Modern day RAM, static or dynamic?
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Back in the days I knew about hardware there were two types of RAM, the cool static RAM which does exactly what RAM should, and the far more common dynamic which needed refreshing. If I remember correctly, each bit was a tiny capacitor which would slowly leak charge so periodically you'd have to recharge it. The bits were arranged in a grid of rows and columns and there was some concept of RAS and CAS (Row/Column address select) but can't remember the details. That was nearly 30 years ago now I think about it. So, can anyone tell me how it's done these days? I suspect dynamic RAM is a thing of the past. And who can remember wiping the non-volatile memory of the day with UV light? I feel quite nostalgic.
Regards, Rob Philpott.
Rob Philpott wrote:
And who can remember wiping the non-volatile memory of the day with UV light? I feel quite nostalgic.
Never actually used them... just remember them from school :laugh:
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Rob Philpott wrote:
And who can remember wiping the non-volatile memory of the day with UV light?
Oh yes! 8 KByte (and later 32 KByte) EPROMs in "the cooker" once you'd cleaned all the glue the little labels left on the quartz window...straightening the legs out and hoping none of them fell off. Swearing when they did. And the joy of getting a small tool to "hook" on the leg-free ends on the chip to remove it instead of wiggling a screwdriver under it and levering it up!
The universe is composed of electrons, neutrons, protons and......morons. (ThePhantomUpvoter)
Oh the joy, I've returned to that era as I'm doing embedded projects and relearning the hardware so a small screw driver is a major tool in the old kit. In fact I pulled an EPROM out of an old printer the other day and got most of the glue off but gave up after a while.
VS2010/Atmel Studio 6.1 ToDo Manager Extension Some days, it's just not worth chewing through the restraints.
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Rob Philpott wrote:
And who can remember wiping the non-volatile memory of the day with UV light?
Oh yes! 8 KByte (and later 32 KByte) EPROMs in "the cooker" once you'd cleaned all the glue the little labels left on the quartz window...straightening the legs out and hoping none of them fell off. Swearing when they did. And the joy of getting a small tool to "hook" on the leg-free ends on the chip to remove it instead of wiggling a screwdriver under it and levering it up!
The universe is composed of electrons, neutrons, protons and......morons. (ThePhantomUpvoter)
OriginalGriff wrote:
straightening the legs out and hoping none of them fell off. Swearing when they did. And the joy of getting a small tool to "hook" on the leg-free ends on the chip to remove it instead of wiggling a screwdriver under it and levering it up!
I do this all the time when I'm using IC's :) I've developed quite knack of wiggling them out with almost no leg bending at all :laugh:
.-. |o,o| ,| \_\\=/\_ .-""-. ||/\_/\_\\\_\\ /\[\] \_ \_\\ |\_/|(\_)|\\\\ \_|\_o\_LII|\_ \\.\_./// / | ==== | \\ |\\\_/|"\` |\_| ==== |\_| |\_|\_| ||" || || |-|-| ||LI o || |\_|\_| ||'----'|| /\_/ \\\_\\ /\_\_| |\_\_\\ -
Rob Philpott wrote:
And who can remember wiping the non-volatile memory of the day with UV light?
Oh yes! 8 KByte (and later 32 KByte) EPROMs in "the cooker" once you'd cleaned all the glue the little labels left on the quartz window...straightening the legs out and hoping none of them fell off. Swearing when they did. And the joy of getting a small tool to "hook" on the leg-free ends on the chip to remove it instead of wiggling a screwdriver under it and levering it up!
The universe is composed of electrons, neutrons, protons and......morons. (ThePhantomUpvoter)
Those were the days! The great thing about that period was those who were involved were all enthusiasts, whereas the whole IT industry these days is populated by people who see is as a career armed with their book on design patterns, and have literally no idea what's going on at lower levels.
Regards, Rob Philpott.
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Those were the days! The great thing about that period was those who were involved were all enthusiasts, whereas the whole IT industry these days is populated by people who see is as a career armed with their book on design patterns, and have literally no idea what's going on at lower levels.
Regards, Rob Philpott.
I fully agree with you on this, as I come from both an electronic and computer background, and therefore I'm really interested in embedded systems and all the low level stuff.
.-. |o,o| ,| \_\\=/\_ .-""-. ||/\_/\_\\\_\\ /\[\] \_ \_\\ |\_/|(\_)|\\\\ \_|\_o\_LII|\_ \\.\_./// / | ==== | \\ |\\\_/|"\` |\_| ==== |\_| |\_|\_| ||" || || |-|-| ||LI o || |\_|\_| ||'----'|| /\_/ \\\_\\ /\_\_| |\_\_\\ -
You mean one of these 2708 (1K X 8 EEPROM)[^]. I could be wrong, and am on many an occasion but I believe DRAM and SRAM work pretty much the same as in yesteryear.
VS2010/Atmel Studio 6.1 ToDo Manager Extension Some days, it's just not worth chewing through the restraints.
Wow. They still make them. I have to say the 2708 doesn't ring any bells, but I suspect it might be the little brother to a 2764 which might have the same pin-outs as a 6264! What use could such a thing be these days? Educational if the only thing I can think of.
Regards, Rob Philpott.
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Oh the joy, I've returned to that era as I'm doing embedded projects and relearning the hardware so a small screw driver is a major tool in the old kit. In fact I pulled an EPROM out of an old printer the other day and got most of the glue off but gave up after a while.
VS2010/Atmel Studio 6.1 ToDo Manager Extension Some days, it's just not worth chewing through the restraints.
IMS is a good 'un for that (Industrial Methylated Spirits 95% denatured so it can't be drunk). Most glues respond well to it, but for the really stubborn ones I liked trichloroethane. Until they banned it... :(
The universe is composed of electrons, neutrons, protons and......morons. (ThePhantomUpvoter)
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Those were the days! The great thing about that period was those who were involved were all enthusiasts, whereas the whole IT industry these days is populated by people who see is as a career armed with their book on design patterns, and have literally no idea what's going on at lower levels.
Regards, Rob Philpott.
Rob Philpott wrote:
a career armed with their book on design patterns
...and firmly ensconced in their Ivory Towers...
The universe is composed of electrons, neutrons, protons and......morons. (ThePhantomUpvoter)
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Back in the days I knew about hardware there were two types of RAM, the cool static RAM which does exactly what RAM should, and the far more common dynamic which needed refreshing. If I remember correctly, each bit was a tiny capacitor which would slowly leak charge so periodically you'd have to recharge it. The bits were arranged in a grid of rows and columns and there was some concept of RAS and CAS (Row/Column address select) but can't remember the details. That was nearly 30 years ago now I think about it. So, can anyone tell me how it's done these days? I suspect dynamic RAM is a thing of the past. And who can remember wiping the non-volatile memory of the day with UV light? I feel quite nostalgic.
Regards, Rob Philpott.
Both. Caches on the CPU are usually static RAM, and the RAM that's referred to as RAM is practically always dynamic RAM (there are some weird other techs out there like phase change RAM, not seen in PCs as of yet) otherwise it would be huge and cost millions. 8GB of static RAM? You wish.
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Wow. They still make them. I have to say the 2708 doesn't ring any bells, but I suspect it might be the little brother to a 2764 which might have the same pin-outs as a 6264! What use could such a thing be these days? Educational if the only thing I can think of.
Regards, Rob Philpott.
Embedded systems use it to keep config data, fonts, etc.. The Microcontroller that I'm using[^] only has 1K EPROM.
VS2010/Atmel Studio 6.1 ToDo Manager Extension Some days, it's just not worth chewing through the restraints.
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IMS is a good 'un for that (Industrial Methylated Spirits 95% denatured so it can't be drunk). Most glues respond well to it, but for the really stubborn ones I liked trichloroethane. Until they banned it... :(
The universe is composed of electrons, neutrons, protons and......morons. (ThePhantomUpvoter)
All I have is Isopropyl (sp?), come to think of it I've got some mineral spirits that might do the trick?
VS2010/Atmel Studio 6.1 ToDo Manager Extension Some days, it's just not worth chewing through the restraints.
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Both. Caches on the CPU are usually static RAM, and the RAM that's referred to as RAM is practically always dynamic RAM (there are some weird other techs out there like phase change RAM, not seen in PCs as of yet) otherwise it would be huge and cost millions. 8GB of static RAM? You wish.
Interesting point. I had (without much consideration) thought that dynamic RAM would probably have been succeeded by something newer and better. But for static if you can make a single bit out of two logic NANDS (or something like that - can't remember) with say 8 transistors then as you say for 8GB you are talking about one unattainable level of chip fabrication. Obvious really, when you think about it.
Regards, Rob Philpott.
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Embedded systems use it to keep config data, fonts, etc.. The Microcontroller that I'm using[^] only has 1K EPROM.
VS2010/Atmel Studio 6.1 ToDo Manager Extension Some days, it's just not worth chewing through the restraints.
They're awesome things - a whole computer with a wide selection of IO on chip! Very smart. But why I would question use 8 bit architecture these days? Either cost or power consumption I guess but neither would be that much of a problem. Aha, maybe because you need a compact instruction set to fit in small amounts of memory? Use more memory! I bought a Raspberry PI recently and that just goes to show what you can get for 20 quid these days. Although all I've done is stare at it so far. Totally awesome - I just don't know what to do with it.
Regards, Rob Philpott.
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Embedded systems use it to keep config data, fonts, etc.. The Microcontroller that I'm using[^] only has 1K EPROM.
VS2010/Atmel Studio 6.1 ToDo Manager Extension Some days, it's just not worth chewing through the restraints.
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They're awesome things - a whole computer with a wide selection of IO on chip! Very smart. But why I would question use 8 bit architecture these days? Either cost or power consumption I guess but neither would be that much of a problem. Aha, maybe because you need a compact instruction set to fit in small amounts of memory? Use more memory! I bought a Raspberry PI recently and that just goes to show what you can get for 20 quid these days. Although all I've done is stare at it so far. Totally awesome - I just don't know what to do with it.
Regards, Rob Philpott.
in embedded systems it's all about minimizing production cost. You want to sell houndreds (or thousands) of this systems. so every dollar will count in the end. if you can get a microcontroller for 10$ which does the job. why get one for 15$?
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Back in the days I knew about hardware there were two types of RAM, the cool static RAM which does exactly what RAM should, and the far more common dynamic which needed refreshing. If I remember correctly, each bit was a tiny capacitor which would slowly leak charge so periodically you'd have to recharge it. The bits were arranged in a grid of rows and columns and there was some concept of RAS and CAS (Row/Column address select) but can't remember the details. That was nearly 30 years ago now I think about it. So, can anyone tell me how it's done these days? I suspect dynamic RAM is a thing of the past. And who can remember wiping the non-volatile memory of the day with UV light? I feel quite nostalgic.
Regards, Rob Philpott.
I just know to keep static away from all RAM.
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in embedded systems it's all about minimizing production cost. You want to sell houndreds (or thousands) of this systems. so every dollar will count in the end. if you can get a microcontroller for 10$ which does the job. why get one for 15$?
Very fair point! It amazes me what you can get in birthday cards these days...
Regards, Rob Philpott.
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Very fair point! It amazes me what you can get in birthday cards these days...
Regards, Rob Philpott.
Rob Philpott wrote:
It amazes me what you can get in birthday cards these days...
And clothing!
VS2010/Atmel Studio 6.1 ToDo Manager Extension Some days, it's just not worth chewing through the restraints.
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Nope. That microcontroller has EEPROM ;)
Ok you got me on that one it is electrically erasable, but I'm just accustomed to EPROM...plus it's almost 5AM and I've been up all night.
VS2010/Atmel Studio 6.1 ToDo Manager Extension Some days, it's just not worth chewing through the restraints.
-
Back in the days I knew about hardware there were two types of RAM, the cool static RAM which does exactly what RAM should, and the far more common dynamic which needed refreshing. If I remember correctly, each bit was a tiny capacitor which would slowly leak charge so periodically you'd have to recharge it. The bits were arranged in a grid of rows and columns and there was some concept of RAS and CAS (Row/Column address select) but can't remember the details. That was nearly 30 years ago now I think about it. So, can anyone tell me how it's done these days? I suspect dynamic RAM is a thing of the past. And who can remember wiping the non-volatile memory of the day with UV light? I feel quite nostalgic.
Regards, Rob Philpott.
I remember being shown inside the memory cabinet where you could clearly see the cores and the wires going between them. The system also had a loudspeaker which made sounds according to the instructions being executed, so you could tell what stage a long program was at, and also if it was looping.
Use the best guess
