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Choroid wrote: BUT I remember reading about "Bank Switching"
So is this still a concept used in a personal computer today?
No. 32 or 64 bit logical addressing removed the need for it.
The problem in the old PCs was the addressing range. Most single-chip CPUs were 8-bit, with 16 bit addresses, so they could only handle 2**16 = 64 Ki bytes of RAM; there was no way to identify any more. Then came the LIM standard for banking: You could set up your system with, say, 48 Ki plain RAM and the upper 16 Ki of the address space handled by a LIM card, providing several 16 Ki blocks (or "banks") of physical RAM, but you could use only one of them at a time. You had to tell the LIM card (through I/O instructions) which of the banks to enable.
You would usually put code, not data, in the banked part: In the un-banked (lower 48 Ki) part, you put a stub that is called from other places. This stub tells the LIM card to enable the right bank where the actual code is placed, and jump to the code address in that bank. If this function called functions in other banks, it would have to call via an unbanked stub to switch to the right bank. Upon return, the previous bank had to be enabled again, to let the caller continue. It did not lead to blazingly fast performance.
Catching data access through a similar stub is not that easy. You could, in an OO world have a object in unbanked RAM with huge data part banked RAM, the object knowing the bank number and address, and channeling all access to it through accessor functions (set, get), but OO was little known in the PC world at that time. I never saw anyone doing this.
LIM was a PC concept. On larger machines, you could see memory overlays, which was also based on routine stubs, but the stub would read a code block from disk into RAM, overwriting anything that was there. You had much more flexibility, but PC disks were so slow in those days that it would have been next to unusable.
You could say that bank switching is a relative of paging mechanisms. I know of at least one family of 16-bit minis providing 64 Ki words (128 Ki bytes) of address space to each user, but could handle up to 32 Mi bytes of physical RAM. So the 64 terminals hooked up to the mini could have their full address space resident in RAM, with no paging. When the CPU switched its attention from one user to another one, it replaced the page table contents to point to the new user's pages - not that different from telling the LIM board to switch to another bank.
You could also say that the 8086 solution, with its segment registers, is a close relative to banking: It allowed direct addressing of up to a mebibyte; this required the instruction to identify the segment register (a parallel to bank number) in every instruction, so it worked even for 'banked' data, not just instructions. (There is a well known quote from the discussions in one big company about how to split that mebibyte between operating system and user segments, and a famous industry leader was quoted for wanting 384 Ki of that space being reserved for the OS, the remaining 640 Ki should be enough for any user program running in 1 Mi of RAM.)
Today, almost every general-purpose machine has at least 32 bit address (4 Gi bytes), 64 bits is becoming the new standard. Then there is no need for neither banking nor overlaying. Rather, the paging system is used to pack the pieces of memory addresses that are actually used into a much smaller physical address space than the logical address space presents to the program.
For special purposes - almost all of it falls under 'embedded' - bit addresses are seen even today. No more than 6-7 years ago, I was working with an 8051, extended with banking hardware for four 16 Ki banks. I believe that chip is still available. (I moved on to another project, so I am not sure.)
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Double WOW and Thank You for the time you put into this reply
A lot of computer design information here
Don't Google LIM Card only found one with LIM Card Computer that is a door relay ? ?
Makes me wonder how the industry made FASTER PC disk's
The quote from the "Famous Industry Leader" I think tells me why Windows 11
needed a new hardware configuration the OS got too big let the end use buy new machines
if they want our OS
I have a Dell T7600 Precision Workstation (Refurbish)
with Xeon E5 2.9GHz 2 processors & 64 GB RAM 64 bit
Graphics Card Nvidia P400 only 2 GB The OEM died Thank goodness for Plug & Play
Windows 7 Pro
It works I do not make any large demands other than VS 2019 and SQLite DB
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My current utilization is: 3 monitors (one playing internet TV); 2 Edge browsers; Outlook; 2 file explorers; 3 different graphics programs; 3 open PDF's; Character Map; 4 - 2022 VS windows; Snipping Tool; 2 image viewers; and Task Manager.
63% memory (out of 16GB)
4% CPU (Ryzen 7)
"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I
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With my 'smart' meter and a few days away from home, I've established that my ambient electricity use averages out at a constant 210w, by which I mean the amount of power I'm using not really do anything at all.
There could be quite a few culprits - fridge-freezer, two security cameras, broadband fibre pick up, router, network switch, roughly eight Alexas (lost count), some smart light-switches and sockets, sockets with USB sockets in them, a smart meter and heaven knows how many things on standby. All only a few watts each but I guess it adds up. Probably the biggest draw is a small weedy PC I use as a home server running Exchange for a load of email accounts.
Anyway, when you add it all up that works out at about £560/year in electricity before you add standing charges and everything else, which would be fair enough if it was my total bill, but this is just the 'before you get started' amount.
I was hoping for some comparisons, and knowing CodeProject is filled with the type of people who know exactly what their baseline energy usage is, thought I'd ask here. 
Regards,
Rob Philpott.
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I had a (so called) smart meter* but since it didn't tell me anything useful I switched it off. So I probably saved 50p a year. As to all those devices in your house  - we have two laptops, and a router on the phone line.
*I thought the actual meter was the smart bit.
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And a fridge, and lots of other things which don't have a proper isolated off switch surely?
I like the smart meter, I can look it at it shake my head and then wander around the house turning all the unused lights off grumbling as I go, like my dad used to.
Regards,
Rob Philpott.
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I really don't need a machine (yet) to tell me when to switch lights on or off. 
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Rob Philpott wrote: £560/year
Ha! At our old house, gas and electric combined was close to that per month! 
We're currently on a £100/month DD for electricity alone - no mains gas in these parts! - and it looks like we used around 350kWh in August, which is the only full month we've been here.
On the plus side, we now have 20 solar panels, and we inherited the "feed-in tariff" which pays based on how much you generate rather than how much you feed back in to the national grid. During the summer months, it looks like we're generating over 480kWh per month, so they're paying us over £340/month for that. Which is nice.
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
modified 8-Sep-23 3:13am.
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Richard Deeming wrote: Ha! At our old house, gas and electric combined was close to that per month!
Ouch. That's serious.
Richard Deeming wrote: so they're paying us over £570/month for that
That's insane, and quite interesting. I know a few people who have panels and the gist of it seems to be they can sell 1KWH for 10p or something, then buy it back later at 35p.
Regards,
Rob Philpott.
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Rob Philpott wrote: I know a few people who have panels and the gist of it seems to be they can sell 1KWH for 10p or something, then buy it back later at 35p.
Yeah, the new FIT is not a patch on the one we inherited. 
As I said, we get paid for everything we generate, even if we don't export any back to the grid. And then we get paid an extra pittance for anything we do export, so if we don't use it all, we end up getting paid twice.
It pays to buy a house from someone who was an early adopter. 
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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You sure about
so they''re paying us over £570/month
?
Your numbers don't look too different to mine (if I pro-rata them for the fact that I have a smaller array) but my payment only comes once every three months - not monthly. I guess you may have a much better deal than I, but three-fold?
Better not hit "Send" on that super-yacht order quite yet . . .
Treading on the toes of giants . . .
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Sorry, I mis-read the dates on the statement. It was actually for 2½ months, so just over £340/month.
Still not a bad little perk though.
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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Phew. For a moment I was worried that I got signed up to a really bad deal.
At least it will cover your standing charge, with some left over.
Just in case anyone else has read this far and is still interested, Richard and Rob's observation that the current deals are much worse than the ones offered in the past is spot on.
Treading on the toes of giants . . .
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Rob Philpott wrote: fridge-freezer,
I would be surprised if the major user was not that. Especially if you do in fact have one of each.
And the older it is the more likely it is that it uses more power.
I believe you can buy a device that monitors it at the plug level. You plug it into the wall and the device plugs into that.
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Gold providing cold ? hole (7)
I've got to go to Shepperton to collect my car from the repair shop so I'll be AWOL for a while
In a closed society where everybody's guilty, the only crime is getting caught. In a world of thieves, the only final sin is stupidity. - Hunter S Thompson - RIP
modified 7-Sep-23 5:09am.
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No matter how much memory I threw at my computer VS 2022 will use all of it...
"If builders built buildings the way programmers wrote programs, then the first woodpecker that came along would destroy civilization." ― Gerald Weinberg
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Agreed. For me, Chrome and VS consume all my PC/laptop's memory, for sure. Not exactly sure why, but it does appear to get worse with newer versions and as time goes by.
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Preloading, caching, and garbage collectors.
All of which contribute to vary aggressive allocations. The upshot is better performance.
Think of it this way - even when your RAM isn't being used, it's still drawing the same power regardless, but it's not doing any useful work.
This way, applications put the RAM to good use - application acceleration essentially - rather than it just sitting idle.
Check out my IoT graphics library here:
https://honeythecodewitch.com/gfx
And my IoT UI/User Experience library here:
https://honeythecodewitch.com/uix
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honey the codewitch wrote: The upshot is better performance
for the application doing the work but maybe not for everything else
The road to madness starts when every application takes the same route
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There is no "everything else" when you are squeezing out the next dev action.
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Well, all versions prior to VS2022 were 32-bit, so they would have been limited to 4GB per instance.
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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Do you mean - good old days? 
"If builders built buildings the way programmers wrote programs, then the first woodpecker that came along would destroy civilization." ― Gerald Weinberg
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By which you mean "the days when VS would crash with an out-of-memory error"?
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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I can't remember that happening so much that to became so annoying as the current situation... Now the computer as whole is stranded...
"If builders built buildings the way programmers wrote programs, then the first woodpecker that came along would destroy civilization." ― Gerald Weinberg
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