The Z80 spawned the 64180 which was a Z80 with loads of stuff built in (from Wikipedia)
Execution and bus access clock rates up to 10 MHz
Memory Management Unit supporting 512K bytes of memory (one megabyte for the HD64180 packaged in a PLCC)
I/O space of 64K addresses
12 new instructions including 8 bit by 8 bit integer multiply, non-destructive AND and illegal instruction trap vector
Two channel Direct Memory Access Controller (DMAC)
Programmable wait state generator
Programmable DRAM refresh
Two channel Asynchronous Serial Communication Interface (ASCI)
Two channel 16-bit Programmable Reload Timer (PRT)
1-channel Clocked Serial I/O Port (CSI/O)
Programmable Vectored Interrupt Controller
As a consequence it was really popular in the 90s as an embedded processor just when I was starting my career. This lead to me writing thousands of lines of Z80 assembly. You could program it in C but the compiler was useless at making stuff go fast.
One of those things I wrote was an LZ77 decompressor used in a satellite broadcast system. It took me about a week to write it, test it and optimise it. Quite a challenge! I remember optimising it about the LDIR instruction to copy memory.
The compressor was written in C and ran on the PCs of the day.
I love photorec and dd rescue. I have recovered many many disks and memory cards with it.
I even recovered a card that had been off to professional recovery and deemed unrecoverable. I think half the memory chips in the card were fried so I used DD rescue to recover what data I could and then photorec to sift the wreckage. The owner was delighted to receive some of the photos.
If you ever have to do this, use DD rescue to image the source media as a first step. Sometimes you don't get a second read!
You say it. A few years ago my homeserver behalved odd and i needed reboots. I took out the SSD, used dd-rescue and after that The SSD did not even show up as storage any more. Yhea. I also have backups since then. :)
A nuclear power plant cannot free all of its energy at once as the fuel enrichment is too low for an exponential excursion of power, i.e. an explosion.
Batteries tend to burn instead of explode. Same energy, but released over much more time. And while an uncontained battery fire is a huge issue in a private home or in a car park because of how difficult they are to control, in a dedicated battery storage plant you can just let it burn down
It's not without risk, but as far as power plants go it's pretty low risk
In physics, whenever you make a measurement it has a precision. Usually you represent this as a normal distribution, but for calculations it can be easier to represent this as an interval.
The police measure the distance my car travelled [ 99.9, 100.1 ] m and the time it took [ 3.3, 3.4 ] s - how fast was my car going? [29.38, 30.33] m/s according to the interval calculator.
Physics students learn exactly this method before they move on to more sophisticated analysis with error distributions.
> Her 3.5 foot by 3.5 foot solar panel weighs about 25 pounds and is a half-inch thick. It can harvest about 220 watts of energy from the sun each day.
Grrrr. Watts is not a unit of energy.
As a holder of a physics degree this annoys me quite a lot. Journalists seem to have trouble keeping track of energy vs power. It's like saying my friends house is 5 miles per hour away.
> Her 3.5 foot by 3.5 foot solar panel weighs about 25 pounds and is a half-inch thick. It can harvest about 220 watts of energy from the sun each day. It’s on the smaller end of available balcony solar panels. The panels can go up to almost 2,000 watts in capacity. A 1,200-watt panel is enough to power a window air conditioner unit, according to Bright Saver.
This whole paragraph is nonsense. A 2,000 watt panel is never going to go on a balcony (because it is huge for any residential balcony), and regardless of "capacity" a solar panel is not going to power a window AC unit without an intermediate storage, unless you want the compressor to shut down every time a cloud passes by.
And people complain about writing being AI generated. Is this kind of sloppy writing any better?
But I think plug-in / balcony solar will be pretty cool. And I think there's a path to inexpensive, larger, safer grid-tie inverters which never backfeed, but prioritize solar input first and make up the difference with grid power.
For example, I'm imagining a box that would plug in to the wall, have a DC input from solar panels, and a power strip for loads supporting up to, ideally, a full 15A normal US 120V circuit.
Currently this box exists in the form of battery power station units (Bluetti, Ecoflow, Anker etc). But I think there could be a much less expensive form that could exist without the battery.
1lb/kg is a unit of acceleration approximately equal to 4.448m/s^2. Pound of weight, not mass, obviously. This is still more valid than almost anything in the American Journalist system of units!
>As a holder of a physics degree this annoys me quite a lot. Journalists seem to have trouble keeping track of energy vs power. It's like saying my friends house is 5 miles per hour away.
I've ranted endlessly about the outsized impact people with no expertise but a large audience have had on society. So so many people have the worldview shaped by individuals that cannot even bother to learn basics like watts and watt-hours for their "reporting".
With storage the watts are also important because it is a measure of how much power it can replace from other power plant sources which are also measured in watts. Admittedly, the time it will last is omitted, so a full energy calculation can't be done, but at least you know how many dirty peaker plants it replaces.
I think it is conceptually the same but multiple PRs gives you the tools to manage the commits properly which GitHub is missing. You can't do the equivalent of `git rebase -i` in the GitHub UI to squash a fixup into a previous commit. Having each change in it's own PR enables that workflow using the existing GitHub UI.
I can, but I wouldn't describe having two two-ball capable hands as being half-way there. If forced to put a number on it, something like 20% is the best I could do.
Sure! Juggle two in dominant hand. Then two in weak hand. Then two plus one both ways round, then 4. That's how I used to teach people anyway. Balls go up on the inside and down on the outside. For most people two really well in non dominant hand is the hard part.
I came in and out of 'actively juggling' through time, but I was at least 20 years with strong two in my off hand before four really started to do four for any real number of throws.
The perpetual issue was that the loops move in and out of sync, so the rhythm of responsibilities ends up with beat patterns that confuse my focus.
I always felt that 4 wasn't a huge step up from 3 for most people, especially given the right tips. If you learn 3 in a day or two then 4 is a week or two. That kind of thing.
A good trick to practice 4 is to throw 4 throws in the middle of 3. So you juggle 3 balls then throw one to the same hand (the 4 throws) while holding a ball in the other for a beat (the 2 throws). You can put the 42 throws anywhere in the 3 pattern and if you do it as quickly as possible you get 423 which is an interesting pattern. 441 is good too - harder but helps with that sync problem.
The big step comes at 5. It took me nearly a year to master 5 balls with consistent practice. I eventually got reasonably good at 6 balls (juggled in sync, crossing over) but that's where I plateaued as far as numbers go.
There are lots of other things than numbers though. Non jugglers will have no idea how many balls you are juggling so you can impress with 3 balls. My favourite party trick was blindfold juggling. I used to be able to juggle 3 balls for about a minute like that.
Juggling two with the non-dominant hand is so hard. Much harder than juggling three balls. There's something fundamentally different about using your non-dominant hand independently as opposed to in coordination with your dominant hand. I can use my left for many things: juggling, typing, playing guitar etc., but as soon as I try to do it with my right hand behind my back I feel incredibly weak.
It would be so useful to have two right hands. I'm curious whether you think getting over the hump helps with ambidexterity in general.
Something I learnt was when learning new juggling tricks, make sure to practice them both ways round. For example if you are learning to shower 3 (round in a circle juggling) make sure you practice the high throws with your right and left hands. It gets easier the more you do it so I guess that it does help with ambidexterity.
I may try that. I can do two balls in either hand already. I just never tried doing it in both hands at once.
Strangely even though I'm right-handed I feel more comfortable juggling two in my left hand. I also bat and golf left-handed so sometimes I wonder if my parents forced right-handedness was on me.
My favourite technique is after the initial two ball crosses was for me to stand in for their left (or non dominant) hand.
You stand slightly behind your pupil and get them to put their left hand behind their back and you put your left hand about where theirs should be. You give them one ball in their right hand and then you start the pattern with two balls.
Most people are amazed to find themselves juggling at this point. Yes, you are correcting their mistakes but it gives a real feeling of juggling for them. Most people manage 10 catches quite easily at this point.
Once they have the hang of that swap sides. This one is harder, don't do it too long before setting them off on 3 and they can practice themselves from here on.
I have taught 100s of people to juggle like that :-)
Some of us had a juggling party at a lake. All amateurs, i.e. few could manage much with clubs. An international juggling award winner (don't remember more than that) found out, joined us, and had a number of us partner juggling flaming torches pretty quickly, and kept pushing us into more and more techniques. The quality of the coach matters!
That's a neat approach! It's not really the same, but it kind of reminds me of an interview they did with Michael Moschen (the guy who performed the contact juggling scene in Jim Henson’s movie Labyrinth). He talked about how difficult it was because he had to thread his arms underneath David Bowie’s, so he couldn’t actually see the acrylic ball while he was doing the contact juggling.
Execution and bus access clock rates up to 10 MHz
Memory Management Unit supporting 512K bytes of memory (one megabyte for the HD64180 packaged in a PLCC)
I/O space of 64K addresses
12 new instructions including 8 bit by 8 bit integer multiply, non-destructive AND and illegal instruction trap vector
Two channel Direct Memory Access Controller (DMAC)
Programmable wait state generator
Programmable DRAM refresh
Two channel Asynchronous Serial Communication Interface (ASCI)
Two channel 16-bit Programmable Reload Timer (PRT)
1-channel Clocked Serial I/O Port (CSI/O)
Programmable Vectored Interrupt Controller
As a consequence it was really popular in the 90s as an embedded processor just when I was starting my career. This lead to me writing thousands of lines of Z80 assembly. You could program it in C but the compiler was useless at making stuff go fast.
One of those things I wrote was an LZ77 decompressor used in a satellite broadcast system. It took me about a week to write it, test it and optimise it. Quite a challenge! I remember optimising it about the LDIR instruction to copy memory.
The compressor was written in C and ran on the PCs of the day.
reply