CakeEngine (u/CakeEngine)

CakeEngine commented on In the 1980s we downloaded games from the radio newslttrs.com/yes-in-the-... · Posted by u/spzb

CakeEngine · a year ago

Also in the 80s we (by which I mean other people), downloaded software from the television by sticking an LDR to the screen whilst a dot flashed black and white during the duration of a programme. A program from a programme.

I remember see the dot a few times, but it was probably very short lived.

CakeEngine commented on Low Cost Robot Arm github.com/AlexanderKoch-... · Posted by u/pbrowne011

RecycledEle · 2 years ago

There is a reason there is no standard hobbyist-grade robotic arm.

People think they can build their own robotic arms for leas than a "real" robotic arm costs, but the do not account for wobble or repeatability.

With all due respect to the person who posted a design for a robotic arm made with RC servos on HN, I would like measurements of the repeatability. Have it draw the same pattern on a piece of paper every day for a week. Show me how closely the 7 lines overlap. I doubt that it can draw such a thing; it will tear the paper or get jammed without the strength to tear the paper.

Source: I've been building hobbyist robots since the 1980's, researched robots in the 1990's including a masters thesis, and teaching robotics for most of the last decade.

CakeEngine · 2 years ago

Is this not something that can be addressed with cameras and (maybe) learnt approaches now? You don't need blind repeatability if you've got good visual monitoring to close the control loop, you just (just!) need good accuracy and low latency from video to motor control.

CakeEngine commented on The history of Digital Research's Gemdos for the Atari ST (1986) cd.textfiles.com/crawlycr... · Posted by u/lproven

unwind · 2 years ago

Interesting that this uses the coding convention of putting parentheses around the expression in return statements.

So

    return (1);

instead of just

    return 1;

I remember using the former style as I tried (in frustration) to learn C back on the Amiga (so roughly at the same time, late 80s/early 90s) using articles in magazines.

Does anyone know where it comes from?

Some time later (late 90s) at university I learned C again but with actual (good!) teachers, and also got exposed to way more code and talk about code thanks to Internet and comp.lang.c etc, and around that time (I think?) I stopped using them.

Nowadays they always make me think the author is anxious that the function will return before the entire expression is evaluated, which makes me smile. :)

CakeEngine · 2 years ago

Another early 90s C learner here, and I also put (and still do!) parentheses around return expressions. But I do:

   `return( 1 );`

not

   `return (1);`

...because the bracket belongs to the return, not the expression. It's by analogy with 'if' and 'while', a mental "look out, here comes an expression" warming.

CakeEngine commented on Simulating protected mode in the Z80 [video] youtube.com/watch?v=DLSUA... · Posted by u/tux1968

ddevault · 3 years ago

Correction: you can do pre-emptive multi-tasking on z80. I wrote an OS to take advantage of this back in the day. It has interrupts, after all. User programs (as it were) can disable interrupts, but the z80 has NMIs as well if your hardware configuration is suitable for it.

CakeEngine · 3 years ago

Indeed. There's also UZI - a v7 UNIX for Z80.

CakeEngine commented on Simulating protected mode in the Z80 [video] youtube.com/watch?v=DLSUA... · Posted by u/tux1968

rep_lodsb · 3 years ago

>The vid even shows what set of instructions this 'mode' would break.

It would be possible to add more hardware to detect these instructions, so it could then trap and emulate them.

CakeEngine · 3 years ago

I don't think it would be. You'd have to detect them on the data bus and also differentiate between data and instruction accesses which I don't /think/ the Z80 does, at least not easily.

CakeEngine commented on Ask HN: What's the next big thing that few people are talking about? · Posted by u/ScottStevenson

ChadNauseam · 4 years ago

Preimplantation polygenetic testing. The idea is that, when doing IVF, you sequence the genome of all the embryos and implant the ones that you predict will have properties that you like.

This already exists for monogenetic screening (for parents who don't want to pass on heritable diseases for their children, where those diseases are localized to one gene). But the idea here is that, by checking thousands of genes, you can make predictions for things that start to be very relevant to parents, like attractiveness or height or intelligence.

I don't think people understand how important this is going to be. If the process is expensive, it will only be available to rich people. In a generation, maybe they'll have children that are more intelligent or more attractive than average.

If that starts happening, I think it would have pretty negative effects on society, but there's no way to really prevent it (rich people will just go to Singapore if you ban it in the US). So the only reasonable option is to have the government subsidize it and make it affordable to everyone.

CakeEngine · 4 years ago

This is only a problem is there's a clear mapping from detectable genetic feature to an expressed macro-feature like intelligence.

My (admittedly limited) understanding is that each detectable genetic feature has a whole panoply of effects, some of which wont' be apparent at birth. Selecting for intelligence through specific genes is like to also be selecting for weak bones, reduced longevity, or other unpredictable side-effects.

Maybe one day it will be possible but there's a chasm between here and there which can only be crossed by extensive testing on real people. Is that even crossable?

CakeEngine commented on While I’m on a tech rant – who invented this piece of pure sadism? twitter.com/hackedoffhugh... · Posted by u/HL33tibCe7

CakeEngine · 4 years ago

Folk are getting hung up on the keyboard layout and poor buttons, which are bad but only the start of the problems with these machines.

It has two separate asynchronous screens, two sets of printed instructions (plus t&cs), more instructions on both screens, then two keypads (but with the same symbols although they're not interoperable). There is no consistent self-explanatory language for talking about the various buttons, knobs, slots and problems, and how the user's attention should flow between them. If use of this machine wasn't mandated, nobody would ever, ever touch it.