56. Parallel Processing

Nigel tried to sleep, which didn’t work.

The only thing to do, that Nigel could think of, anyway, was to ignore the wormhole and the field and any messages on arrows for now. He couldn’t get there and back in the little time he had off to check. Maybe he could go in his eight hours allotted for sleep, the ones he was supposed to be using now, but even that was cutting it very fine.

It would have to wait. Even if he caved and told the other three who knew, they also couldn’t drop everything to chase possible time machines that were of no use to them and might even present a problem. This one was hardly Wells-style, one that faithfully tossed you out wherever and whenever you wanted to go, like a train. At least that meant it probably couldn’t be weaponized into a causality-wrecking free-for-all. He dropped back into uneasy sleep.

***

“How’re your parents these days?” Mateo asked. He was delicately seating a valve in place on the growing behemoth.

“What? Fine, fine, they’re fine.”

Mateo was too engrossed in his work, even twelve hours in, to turn and give him a funny look. But he radiated skepticism even from this angle. Right. He wasn’t a fool. And Nigel had been acting a little strange with him since returning from finding the arrow. Of course he assumed it was some family difficulty, and was trying to tactfully express concern if Nigel wanted to respond.

Nigel sighed. “They really are fine. I’m just worried about this project.”

“Join the freaking club, man. How’s Heath?”

“He’s coming along.” Nigel had accidentally picked up his habit of talking about the Heath Robinson like it was some crotchety gentleman.

“Good, good.” It probably didn’t hurt his already considerable investment in Heath’s construction that Nia was assigned to it. “And oh, if you get ash on this vacuum tube I swear I will end you.”

Nigel stepped back ostentatiously. “I doubt that would stop it working.”

“Don’t care, I love this bank of tubes like my own kids.”

Oh God, no, he couldn’t —

“You have children?” He must have sounded as horrified as he felt, because Mateo actually stopped to look at him.

“No, dude. If I did, I’m sure I would’ve told your weird friend at some point.”

“He’s not exactly my friend,” Nigel said, to cover his relief. If he’d had children, abandoned in the future...

“Whatever. No, I didn’t ditch any kids.”

“Ahaha, that’s good.”

“It sure is, man, it sure is.”

***

Block H was always warm, now that they were starting to turn the vacuum tubes on and — like Flowers said — leave them on. They drew a crazy amount of power, were way too hot to touch, and made the whole block room really cozy on a November midnight when it was freezing rain outside. They hummed, and the whole room had a weird but kind of familiar smell, like right before rain or the back innards of an old TV.

It seemed even more alive now, like it was keeping an eye on its own construction. Even though it was only about ten months old and not done yet, it felt like some wise old ancestor. In a way, Mateo guessed it was. The grandfather of every computer he’d ever used, with Turing’s Bombes the great-grandfathers. He felt honored to touch it.

“I just want to see it in action,” Nigel said one night as they and the others were getting ready to clock out. “Proof in the pudding and all that.”

“Huh?”

“Er, old expression. Proof of the pudding is in the eating.”

“Then heck yeah. I want dessert.”

Nigel grinned, like he couldn’t stop looking at it long enough to go sleep.

“You got it bad, man,” Mateo added.

“So do you!”

Mateo had burned the back of his hand by brushing it against a vacuum tube that’d been on for like eight months, and it was just now healing up. It left a purplish scar. He didn’t mind. It seemed like a badge of honor, like getting gang tattoos, but without all the crime and stuff.

“I ... I think we might be on track to get it done,” Mateo said, opening the door, going out into the freezing rain to get dinner and sleep. “Man, these hours. It’s so worth it if this works, though.”

“I’m going to sleep the clock round. I hate night shifts.”

“I’ll settle for eight hours now right now. I’m bushed. Testing in two days if nothing blows up.” He put his hat on. He remembered pretty consistently these days, especially in weather like this. The brim kept the ice water from going down the back of his neck.

Nigel splashed out next to him, heading for Hut 2 and then their dorm. Mateo was almost tired enough to skip Hut 2 but he was starving by now too.

“Don’t jinx it.”

“Right.”

***

Everyone who’d been assembling the new machine was there on that day in December to see the test. Nothing could’ve kept Mateo away, and he would swear Nigel’s pupils were a size bigger just looking at the thing. Block H was packed with every post office shift there at once, and between all the people and all the vacuum tubes, the place was seriously warm. Mateo was down to his shirt, no sweater. The Brits, not used to real heating in a building or real summers, were feeling it.

Mateo liked it. Winters should be freezing cold and snowy outside and warm inside, not sort of damp and chilly on both sides of the door.

But whatever. Who cared. They were going to finally see the Ancestor in action.

The vacuum tubes were already humming because they were on 24/7. The room really smelled like hot ozone. Stuff clicked, fast and regularly, down in the mechanical stuff they still had.

Mateo trusted all of that. They were still stuck with one roll of paper tape on the Heath-style ‘bedstead.’ Mateo didn’t trust it. Flowers had apparently tried to totally eliminate it from his design but they couldn’t really do it. You could code all the code wheel possible starting positions in wires and plugs and vacuum tubes and then leave it the heck alone and not jostle it, and then program it as you needed by shuffling wires around back there, but even if the jerks had the same code machines you still intercepted different messages every time. And you had to put that sucker in binary real fast and have it ready to run. So tape it was for the messages. Mateo gave it the stinkeye.

A couple of the Wrens loaded the test tape, feeding it around that maze of pulleys and wheels. They were almost like Nigel had been with his Mp3 player, like this was their territory. Nobody argued. They knew their stuff and nobody messed with it. Even the designers couldn’t load the tape. Flowers, who was a real tinkerer, had tried once, then bowed out really politely to the experts, who rolled up and loaded his tape through his own design for him.

Somebody flipped it on. Nigel made a quiet noise. The tape started to whirr around, low speed, easy, no problems. They amped it up a little. Still no problems. The tape hardly looked like it was moving, all steady and the punched holes all blurred out.

“9000 characters per second,” said one of the Wrens when they amped it up again. Mateo sucked in a breath like was about to pass out. Heath maxed out at 2000 characters/sec.

“9500 per second,” she said. “9600. 97—“

The tape exploded. It happened too fast to really tell what happened, but when they’d finally found all the pieces and made Mateo climb up and balance on a stool to get the last one out of a fluorescent light clear over on the far side of Block H, they could piece it together. What happened, anyway, not the tape. The tape was a writeoff.

“What was our top speed?” Flowers wanted to know.

“9700 characters per second,” said Edith. “Or sixty miles per hour, if you like. I wouldn’t recommend much over 5000 characters per second unless we’re willing to deal with constant tear-outs like that.”

Flowers looked bummed and encouraged at the same time. “Thank you.”

***

“We’ll have to build another one of these, then, at least,” Nigel said quietly to Mateo. It was the next day in Block H. The giant computer hummed quietly as they checked tubes and solder and wiring.

Nigel would only talk about weird time travel stuff in the middle of an open field, but he’d chill out enough to talk about this computer while they were in Block H. Edith was sighting along a couple of tape pulleys down at the other end and ignoring them. Work was going on around them.

“How come?”

Nigel sighed like a tire leaking.

“It’s not fast enough.”

“It’s more than twice as fast as Heath,” Mateo argued. “We all knew the tape was gonna blow out at some point, that’s why they were testing.”

Nigel shook his head. “We need faster. They’re not going to wait politely for us to decode messages before they send the next one. And we don’t have time to build more and more of these things.” He looked wiped.

“Come on, dude, we’ve got a bunch of genius engineers and math nerds around. This place is gee—boffin central. You can’t throw a rock here without hitting a genius. The Wrens can all think me under the table. You guys’ll come up with something.”

“Likely,” Nigel admitted, and glanced at him for a second. Like he was wondering if that was a Spooky Message From the Future or just being optimistic. Mateo shook his head at him, just a little. Sorry, man, I don’t know. Nigel looked back at his job.

Mateo spent part of his off day on a hike. Two hours out, two hours back. He needed a haircut, by back now standards, but he wanted to be outside even more. He wanted space to think, like he was too close to the Mother of All Computers to really see it.

What else was it missing? It’d been so long, by his own internal timeframe, since he and Avi had put that paragraph about Flowers on their science fair project poster. That’d been, what, eight years ago by his own timeline? He couldn’t tell Turing anything because Turing already knew.

Mateo only knew what a computer was, back in the future, because Turing had basically defined them. Now they had engineering problems, and engineering problems were Flowers’ wheelhouse. It was like Turing was the soul and Flowers was the body. But the upshot was that finding some hardware thing that he knew about from the future was their best bet. The theory between Turing’s Bombes and his PC was a pretty straight line. The hardware wasn’t. The trick was making the hardware good enough to hold the software.

What was the difference? What did, say, his PC, or even his Mp3 player have that the Ancestor didn’t? Aside from freaking chips. He got distracted finding a gap in the hedge crossing the field. More rain was blowing in. He’d have to watch it, January rain sounded like a killer even here.

Uh...well, you COULD program it, like, you could change the simulated starting positions of the enemy code machine wheels — like, wow, did that make this the first computer simulation? — by going down into the guts of it and changing the wiring. That was the only way you could save a program, though. Once you changed where the wires were plugged in, it was gone. So...no way to save programming aside from hardwiring. Did the hardwiring count as memory? He didn’t know. He didn’t think so. You couldn’t save multiple programs and pick one to run. What if you could run multiple programs at once? Like, program a bunch of different hypothetical starting wheel positions and run them all in parallel against each character as it came in on that evil paper message tape?

Yeah right, run multiple simulations at once on a bank of vacuum tubes and wires like a phone switchboard from an old cartoon. While I’m wishing, I want a million dollars and a pony. Yeah right. It’d have to be even bigger and weirder and it was basically maxed out on big and weird now.

The rain started coming in. It wasn’t bucketing, but it was steady. At least these big wool coats shed water better than he’d thought. He should keep walking, though. Maybe go ahead and head back. He’d been walking for maybe an hour forty. Future boots splashed through mud from now. At least he didn’t have to worry about software and hardware compatibility when it came to them.

He got back with thirty minutes to go before he needed to go to work. Hut 2 and hot tea it was, then. He got it pretty fast — not peak hours — but then he wandered out, sipping his boiling tea and not really caring if the rain got in it. He walked towards Block H like he couldn’t stay away.

The post office nerds were in there working on it, running tests, fooling around with programs. Seeing them being wizzes calmed him down some. It was warm in there, and his fingers started thawing out. He took off his hat so he wouldn’t come off like a jerk and found a stool way back in a corner so he couldn’t spill tea on the computer. Nobody else called it that, not even Flowers. They had the word but they didn’t call it that.

Flowers came in. Mateo didn’t say anything since he went straight over to the machine and seemed like he was on a mission, but he was glad to see him. Meeting Turing was like meeting your patron saint with a glowy halo and just about as comfortable, not Turing’s fault but just how things were, but he and Flowers had actually hit it off some.

He’d also grown up in a blue-collar family and gone to a trade school, and spent a lot of time when he was a kid tinkering around and building stuff. They kinda split off there, though. Flowers worked for the post office on their new automated phone system, which sounded dorky and old-fashioned until you realized that was the bleeding edge of technology back now. If he was in the future he’d be designing those smartphones Apple was supposedly coming out with. And oh yeah, he was a super genius, another way he was different than Mateo. He was just such a chill humble guy he let you forget it.

Mateo finished up his tea and remembered to hide the cup by wedging it into a rafter this time. He took off his coat and rolled up his sleeves and went to the nearest nerd to report for duty.

Flowers was down between the two banks of vacuum tubes, doing something with the wires and taking notes. Mateo focused on his own hardware job, taking over for Edith’s soldering when she clocked out. Better than all that Boolean Logic stuff the geeks had to deal with. He didn't really know what Boolean Logic was except it was terrible and made no sense and was apparently important for computers.

As he went to get more solder from the rack in the corner, he tried to remember (for the zillionth time) what those couple of paragraphs in that library book he’d used for the science fair had said about Flowers.

Right now he was still plugging away at whatever he was doing between the computer banks. Guy worked hours that Tineye would just barely keep up with and seemed happy to do it. Nerds. Come to think of it, he and Tineye were both kind of crazy wartime white hat hackers, even if he kinda hated to admit Tineye was white hat.

One of them just went in for people and the other one went in for computers. And FINE, they were about equally unlikely to punch you, as crazy as that idea was.

He checked his soldering iron before going back over to the vacuum tube switchboard thing. Ok, all that was true, but it wasn’t any help. What did Flowers invent that he could give him the idea for a little sooner?

“It’s a shame we can’t process any of the information coming off the message tape any faster,” Flowers said conversationally through the bank of tubes.

“Sir?” Mateo said, not sure if he was talking to him or one of the engineers. Nigel had set him, Mateo, up as some computer wiz, and Flowers sure was happy to learn from experts from around the world. He’d actually been at some kind of proto-computer nerd convention in Germany the day war was declared.

“We could shave off quite a bit of time.”

“Yeah, true.” So he was talking to him, for all the good that’d do him. “It’s too bad we can’t run more than one starting position at once, sir.”

“Well, if this goes well and doesn’t give us inconsistent results like the Heath Robinson, we might have another one commissioned to speed things along.”

“I don’t see why nobody cares about this thing,” Mateo said. “It’s freaking magic.” Word was the Flowers had put his own money into it. The Station X bosses really hadn’t bitten. It was tempting to run around like ‘Oooh, I bring a message from the fuuuuuuture!’ but A. that would be dumb and B. he didn’t have one.

Flowers shrugged. “We’ll see how it goes.” He didn’t seem to worry much about stuff outside of his control.

Mateo nodded, and got distracted. What if there’s a way to run more than one starting position at the same time on just this one? What if there’s some kind of computer memory you can hack together with vacuum tubes? Doesn’t have to be a lot, just enough have some kind of info that’s more code than hardwiring...

“Computer memory? Parallel processing I think I follow.”

Aw snap, he must have said some of that out loud.

“Uh, yeah, sir. That’s what we call it back home.”

Flowers looked at him between the vacuum tubes.

“Tell me about it.”

Mateo’s heart was suddenly racing, and he wasn’t sure if he was excited or just freaked. “Well, uh, it’s a way to hold more than one program, like uh, one algorithm at a time. I guess...” He hesitated. “I’m sorry, I’m probably going to get all the words wrong.”

“That’s all right, go on.”

“It won’t help with the input speed, but if you could chain, uh, I dunno, two of your processors together in parallel it would be like running the message tape twice in the time it takes to run it once.”

Flowers came out from around the bank of tubes. He had this light in his eyes. He got it. He got it like any future person, but just from his own head. Crazy.

“Go on?”

It clicked that he must think Mateo was about on his level, since he could explain stuff to Mateo about computing and Mateo mostly just got it, at least in broad strokes. Nah man, sorry, I’m just a regular dope who plays with computers from the future.

“Well, uh...if you stored your program in two, uh...you call them processors, right?”

“I know what you mean, sure.”

“Then you could ... uh, I guess the problem is getting the signal from the tape reader to the processors. You’d have to time it somehow...”

“A clock pulse could do that. Just a low voltage at regular intervals.”

Oh good, thanks man, you know what I’m talking about. More than I do. Shut up and listen, he’s saying something—

“You could time it with the tape reader, and that would take some strain off the tape reader, too. How would you keep the algorithm stored in the processors, though? It’d have to change over time as the tapes went through. Really quite fast, too.”

“How hard is it to flip a bi— a unit?” Mateo said. He felt like he was shoving his way through undergrowth while Flowers was jogging down a sidewalk. He was getting a headache.

“Easy, if you use valves rather than relays.” Flowers looked at him. “The clock pulse could do it, for one.”

“How fast? I mean, how long would it take?”

“A fraction of a millisecond, easily.”

“Uh. Hm. Ok.”

There was something there. Mateo didn’t have to figure it out. He just had to remember and show the way and Flowers would figure it out.

“What if you...you stored a different starting position for the wheels in each of the two processors, right? Like you have now but two in parallel instead. And get the bits — the units, sorry — coded all right and ready to go in both of them. Storing it, right? Like a, a memory in the units’ pattern, not like ... hardwired in the valves. And this clock pulse, could it ...?”

“Flip the units across the board in the processors as the tape passed? I suppose it could. Huh!” He made a quick note.

***

Nigel came in to see Flowers and Mateo hunched over a tall wooden stool with a notebook on it. They were passing a pencil back and forth.

“—but like, so, if you move a number to the left one spot, that’s, uh...”

“Multiplying it by two, yes.”

“Yeah, yeah! My point is you can basically use these —uh, what do you call ‘em?”

“Shift registers.”

“Shift registers! You can use them like the cache, uh, call it temporary memory, since they’ll just sit there in your sequence of binary units until —“

“—until we send the clock pulse through —“

“— and then you can wait and do math to them whenever you want!”

“That solves the whole problem of the electric eye having trouble keeping up too! Is there any reason we could only use two of the parallel processors? I can’t think of one. I’d like five.”

“...uh...wow. Huh. If you can make it work the theory is fine. I guess you’d need to make the serial-in parallel-out signal work for more than two, but ...” He shrugged. “It, uh, it’s been ... the theory is fine. You could have a zillion processors running in parallel, I guess.”

“I think we can find a way. You sound like me in my early days at the post office, except not nearly so bad as I was. I knew all the theory and none of the engineering!”

Mateo grinned. “I can’t imagine that, sir.”

“Well, we need to put these ideas in the works to test. I think you’ve got something here.”

“Heh, uh, it’s not me. I’m just telling you what smarter people told me.”

Nigel tiptoed over to his station.

***

They’d started calling it Colossus. The feeling of another bizarre little prophecy coming true was hardly even a feeling in the normal sense. It was more like shocking yourself thoroughly on a wire that turned out to be live after all. And Mateo’s suggestions, bizarre future things, were already being built into their second overhaul of the machine.

It was still being mostly ignored. Nigel half-wanted to scream. You have a man from the future! Put him to good use!

He had to admit he’d doubted himself if Mateo would be able to produce anything useful to them, but now he had with a vengeance, dumping future concept after future concept into Flowers’ arms. Flowers thought he was the best thing to happen to valve calculating since wire, somebody who actually could see what he was trying to do and how vital it was that this machine in particular would come into use.

Mateo didn’t have the present engineering knowledge to design or build it, but few people did. His combination of ethereal future theory and a workingman’s skill with tools made him slide, almost inevitably, into the role of an unofficial assistant to Flowers and his team.

They were indeed building the parallel processors, five of them, to simulate the five mechanical synchronized wheels of the twelve that made Tuny’s code. They had what Mateo called memory, too.

Instead of the valves Mateo had suggested for that application, Flowers tested those and found them, if not the basic idea, wanting. Instead he used thyratron valves, neon-filled things arranged in rings, that glowed softly like the embers of a dying — or a banked — fire in among the racks of Colossus.

He found Mateo preparing to go get dinner one evening, but apparently unwilling to tear his gaze away.

“Look at that,” he whispered in tones of awe when Nigel came over to him. “We had a test run work this afternoon. We got up to 25,000 characters per second and that’s with a safety margin of two. That’s sick.”

Mateo generally tried to keep his future slang in check, but he made an exception for Nigel. Either a mark of friendship, or allowing himself to unbend around someone who knew his origins.

Nigel had to think. “Sick” in Mateo’s dialect could mean “unwell” or “perversely cruel”, like in his own, but it could also mean a feat, a work of craftsman's skill so extreme it took on a kind of beauty.

He nodded. “It certainly is.”