Omnimaga
Calculator Community => OTcalc => Discontinued => Major Community Projects => [OTcalc] Z80-Hardware => Topic started by: alberthrocks on August 07, 2010, 04:39:07 pm
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UPDATE: This poll will end tonight. If you haven't already voted, please do so now! (8/9/2010 is the end date!)
UPDATE: Majority says eZ80 50 MHZ, underclockable to 20 MHZ! Voting is now closed. This is now a final feature in OTZ80!
[This is a separate topic to help keep things organized.]
What will the CPU be? It seems everybody has agreed to eZ80, so we'll use that.
What clock speed will we use?
There's only 2 choices here AFAIK (from http://digikey.com/PTM/PTMPartList.page?site=us&lang=en&ptm=6200&WT.z_ptm_structured=Buy%20Now%20Button): 20 mhz or 50 mhz?
So VOTE: eZ80 20 mhz or 50 mhz?
(Ignore the specs about memory for now. We'll decide on them in a later poll.)
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20
Less power usage. The price difference is not great, but for the user, the long-term price difference will be, with all those batteries being wasted.
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edit: I gave a wrong link :O
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Multithreading, guys. It would be really nice, am I right?
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I say 20 mhz. Remember that eZ80 processors are about 4x as efficient as ordinary z80s, so its like having an 80 mhz z80.
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Not to mention if we want to beat TI on the price point every $ saved will matter and make it more accessible to everyone.
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20 mhz is already better than ti's 83's and 84's (albeit by only 5 mhz for the 84's). If we're out there to beat ti, use 20. 50 is a little overkill.
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Moved to Z80 hardware
Also, we have to take in account that TI may respond to us by dropping their prices to something much lower than us if we get popular. This will hurt our sales and force us to stop producing our calcs, allowing TI to re-increase their prices again in countries where there are no laws against monopolys.
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20
Less power usage. The price difference is not great, but for the user, the long-term price difference will be, with all those batteries being wasted.
I can hardly call THAT wasted. With 50mhz we have the world! (okay a little dramatic but read on..it gets more dramatic :P)
why so conservative all? This is a very rare change we have! We want it to be durable right? so make it 50! We could do multitasking (drawing graphs whilst doing 1+1) and much more! The possibilities are far more unbound and the price difference is near nihil. We could easily underclock the calc later anyway and let the user choose betwen slow mode and fast mode. With rechargeable batteries batterties shouldn't be a problem.
We have until now pretty much copied TI, the design "must" be the same, we use the same sort of processors we add some ram. But oh no, no bigger screens please, no faster processors please. I mean really, this is a unique change! We could make the calculator far more then a calculator when choosing 50mhz! It adds to resale value and it costs about $5 more in production.
Will you let slip away yet another change to make this product great?!
I have been noticed that this comment might very well been seen as offending, if that is so then my apologies for its intends were not so. The above was just a act of desperation to get people voting for 50mhz. The "joke" about no bigger screens and no faster processor wasn't aimed at anyone specifically. it's intend was to help others "realize" that up till now 'we' haven't really done anything spectacular with the OTeZ80. This is just my opinion and above are the arguments for supporting it. If anyone felt jumped on by this then I, again, apologise. Just realize that it's intends were not to do so.
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20MHz is already over 5 times as fast as the TI-84+SE.
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It's not that we don't like fast - we do. But keep in mind that this product isn't designed for ourselves - it's for the students and educators. They don't care if it's 50 MHz or 20 MHz. They care about its look, its price, and its functionality.
20 MHz looks pretty good. It's already faster than TI's own calc, but MUCH faster with eZ80 itself.
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Batteries are a huge issue, and multitasking is just dumb for a single purpose embedded device I hate to shoot you and SirCmpwn down but that's just the case. Even at 50Mhz the overhead is not worth it, period, and really as nice as the z80 and eZ80 series procs are I'd almost say we are being dumb for not using something without a FPU built in. An IEEE compliant FPU would make it shit easy to make a calculator that can do all the math we need it to.
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Matthias1992, calm down, and Calc84maniac, isn't it more like 1.333x faster than the TI-84+SE? The TI-84+SE is 15 MHz.
EDIT: Jonimus, would it be as cheap, though?
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Matthias1992, calm down, and Calc84maniac, isn't it more like 1.333x faster than the TI-84+SE? The TI-84+SE is 15 MHz.
Nope, because instructions on eZ80 take less clock cycles than on Z80. It's generally a 1 to 4 ratio. So eZ80 at 20MHz has around the performance of a Z80 at 80MHz.
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Aaah ok, thanks for the info.
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I voted 50 Mhz, since speed is good and if you use rechargeable batteries, battery cost is really not an issue.
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Except many people will use just regular AAAs.
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Schools will not buy armies of rechargeable batteries, so we should just pretend they do not exist.
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Schools will not buy armies of rechargeable batteries, so we should just pretend they do not exist.
Wait, we're marketing this to schools, not users?
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Well, students and schools. But even students won't exactly be tossing rechargeable batteries in - more likely disposable AAA batteries.
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Not everyone will want to have to use rechargeable batteries. I personally will never use them. Some students just don't have the money to spend on them as well as a recharger and will buy the packs of 12-24 cheap batteries at the dollar store nearby instead, as they can buy them regulary with the $2 a month they get from their parents.
In my case, I hate how they last about 3-4 hours then you need to wait 5 hours for them to be recharged. Some people will tell people like me to just buy 3-4 sets of batteries and alternate between then but then comes the money issue above for other people.
What would be nice is if during less CPU-intensive calculations, the calculator clock speed could be changed from 50 to 20 MHz or something like that.
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I keep recommending 50.
The argument that it drains batteries is to my belief false, mostly because of all components in a PC the processor consumes the least. We could better take off the real killer, the screen. Just remove the backlight and add in the juice. I know a calc isn't a pC but just saying proccesor consume little to no power.
The argument that it costs more is also 'debunked' price difference is ~$5
So please vote for 50mhz! It adds greatly to resale value!
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I voted 50MHz. You could underclock the chip to 20MHz in the same manner TI underclocks their calculators, and give the possibility to the user to overclock to 50MHz if he wants more speed in processor-intensive applications. So you would have a 20MHz "power-saving" mode and a 50MHz "Turbo" mode. And, of course, if we want multitasking, we should think accordingly.
Of course, it would be awesome if this 20/50MHz switch would be made with a software, in the same manner my laptop processor underclocks itself from 2GHz to 800MHz when idle.
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I like DJ's idea. As long as there is an option to have a 20 mhz underclocked mode and a 50 mhz over clocked mode, it sounds good to me.
EDIT: changed my vote to 50 mhz/underclocked to 20 mhz.
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my last post didnt get sent apparently, but anyway I voted for 50mhz. I mean really that is like 200mhz in comparison to a z80 right? that is epic! and if it can be underclocked to save on batteries I dont see the problem
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I also changed my vote to 50 mhz. However, this calculator is aimed for "average" students, so make sure it isn't too hard to underclock the processor.
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I keep recommending 50.
The argument that it drains batteries is to my belief false, mostly because of all components in a PC the processor consumes the least. We could better take off the real killer, the screen. Just remove the backlight and add in the juice. I know a calc isn't a pC but just saying proccesor consume little to no power.
The argument that it costs more is also 'debunked' price difference is ~$5
So please vote for 50mhz! It adds greatly to resale value!
It depends of the country. Last time I checked, rechargeable batteries costs around $13 for 2 batteries here. The charger costs $23 and that's if you get the crappiest one. Now if you are a programmer, you need at least 8 batteries (assuming the calc uses 4 at once and you use both sets every day). That makes it $75 total. If for $1.68 you can get 12 cheap disposable batteries and each set of 4 lasts two weeks, after 5 years you spent $50.80 on batteries while with rechargeable ones, you would have spent $75. I gave 5 years as example because rechargeable batteries lasts around 5 years with heavy usage and almost everyone stop using their calcs after 5 years.
So for some people, that $5 would be more like $25. Note that I include taxes in my prices, though. I also live in Canada (Quebec)
Regardless, if the calc can be set to support two CPU speeds, it would be fine, I think. If somebody programs a game, for example, he should probably set it to run in 20 MHz mode for menus and if it's not a very intensive game, I don't think 50 MHz is necessary at all. For math operations, 20 is enough for almost everything except graphing .
Also I changed my vote to 50 MHz.
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I've updated the poll for a clearer option. Revote if needed.
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by too hard, I would say do it completely in software, and no hardware required. I don't know how difficult that would be.
Personally, 20MHZ would be okay, but 50MHZ would be awesome!
Vote changed to the 3rd option.
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I keep recommending 50.
The argument that it drains batteries is to my belief false, mostly because of all components in a PC the processor consumes the least. We could better take off the real killer, the screen. Just remove the backlight and add in the juice. I know a calc isn't a pC but just saying proccesor consume little to no power.
The argument that it costs more is also 'debunked' price difference is ~$5
So please vote for 50mhz! It adds greatly to resale value!
It depends of the country. Last time I checked, rechargeable batteries costs around $13 for 2 batteries here. The charger costs $23 and that's if you get the crappiest one. Now if you are a programmer, you need at least 8 batteries (assuming the calc uses 4 at once and you use both sets every day). That makes it $75 total. If for $1.68 you can get 12 cheap disposable batteries and each set of 4 lasts two weeks, after 5 years you spent $50.80 on batteries while with rechargeable ones, you would have spent $75. I gave 5 years as example because rechargeable batteries lasts around 5 years with heavy usage and almost everyone stop using their calcs after 5 years.
So for some people, that $5 would be more like $25. Note that I include taxes in my prices, though. I also live in Canada (Quebec)
Regardless, if the calc can be set to support two CPU speeds, it would be fine, I think. If somebody programs a game, for example, he should probably set it to run in 20 MHz mode for menus and if it's not a very intensive game, I don't think 50 MHz is necessary at all. For math operations, 20 is enough for almost everything except graphing .
Also I changed my vote to 50 MHz.
Batteries are that expensive? I know you have prices in canadian dollars, but still, I can get a pack of 4 AAAs here for 10 bucks.
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Yeah things over here are generally overpriced, mostly due to import fees and hidden taxes. It's much worse in Ontario apparently, though. I heard a TI-83+ costs $150 there. Over here it's $124 at Staples, both with taxes excluded.
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i don't think having it at 50 is such a bad idea, as long as we would go with the rechargeable lithium battery.
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Oh no, this is going to have AAA replaceable batteries.
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Voted for 50Mhz. If there isn't much of a price difference between 50Mhz and 20Mhz i see no reason not to use the more powerful processor. I also don't see that using a 50Mhz processor would make much of a difference in battery life vs the 20Mhz one.
*Edit* AA batteries might actually be a slightly better option, as they are the same price and voltage, but have a longer charge. Just a thought.
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I agree about AAA batteries. I wouldn't mind the calc being a bit thicker for them. People who want good ones will not have to pay twice the price then. AAA's costs so much compared to AA's, unless you buy them at the dollar store.
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I agree with the AA battery idea. 50 mhz should not be a problem for AA batteries.
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How 'bout the idea of having the calc able to charge Li-Ion rechargeable batteries while plugged into a computer, or something?
Li-Ion AA/AAA batteries, that is.
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Also, do we even know if the eZ80 will be stable when underclocked, without that info it is useless to even think about under-clocking it.
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I'm voting 20. Those who want a fast calc can get the ARM version. Heck, those who want a faster calc than an 84+ can still use the 20. Of course, if the power consumption with the 50 is still about a 10+ hour life, I don't see much point in going for the 20.
And yeah, AA's FTW.
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How 'bout the idea of having the calc able to charge Li-Ion rechargeable batteries while plugged into a computer, or something?
Li-Ion AA/AAA batteries, that is.
Yeah, but how would it know if it was the right kind of battery? eg, not try to charge a non-rechargeable.
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I had to go with 50 mHz. It's like 13.3 times as fast as a TI-84+ if I'm not mistaken.
And AA's would definitely be better than AAA's.
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Either a setting in the OS, or a switch inside the battery pack?
I think you can tell standard from rechargeable through an electrical means, but I don't know how you'd go about detecting nimh/ni cad/li ion
We could always put an internal battery and a crank to charge it. :P
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A setting would be good. I like that idea. Maybe a "If you have rechargeable batteries" type thing.
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I voted for 50 with an option to underclock to 20, its a compromise between the power saving people and the speed junkie people :)
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i change my vote to D batteries with 50 :D.
then i will last even longer than AAA with 20 :P
just my one cent.
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This poll will end tonight. If you haven't already voted, please do so now!
(8/9/2010)
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Majority says eZ80 50 MHZ, underclockable to 20 MHZ! Voting is now closed. This is now a final feature in OTZ80!
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I changed it in the hardware section on the wiki.
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@graphmastur: Great, thanks! :) I'm also having a thread here for others to easily keep track.
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Sounds good, seemed like the best option out there imho :) a compromise for both ^^
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Have you guys checked if that type of processor can be underclocked at all, though? I know the TI-83+SE processor can be, same for the TI-Nspire ARM processor, though.
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Bump, again.
Anyways I think we might want to reconsider
eZ80 @ 50 mhz vs propellor octa-core @ 80 mhz
Not that multitasking is a must but with the propellor chip we have
8 true indepedent cores running @ 80 mhz with 20 mips per core
Full 32 bit math
Video/tv out support
Audio jack out support
Possible vga and ps2 support
I saw an sdram extension kit for 32mb of ram BUT someone came up with this brilliant sd card which can connect to wifi...yea that is right wifi! And guess what, propellor can easily interface with an SD card!
We could even have, say, 2 system management dedicated cores and then 6 free stream cores...
It costs. $8 (pfq44)
Nearly nothing...
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wow, that octa-core sounds sick O.O
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I don't really see a point in maintaining z80 compatibility, considering it would be illegal to include an 84+ emu anyways (unless it had kOS on it)
Really, anything would work fine, if it had the power. The propeller fits those needs, and would be highly programmable, considering it's a very popular dev board right now.
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I don't really see a point in maintaining z80 compatibility, considering it would be illegal to include an 84+ emu anyways (unless it had kOS on it)
It's not illegal if it ships without a ROM (or with kOS, of course) and you have to provide your own, I think.
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wow, that octa-core sounds sick O.O
Can you imagine the headache of writing assembly for a multi-core processor?
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Wait, this project plans to emulate a TI-8x? I thought we just wanted to maintain compatibility so that we could interact with it and because most of us here are familiar with ARM or Z80. I personally love the Z80 :D
So if we use a Z80 that is backwards compatible and KOS is made for this and the TI calcs, then that means we could start making assembly programs compatible on both platforms. The only issue would be directly playing with ports... KOS would need to make ROM calls that functioned differently to handle port reading/writing properly (but with the same address). Then we could start making KOS programs for the 83+/84+ that work on OTZ80.
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Considering the specs on those chips, why not make uberspire OT-arm, and make OT-octa?
Also, I don't care much about cross-compatibility. I don't want a calc that works with TI in everything. That's called a TI-calc. We want awesome calcs. I can see emulating the pages and stuff.
@matthias: Do you have a really good link to that?
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http://www.parallax.com/propeller/
We could also wait for the propellor two which is far more powerfull and comes at the same price (at least, I thought I read that somewhere).
As for z80 compatibility a z80 core emulator has already been written for the propellor, it is however as far as I know written in SPIN which is the interperted language for the propellor.
Prop. ASM might not exactly be a breeze but the community is very helpfull and very knowledgeable, hell, even the chip designers get in to some topics everry now and then.
And grapmastur, I think we should do one calc at the time, lets start with the easy one, gain experience with the whole process and then make the second one if the prev. one was a succes...
Just my three cents :)
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Okay, we could do one calc at a time. And starting with a z80 based calc would be very nice I presume.
Okay. I'll go over the supply list again. Is anyone good at designing electronic schematics? It's definitely not my skill. Open source design programs would be nice like eaglescad I think is free. Something like that. Or even a .pdf of your circuit describing it. But yeah, that's a little farther ahead.
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I don't really see a point in maintaining z80 compatibility, considering it would be illegal to include an 84+ emu anyways (unless it had kOS on it)
It's not illegal if it ships without a ROM (or with kOS, of course) and you have to provide your own, I think.
Also the emu doesn't have to come with the calc. It can be separate.
And yeah I agree the focus should be put on one calc. Since uberspire is working on Ubercalc, let's focus on OTZ80 next Summer so more energy can be put in it.