Author Topic: eZ80 Hardware Discussion (Read 57751 times)

matthias1992 · « **on:** August 07, 2010, 06:34:57 am »

I suggest we discuss here about the best hardware for the eZ80 version. Well, the processor is already pretty much decided isn't it?

Processor: eZ80
RAM: ?
(Flash)ROM: ?
LCD: ?
LCD Driver: ?
Keypad (view details below): ?
Linkport (view details below): ?

(S)(D)RAM details: how much ram, how fast/slow read write cycle and which manafacturer?
(Flash) ROM: how much ROM? do we want Flash ROM or just "regular" ROM? read/write cycle? manafacturer?
LCD: resolution? refresh rate? manafacturer? (I keep asking that because we don't want to cheaply made crap that breaks easily)
LCD Driver: buffer size? r/w cycle? manafacturer? compatibilty with LCD (pretty much a must)?
Keypad details: specifically how many keys and seperate keys for letters? or a alpha mode switch like on the TI83/84+(SE)?
Linkport details: do we want a old IO port (probaly not) or mini-usb, or even 'full' usb? and do we want a mini-jack for the sound? or something else? someone even suggested SD-card compatibilty...

I probaly forgot some important stuff but this is all I can think of now.

Happybobjr · « **Reply #1 on:** August 07, 2010, 07:58:28 am »

i don't think we need a sd card support. unless it comes for free, i wouldn't bother?
its a calculator, what would people need an sd card for.

mapar007 · « **Reply #2 on:** August 07, 2010, 09:35:45 am »

~~SDRAM != SD card iirc.~~ EDIT: nevermind, I missed the last sentence

Maybe we can pick the same Flash chip as TI's, it's not that crappy and it's cheap. We DEFINITELY need another LCD though

SirCmpwn · « **Reply #3 on:** August 07, 2010, 10:29:58 am »

A 96x65 screen would make me very happy

Also, like I said in the other thread, I think that I/O linking should be done via a headphone jack, because there is already a huge number of cables that would fit it, and it would be easier for sound to implement as well.
A mini-usb jack would be nice. So would specifically gearing the keyboard to work well with KOS, so we might want to make that a last minute decision.

matthias1992 · « **Reply #4 on:** August 07, 2010, 10:54:56 am »

I think we want more then 96x65, personally I am in favor of QVGA which is 320x240. It isn't neccesarily more expensive and adds greatly to the overall feeling. I believe I said it somewhere else already but I think if this will run KOS it should run a upgraded version of it which takes full use of new instructions and the 4x greater speed. Sorry, I know it is quite a pain to write a OS let stand having to 're' write it, you can always you KOS Z80 as a reference and bse for KOS eZ80 though. Rogue shouldn't be too hard to port over right? I think we are aiming for something Nspirish but cooler, faster and in general just better. I am in favor of your IO headphone jack though.

jnesselr · « **Reply #5 on:** August 07, 2010, 10:57:02 am »

Can we change this conversation title to start with z80? I just think it would be better not to get confused.

Okay, For the z80, 96x64 is fine. 65 is too much. 96x64 is a 3:2 ratio.

I agree with the link port, sir, and I am liking the mini usb option. I don't like SD card compatibility, though.

@matthias: maybe a bigger screen, but then again, this is to go against the TI-8x series. The arm is supposed to go against the Nspire.

SirCmpwn · « **Reply #6 on:** August 07, 2010, 11:00:35 am »

Well, I will have to modify KOS to work on an eZ80 in the first place, I was just shooting for compatibility with TI KOS programs. GUI programs will be compatible just fine, but I'm worried about programs that request full LCD and RAM access.

fb39ca4 · « **Reply #7 on:** August 07, 2010, 11:08:50 am »

The newer HP-50gs have sd card slots, so even though this is a calc, we shouldn't rule it out.
Also, what will the form factor be? 84 sized or Voyage 200? If it ends up being v200 sized we can always put a "DVORAK" keyboard, and still have it allowed on tests.

SirCmpwn · « **Reply #8 on:** August 07, 2010, 11:11:49 am »

Well, not many people know how to use a DVORAK keyboard. A lot of people use QWERTY, and a lot of people use ABCDE. People will know where to find their letters with ABCDE or QWERTY. Since QWERTY is ruled out, ABCDE seems the way to go.
Plus, I personally don't like DVORAK

alberthrocks · « **Reply #9 on:** August 07, 2010, 11:13:55 am »

@matthias1992: No QVGA. That's a bit too big, especially for this kind of calculator.
No worries though - you'll get a big screen for the ARM based calc (OTARM)!

@fb39ca4: Maybe, but no one uses HPs these days. Many students use TI, and then seeing a SD card slot will make it look weird. Just my 2 cents.

Also, this will be an 84 sized calc, with a similar build to it.
------------------------
In general, some thoughts:

1) SD slots are really not needed. I just can't envision anyone who would really want to do that. And besides, this is a calculator, not a phone/iPod Touch.

2) Mini USB is great. You could also put in a regular USB lead to allow USB devices and such. Of course, that's optional, and we still have to stick to "It's a calculator" rules.

3) Link port works perfectly (with the speaker jack size). I also suggest including a regular link to link cable, USB mini to USB mini cable, and an adapter to work with the TI calcs. (Adapter is optional, you can debate on whether or not to support it)

4) ABCDE is my preference. Not many people know the DVORAK format anyway, so why confuse them with it?

5) There was also a mention of a nice backlight, which would be a really cool idea to use. The OP (matthias1992) might want to include that in the list.

fb39ca4 · « **Reply #10 on:** August 07, 2010, 11:27:42 am »

I think a qvga screen would be fine. The nspire has that resolution. However, if it makes the physical dimensions too big, we could go a smaller, maybe 192x128 or 240*160. With any screen, native graysacle is a must.

alberthrocks · « **Reply #11 on:** August 07, 2010, 11:33:46 am »

@fb39ca4: Are you sure you're talking about the right device? The OTZ80 will have to stay the same as the regular TI-8x series screen.
The OTARM (this topic is OTZ80) will compete with the Nspire, and have a nice colorful screen

The OTZ80 will have a small screen WITH grayscale.

nemo · « **Reply #12 on:** August 07, 2010, 12:02:03 pm »

dvorak being ruled out = me sadface. but i understand, it *would* confuse people, so i vote for ABCDE.

i'm thinking the screen resolution should be larger than 96x64, we don't want to mimic TI, we want an upgraded calculator. i'm thinking either 128x96 or 160x128 are ideal.

alberthrocks · « **Reply #13 on:** August 07, 2010, 12:12:25 pm »

I'm still not sure about that though. We actually need to mimic TI to get the calculator to sell. If it's cheaper but doesn't look like a TI-8x, people will think it can't do anything.

As for screen size, I still think the 96x64 is a good size to work with.
Since we want the old TI programs and others to still run, how are you going to do that with a bigger screen?
Centering it isn't exactly interesting, nor is scaling it up.

SirCmpwn · « **Reply #14 on:** August 07, 2010, 12:54:13 pm »

Yeah, centering is not fun. iPod apps on the iPad, anyone?

Author Topic: eZ80 Hardware Discussion (Read 57751 times)

matthias1992

eZ80 Hardware Discussion

Happybobjr

Re: Hardware Discussion

mapar007

Re: Hardware Discussion

SirCmpwn

Re: Hardware Discussion

matthias1992

Re: Hardware Discussion

jnesselr

Re: Hardware Discussion

SirCmpwn

Re: Hardware Discussion

fb39ca4

Re: Hardware Discussion

SirCmpwn

Re: Hardware Discussion

alberthrocks

Re: Hardware Discussion

fb39ca4

Re: Hardware Discussion

alberthrocks

Re: Hardware Discussion

nemo

Re: Hardware Discussion

alberthrocks

Re: Hardware Discussion

SirCmpwn

Re: Hardware Discussion