such a thing. Being occupied with weightier matters, they receive their parents' duty and love as a matter of course, and get on with their own obsessive labours while the day yet remains.

My brother and I had mastered all of the necessary arts for young children and made it our labour to engage these daily for our enjoyment and delight. 

We knew the secrets of overlapping lego brings to bring strength to a wall. 

We could put a water pistol to hours of judicious use until the inevitable blister on our trigger finger burst and ripped open, but we could also use a knife to split open a water pistol to extract the pump mechanism to serve as the essential core of a fire engine yet to be built.

We knew the secrets of a beach ball, both to inflate it and deflate it, despite the anti-deflation mechanism.

We could slide down the stairs in our sleeping bags without injury but we could also climb up the green and yellow "beanstalk" blanket which hung from the balustrade above the bottom of the stairs. 

Life was worth living, and we lived it with rarely a thought for those who made it so worthwhile.

One long summer day ended too soon. I don't know if we had been sent to bed early, but if so, we probably deserved it. We might have accepted this, but it wasn't dark, and one of us saw a water pistol. 

Now one brother will not be left unarmed in a water fight, and will use all his ingenuity to overcome the lack of a second water piston. And there never was nor will be a water fight that did not escalate beyond all reason.

The water pistol had not been put to very much use before the soap dish was involved as both a carrier and dispenser of water.  As an efficiency improvement in the art war it is only a minor footnote, and interesting only in relation to the subsequent escalation of which it was the direct cause: the inflatable beach ball.

Your imagination is only faulty in one respect. The inflatable beach ball was not entirely inflated with water.

The inflatable beach ball is a dispenser of water to exceed all in those days before the pump-action super-soaker, but one could suffer a lot of hits in the time it takes to fill. To be well used it doesn't need to hold that much more than the water pistol. And if not fully filled it may also serve as a sort of bowl to hold more water.

This was peak escalation - and there were two beach balls.

From the child's point of view, we were having unpermitted quantities of fun, but the parent would think: "What are they doing up there? They are supposed to be going to sleep!"

Despite all these details being true, I'm not aware that any of the bedding actually got wet.

Our mother, on the other hand, observed that it all needed hanging out on the washing line to dry, and as there was no other bedding to hand we would have to go and play outside in our pyjamas and bare feet! 

See how we like that!

We liked that. 

We rode around the "lawn" on our tricycles in our pyjamas and bare feet, our fun a form of defiance at our supposed punishment.

What to do when your lemons are returned to you, frozen? 
If it's summer, make lovely chilled lemonade.