Gerard Ruiter was standing on a stepladder when Max came in on Saturday morning, sorting a drawer of resistors with his glasses pushed up on his forehead.
He looked down over his shoulder.
“Ah,” he said.
“The son.”
Max stopped by the counter.
The bell over the door was still jangling.
“Your father was in,” Ruiter said.
He came down the ladder one step at a time, holding the rails with both hands.
He was seventy and moved like it, carefully, but his hands on the counter were steady as a surgeon’s.
“Thursday.
Big man, orange jacket, didn’t take it off.
Stood where you’re standing for twenty minutes and bought screwdrivers.
Asked me what a boy would need next if he’d bought a Z80 and six counters and a crystal off me.” He peered at Max over the top of the counter.
“I told him an EPROM.
And something to erase it with.
He wrote it down on his receipt.
Did you get it?”
“I got it.”
“Good.” Ruiter folded his arms.
“He didn’t buy them, though.”
“No.”
“He said, the boy’ll want to buy them himself.” Ruiter shrugged.
“I thought that was a strange thing to say.
Then I thought it was the least strange thing anyone’s said to me in this shop in about a year.” He leaned on the counter.
“Well?
What’s it to be?”
* * *
Max had made a list on Friday night, in the schrift (exercise book), on the page after the box.
Otto had checked it twice and then a third time, because the money was very tight and Otto didn’t like being wrong about money.
Two 2764 EPROMs, eight kilobytes each, with the little quartz window on top: fl 8,75 each.
An LM317, a voltage regulator, to make the twenty-one volts the EPROMs needed to be programmed: fl 2,40.
Two 74LS373 latches, to hold the address while the MSX sent the next byte: fl 1,60 each.
A twenty-eight pin socket, a handful of transistors and resistors, a strip of veroboard: fl 4,90.
A transformer.
He didn’t have money for a new transformer.
“Hm,” said Ruiter.
He went into the back and came out with a cardboard box full of transformers, dusty, tangled, with their wires knotted together.
He picked one out, looked at the label, and put it on the counter.
“Twenty-four volts.
Out of a tumble dryer, I think.
Free.
Nobody wants them.”
“Thank you.”
“And for erasing?”
Max hesitated.
A proper EPROM eraser was a box with an ultraviolet tube and a timer.
New, from the catalogue, it was about a hundred and twenty guilders.
Otto had said so, quietly, the night before, and they’d both left it at that.
“I’ll leave them in the sun,” Max said.
Ruiter laughed, a short dry bark.
“In Arnhem?
In September?
You’ll be waiting till Easter.” He went into the back again, and this time he was gone for a while.
Max heard boxes being moved, and something fall over, and the old man swear softly in Dutch that was mostly about the drawer and partly about God.
He came back with a grey metal box the size of a shoebox, with a switch on the side and a little slide-out tray at the front.
“I built this in 1984,” Ruiter said, “for a man who was going to make me rich with a computer for the bakery trade.
He went to Australia.
Never paid me.
The tube still works.” He tapped the lid.
“Don’t look at the light.
It’ll cook your eyes.
Fifteen minutes erases a 2764, twenty to be sure.”
“How much?”
Ruiter thought about it.
Max watched him think about it, and saw him decide.
“What it cost me,” Ruiter said.
“Twelve fifty.
Because nobody else ever asks for them.
I’ve had it on the shelf six years, and every year I say I’ll throw it away.”
“Thirty-eight forty,” Otto said, as the old man rang it all up on the till, “out of forty-two forty.
Leaving four guilders.”
Four guilders.
“For three weeks.”
Four guilders, Max thought, and an eraser and two EPROMs and a regulator, and everything a computer needs to start, in a paper bag.
On the way out Ruiter called after him.
“If you blow it up,” he said, “come back and tell me how.”
“You said that last time.”
“I mean it more now,” said Ruiter, and went back up his ladder.
* * *
He built the heart first.
The Z80 sat on the breadboard, forty pins, black, with a small notch at one end.
It was the same chip that was in the MSX in his bedroom.
It was the same chip that was in a hundred arcade machines in Japan.
It cost fl 6,50, and it did nothing at all until you gave it a clock.
The crystal he’d bought by mistake, the American one, ran at 14.318 megahertz.
Divide that by four with one of the counters and you got 3.58.
That was exactly the speed the Z80 in the MSX ran at.
“Which isn’t a coincidence,” Otto said.
“The MSX people bought the same wrong crystal on purpose.”
The clock was easy.
Reset was a resistor, a capacitor and a push button from an old doorbell.
Then the test that every person who had ever built a computer from parts had done, for thirty years, in sheds and bedrooms and university labs: tie every data line to zero.
To a Z80, zero meant NOP.
No operation.
Do nothing, and move on to the next address.
So with nothing but zeros on the data bus, the Z80 would wake up, read address 0, find nothing to do, go to address 1, find nothing, go to address 2, and keep going, forever, counting through all sixty-five thousand addresses as fast as it could, then wrap round and start again.
Each of the sixteen address lines would flicker on and off, each one half as fast as the one before.
The top line, A15, would go on and off about twenty-seven times a second.
Too fast to see.
So he put a counter on it, to slow it down, and an LED from the bag on the output of the counter, with a resistor.
He pushed the battery clip on.
The LED blinked.
Once a second, steady, like a heartbeat.
Max sat back on the crate.
He realised he’d been holding his breath.
“Node 2a,” Otto said, and somewhere in the corner of his eye the tree chimed one note, soft.
“It’s alive.
It’s doing nothing, extremely quickly.
Which is all any computer does when you haven’t told it anything.”
Sanne came out to look on Sunday.
It was the first time she’d come out since Pap left.
She stood in the doorway in her coat, because it was raining, and looked at the breadboard and the blinking LED.
“What’s it doing?”
“Thinking.”
“About what?”
“Nothing yet.
It’s waiting for me to tell it.”
She watched it blink.
“It’s like a heart.”
“It’s a bit like a heart.”
“Is it Puntje’s heart?”
Max thought about it.
“Yeah,” he said.
“It’s Puntje’s heart.”
Sanne nodded, satisfied, and went back inside.
But she left the shed door open, so he could hear the TV.
* * *
The programmer took four evenings.
It was a strip of veroboard with the socket in the middle, the two latches on one side and the regulator on the other, screwed to a cooling tab cut from a biscuit tin lid.
The MSX was the host.
It had a printer port on the back, eight data lines and a strobe, and nobody in this house had ever owned a printer.
He soldered a cable from an old Centronics plug that Ruiter had thrown in for free.
Then he sat at his desk on Tuesday night, after training, with his legs shaking and a tea towel of ice on his blistered finger, and typed a BASIC program into the MSX by the light of the desk lamp.
It took him two hours.
It was eighty lines long.
It sent an address, low byte then high byte, to the latches, then sent a data byte, then switched on the twenty-one volts for fifty milliseconds.
That was how long a 2764 needed per byte to make the charge stick.
Then it read the byte back, to check.
Then it went on to the next address.
At fifty milliseconds a byte, eight kilobytes took about seven minutes.
“Save it,” Otto said.
I’m saving it.
“Not on that one.”
Max stopped with his hand above the cassette deck.
In it was the C60 with HUISHOUDBOEKJE (household book) written on the label in his own fourteen-year-old capitals.
Every guilder the family had spent since 1988.
He took it out very carefully and put it in the drawer.
He put in a blank C60 he’d found in Henk’s room, still in its wrapper, and wrote PROGRAMMER V1 on the label in biro.
“Thank you,” said Otto.
“I’d have had to haunt you.” This story is hosted at novelping.com.
* * *
On Wednesday he burned his first EPROM.
The program was sixteen bytes long.
He’d written it in the schrift in pencil, in Z80 machine code, because he didn’t have an assembler.
He’d looked up each instruction’s number in the MSX manual’s appendix, which had a table of them in tiny type.
Load a number.
Write it to the latch that held the box’s position.
Add one.
Wait.
Jump back to the start.
He typed the sixteen bytes into the MSX one by one as DATA statements.
He put the EPROM in the socket and pressed RUN.
The MSX sent byte 0.
The regulator got warm.
Byte 1.
Byte 2.
It took less than a second.
The screen said:
16 BYTES OK
He pulled the EPROM out and put it on the breadboard where the zeros had been, and took the zeros away, and wired the Z80’s write signal to a latch, and the latch to the box’s comparators, in place of the wires.
He pushed the battery clip on.
The box on the screen of the Bakker TV moved.
Not when he moved a wire.
On its own.
It slid from left to right, slowly, smoothly, one dot per frame, across the screen, until it ran off the edge and came back on the left and started again.
Max watched it go across six times.
“You’ve built a computer,” Otto said.
“It’s bad, it’s tiny, it’s on a breadboard in a shed.
It has no memory, it’s got sixteen bytes of program, and it can do one thing.
But it’s a computer.”
It’s not one yet.
It can’t remember anything.
“Then give it something to remember with.”
* * *
He did that on Saturday.
The 6116 was the RAM he’d bought in August, two kilobytes, the size of a fingernail.
Twenty-four pins.
He’d been saving it.
It would be the screen memory, the tile map, every wall of the maze in a grid of squares, which the picture circuit would read fifty times a second and the Z80 would write to whenever it wanted something to change.
It was late.
He’d trained Thursday, he’d done the run on Saturday morning, he’d done the shopping and the bath and Sanne’s spelling words.
Otto was getting slow again, grainy, half a second behind.
He found pin 1.
He pushed the chip into the breadboard, checked it, checked the wires, and pushed the battery clip on.
The LED blinked.
The box didn’t move.
Then there was a smell.
It was sharp and sweet, like a hot hairdryer, and it was coming from the middle of the breadboard.
Max put his finger on the 6116.
It was hot.
Not warm.
Hot, like the side of a pan.
He ripped the battery clip off.
He pulled the chip out with the new small screwdriver, and turned it over in his fingers.
The tiny dimple that marked pin 1 was at the wrong end.
He’d put it in backwards.
“I…
should have caught that,” Otto said slowly.
“I’m sorry.
I’m…
very tired.
You’re very tired.”
Is it dead?
“Very likely.
Twenty-four pins, backwards, with power on the wrong side.” A pause.
“Yes.”
Max sat on the crate in the cold shed with the dead chip in his palm.
It was about the size of a stick of chewing gum and it had cost fl 9,25 in August.
“You have four guilders,” Otto said, very gently.
Max closed his hand round the chip.
Then I’ll need more than four guilders.
Every chapter goes free here in time.
~ F0rk