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Annoying Robot

11:45

Q: Using a modern microcontroller to explore early home computing concepts

I'm working on a project to write a small OS based loosely on the functionality of CP/M. I want to better understand a few things about the early home computing market, as well as to understand operating systems concepts. I'm using a Cortex M0+, which has, among other things, 8K of RAM. From t...

operating-system

3 hours later…

Annoying Robot

14:17

Q: Why does the cassette sound muffuled?

I tried loading a cassette into a cassette player, I've clean the heads of the cassette but it sounded like a person gurgling water.

cassette-tape

5 hours later…

wizzwizz4

19:21

@JAL Did you publicise my randomness question?

You're the main person who does that, as far as I can see, and there was a large influx of answerers ~2h ago.

Chenmunka

The power of HNQ

wizzwizz4

@Chenmunka When it first became HNQ, it wasn't noticed much at all.

Time zones?

Chenmunka

Time zones always help.

JAL

19:37

I wish, the traffic is probably from HNQ

It might be a good candidate for the /r/programming subreddit

I'll post it to see if we can get any other technical answers

wizzwizz4

@JAL No! You'll get all of the gold badges!

JAL

wizzwizz4

They'll be none left by the time you're finished with them.

JAL

Still trying to be the first person to get a bronze badge

wizzwizz4

@JAL Get a bronze badge for what?

JAL

19:40

I need to think of some more nintendo q&a pairs

nintendo tag

wizzwizz4

@JAL Oh. That one.

I tried, but... -.(o.o).-

Chenmunka

Back in the '80s I wrote a random number algorithm for the HP9845 because the RAND() function was rubbish. Can't remember what I did though.

JAL

@Chenmunka that would be awesome if you could dig it up

@wizzwizz4 yeah, they can be hit and miss sometimes

wizzwizz4

@Chenmunka Was it used in a production system?

Chenmunka

It was for Monte Carlo simulation of an optical fibre production lathe. Testing how far out of tolerance you could go before the light wouldn't go down the fibre well enough to be useful.

I remember finding an algorithm on the internet (using Gopher in those days) and hacking it into HP-Basic.

wizzwizz4

19:43

@Chenmunka Was it on the WWW?

If so, it might be in web.archive.org

Chenmunka

Not in the 1980s it wasn't. The web didn't come in until 1993.

wizzwizz4

@Chenmunka So, Usenet?

Ooh! I've been emailed something... That's interesting.

Chenmunka

No, I'm sure I Gophered it off some FTP server in a US university.

wizzwizz4

... Of course FTP predated HTTP! What was I thinking? *slaps forehead*

Chenmunka

Gopher was the search protocol. Once it had found something, then you FTPd it to your machine.

wizzwizz4

19:46

@Chenmunka Oh... I thought it was a web browser (but for <insert protocol name here>).

Chenmunka

No, again - predates the web, no browsers. Text mode only.

JAL

@wizzwizz4 my reddit submission just now, for reference: reddit.com/r/programming/comments/5sgddx/…

Chenmunka

It would "Go for" the files you wanted

JAL

ahhh that's so clever

wizzwizz4

@Chenmunka Oh, yeah. Obviously text; graphics are overrated.

Chenmunka

19:50

Any way, the algorithm had something to do with creating a 64-bit integer and shifting, multiplying by the number you first thought of. That sort of thing.

wizzwizz4

@Chenmunka I suppose if you swapped the bytes then multiplied by the original number, it would cycle a long way...

JAL

I never developed for a retrocomputing platform, but was it not possible to seed the random number generator with the cpu clock or uptime or something?

Chenmunka

That's the sort of thing. It was a lot more random than the built in functions, although a lot slower - but speed wasn't the issue, we ran the model overnight.

wizzwizz4

@JAL I might create a reddit account at some point; if I see something going HNQ I'd post there as well as in TNB.

JAL

@wizzwizz4 the programming subreddit is a pretty great source of news. I sometimes look at hacker news as well

wizzwizz4

19:52

@JAL Hacker news. That's the other one.

Chenmunka

@JAL: Yes, you seeded from TIME() or whatever, but that still gave the same grotty pseudorandom sequence that never satisfied the Maths PhDs that were modelling the flow of light in a fibre.

JAL

got it

Chenmunka

Anyway. I have to go now. If I remember where I got the algorithm from, I'll post it.

JAL

Nice talking to you, have a good one o/

Chenmunka

Likewise: TTFN

wizzwizz4

19:54

Bye!

@JAL People have replied to your Reddit post.

JAL

that was quick

RFC 1149.5 specifies 4 as the standard IEEE-vetted random number.

Do we have a policy on posting one-boxes in chat? I know in the SOCVR on Stack Overflow the room owners are generally against them

wizzwizz4

One-boxes are fine, usually.

Our chat's such low-activity that nobody'll mind at the moment, but... in the future that might (read: will hopefully) change.

JAL

fingers crossed!

wizzwizz4

20:11

@JAL I mentioned an email earlier: What do you make of this:

I speak little Spanish, but it looks like the middle column's warning us about a piece of code that breaks the machine.

JAL

huh, that's an interesting find. Where did you get that scan?

wizzwizz4

@JAL An email.

It's a magazine's website, by the looks of it.

Page 32, *_32.jpg... I'll see what else I can find there.

Yes! microhobby.speccy.cz/mhf An index page.

JAL

huh

nice find

wizzwizz4

@JAL Somebody downvoted the Reddit post. :-(

JAL

20:35

ha! It happens, hopefully it gets some more traffic

wizzwizz4

@JAL I got two upvotes after you posted that. ;-)

Hopefully I can rep-cap.

Otherwise I'll be getting lots of reputation slowly, and I don't deserve that yet.

JAL

I got close to hitting the rep cap a few weeks ago, but sadly missed out. Hope to get that badge someday!

wizzwizz4

@JAL Not if I get it first! Mwahahahaha.

Actually, I think SE have a few million of each bronze badge.

Gold badges, however, are more expensive.

There are only a few thousand of those.

JAL

wizzwizz4

You have about 0.2% of all gold badges in existence by that count.

JAL

20:47

damn

I should go for 1% :)

Annoying Robot

21:00

Q: Can a USR command damage a ZX Spectrum?

I recently came across this magazine snippet; specifically this section: Aprovechamos para avisar a los usuarios del Inves, que nos ha Ilegado el rumor de que haciendo: BORDER 5 RANDOMIZE USR 4665 sie averia el ordenador. No hemos tenido aún ocasión de comprobarlo (de funcionar, supond...