W. H. Heydt
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Re: Something I'd like to see.

Sat Jul 20, 2019 11:30 pm

Bakul Shah wrote:
Sat Jul 20, 2019 9:10 pm
W. H. Heydt wrote:
Sat Jul 20, 2019 4:59 pm
Some of the folks in the CM forum were practically drooling over the prospect getting access to a PCIe lane. Unfortunately, some of them seemed to think that there were multiple PCIe lanes (if only...).
There are PCIe expansion switch devices: 1 upstream, 2 or more downstream ports. This can be put on CM board as I suggested or on the backplane or an IO module board. CM4’s edge connector layout would not be compatible to older CMs so there is an opportunity to think through and come up with a design that can last for a few more Pi generations and allow for new uses. I’m sure Eben Upton & co are well aware of this.
I'm sure they are, and that they are well aware of a great many possibilities. The problem with doing a line expansion on the single PCIe is that you're back at the same problem the Pis prior to the Pi4B had. You have a single, limited capacity line into the SoC. No matter how much stuff is at the other end, it's all got to get down to that single line at some point. It comes down to moving the bottleneck around, not eliminating it.

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Gavinmc42
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Re: Something I'd like to see.

Sat Jul 20, 2019 11:45 pm

Hahahahahahahaha. "Next to no R&D". You have no idea how much pain it took to get those right!!
Yep and I think within a month some has hacked the keyboard and shoved in a Zero and then a 3A+.
I was thinking at the time, lucky they had enough room ;)

RPF keyboard+ case with officially designed space for a CM4 plus PCIe/M.2 drive?
Mechanical keyboard?
Built like the old IBM buckling springs indestructible keyboards.
A RPF keyboard/Pi case that can be passed down the generations.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

Bakul Shah
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Re: Something I'd like to see.

Sun Jul 21, 2019 12:26 am

W. H. Heydt wrote:
Sat Jul 20, 2019 11:30 pm
The problem with doing a line expansion on the single PCIe is that you're back at the same problem the Pis prior to the Pi4B had. You have a single, limited capacity line into the SoC. No matter how much stuff is at the other end, it's all got to get down to that single line at some point. It comes down to moving the bottleneck around, not eliminating it.
It looks like BMC2711 has a PCIe 2.0 interface. That can do 5 GT/s or 500MB/s. Compare that with BCM2837 which could do less than 40MB/s over USB. So IO bandwidth is 12.5x, while the processor performance is 3x over BCM2837. It will be a while before its IO performance becomes a similar bottleneck! In other words, the bottleneck has now moved to the processor!

Nevertheless, it would make sense to allocate space on the edge connector for total 2 or 4 lanes to "future-proof" it a bit. On CM4 you can either leave extra lanes unused or put a PCIe expansion switch. A future 271X can provide more than one lane.

I just think a personal cloud or distributed system is an important enough use case that any new CM design should take a systems approach and consider how might one that make it cost efficient and easy to build. Just imagine what CS students can do if they had their own personal distributed system. Or in a home market you don't have to rely on sending all your private data to google/apple/microsoft for voice activated services like siri or image/video recognition. People are already starting to use things like PiHole. The same people would likely want a turnkey secure digital command center.

W. H. Heydt
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Re: Something I'd like to see.

Sun Jul 21, 2019 1:58 am

Gavinmc42 wrote:
Sat Jul 20, 2019 11:45 pm
Mechanical keyboard?
Built like the old IBM buckling springs indestructible keyboards.
In a word: Unicomp. Here: https://www.pckeyboard.com/page/category/UltraClassic The one on my desk is this one (but without the Windows key): https://www.pckeyboard.com/page/product/UNI0P4A

By the way...note the weight.

Heater
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Re: Something I'd like to see.

Sun Jul 21, 2019 6:21 am

That's great. If only I could get one in black and without that space wasting number pad section.

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Gavinmc42
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Re: Something I'd like to see.

Sun Jul 21, 2019 10:55 am

That's great. If only I could get one in black and without that space wasting number pad section.
Don't care about the colour, but those extra number keys must go.

As soon as FreeCAD is working I am going to design a split Colemak ergo.
These Pi4 are so good they need a serious keyboard.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

W. H. Heydt
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Re: Something I'd like to see.

Sun Jul 21, 2019 3:39 pm

Heater wrote:
Sun Jul 21, 2019 6:21 am
That's great. If only I could get one in black and without that space wasting number pad section.
I'd have to check. They might make them in black. As for the numeric keypad..."To each his own," said the old lady as she kissed her cow.

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Imperf3kt
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Re: Something I'd like to see.

Sun Jul 21, 2019 10:27 pm

jamesh wrote:
Sat Jul 20, 2019 3:12 pm
Imperf3kt wrote:
Thu Jul 18, 2019 10:22 pm
A keyboard and mouse take next to no R&D, so it's simply a case of produce sell and profit, but this suggestion is different, it would require research and budget.
Hahahahahahahaha. "Next to no R&D". You have no idea how much pain it took to get those right!!
What research goes into licensing an existing product (that had been refined over decades) and incorporating it into your own?
I don't intend this to be rude, I'm genuinely curious as to how the keyboard came to be and the difficulties you guys has to overcome to bring us the product.

From a consumer perspective, you simply need license an existing design and stuff it inside a plastic shell with a usb hub. Clearly that's not what happened.
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rpdom
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Re: Something I'd like to see.

Mon Jul 22, 2019 7:13 am

Imperf3kt wrote:
Sun Jul 21, 2019 10:27 pm
What research goes into licensing an existing product (that had been refined over decades) and incorporating it into your own?
What colour should it be?
Should it be able to be inserted nasally? (I do not recommend this with a keyboard, fire or wheel).

hippy
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Re: Something I'd like to see.

Mon Jul 22, 2019 11:39 am

Imperf3kt wrote:
Sun Jul 21, 2019 10:27 pm
What research goes into licensing an existing product (that had been refined over decades) and incorporating it into your own?
If one has a hub, keyboard and mouse, it appears it should be an easy job to simply rearrange things to create the integrated product one wants. Makers with dremmels and soldering irons do that all the time.

I would guess R&D wasn't only in electronic design, circuit layout, but in making it a commercial product which would deliver return on investment. That extends from look and feel, optimal keyboard layout, to making things sturdy and robust while embracing 'design for manufacture and assembly' and optimising costs.

And things like getting colour right, the contrast of colours, can take an inordinate amount of time. I imagine there was further debate on how it looks; the smaller "]" and "#" keys, how it works with other language layouts, the cursor key size and layout, what key-cap font should be used, how lettering should be positioned, silk-screened or multi-colour moulded, where the LED's should go, what colour they should be, how bright.

Designing injection moulding tools is an art form in itself, maximising strength against minimising material and getting the weight and balance just right.

https://howchoo.com/media/ow/m5/m2/offi ... led-l.jpeg

It all adds up to a lot more than one might expect.

trejan
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Re: Something I'd like to see.

Mon Jul 22, 2019 4:23 pm

The board inside the official keyboard looks to be custom designed/made by RPi. It has unusual features like the RPi knows what language the keyboard is and there are some dip switches inside for something. It doesn't look like an off the shelf design.

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bensimmo
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Re: Something I'd like to see. ( USB to SATA bridge )

Tue Jul 23, 2019 7:41 am

In case anyone missed the blog overview of the keyboard and mouse.
https://www.raspberrypi.org/blog/offici ... ard-mouse/

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