Raspberry Pi 4

Ah – constant humour!

One tries (or is that “is rather trying”?}
The 3.141 clocked Pi would of course be the start of a song lyric: "Pi, Pi baby Pi

Which is Really Irrational.Pi." :)

Bye, Bye, Miss Irrational Pi,
Drove my…

Someone else can finish this one. It’s too hard for me. At this time of the day.

I wonder if there will ever be a Pi clocked (by default) at 3.141GH (3.142 if the rounding helps)

A NetBurst one?

I finally got my pi4 and thanks to everyone’s help the card I made up yesterday worked first time. I’m writing this in netsurf on a pc using vnc to the pi4. So far it appears to be working fine.

To summarize how I’m connecting it up it.

Power via GPIO pins from a bench power supply
monitor lead
USB3 powered hub plugged into the USB C port using a type-A type-C adapter
USB2 lan adapter for networking
keyboard and mouse.

The pi needs a powered hub to be used like this. Using the hub unpowered causes the voltage on the hub to drop below 4 volts (measured with a USB voltmeter) which causes numerous problems like the pointer sticking.

Even with a powered hub I’ve noticed that the voltage measured at the pi’s own usb port is 25mA less than the voltage at the power supply which I would have thought is a bit low maybe powering from the usb c port is different. I also note that the max current I’ve seen drawn while using a powered hub is 800mA

Instead it is all git nonsense.

It should just be a case of cloning the repository, although ROOL do seem to have structured things interestingly.

Incidentally, once you start using Git, you quickly find out why it’s near ubiquitous now: it’s very good at doing what it does. Given a decent front end, it “just works” and automagically sorts out the kinds of things that Subversion would go into a serious sulk over. There’s a learning curve, but having used it for work for the past twelve months, once over the hill, it does make things much easier than SVN ever did…

Ok got rom built just waiting for the pi4,case,usb3 adaptor to come next week

Can anyone confirm if RISC OS programs (especially games and demos featuring horizontal scrolling) running on the Raspberry Pi 4 suffer from the tearing/VSync issue discussed in this post on the official Raspberry Pi forum, and elsewhere:

https://www.raspberrypi.org/forums/viewtopic.php?t=246291

A Google search e.g. “raspberry pi 4 tearing” shows this problem being discussed on several other forums.

Can anyone confirm if RISC OS programs (especially games and demos featuring horizontal scrolling) running on the Raspberry Pi 4 suffer from the tearing/VSync issue

I don’t have a Pi4 to test, however…

It looks like a caching and/or clocking issue with the PixelValve, I’ll be impressed if they manage to fix that in software.

It would be an issue for anything that isn’t triple buffering, due to the way the framebuffer is always a frame behind…on earlier Pi’s you have to update the display buffer to update the backbuffer. Any self-respecting game dev would use triple buffering for anything targeted at a Pi, to ensure no matter what machine it runs on, it’s updating a backbuffer.

Provided the issue doesn’t affect a fully cache cleaned display buffer, I would expect a Pi4 to handle games okay. The real test would be something like Pac-mania under ADFFS, which shows up any flaws in clocking due to its 50Hz frame-rate and scrolling.

Perhaps someone with a Pi4 could see if ADFFS runs and test this? I’ll order a Pi4 and do more thorough testing at some point.

Anyone know if there is there any publically available documentation for the Pi4. On the on hand the XHCI spec is 600+ pages long – nice – and on the other I can’t see anything for the BCM2711 SOC, BCM54213PE lan or VL805-Q6 usb

Perhaps someone with a Pi4 could see if ADFFS runs and test this? I’ll order a Pi4 and do more thorough testing at some point.

I just tested running Pacmania on ADFFS from PackMan on a Pi 4. My eyes couldn’t detect any differences to running the same on a Pi 3B.

Managed to “compact” my Pi4 system down to a tidier setup…

I just tested running Pacmania on ADFFS from PackMan on a Pi 4. My eyes couldn’t detect any differences to running the same on a Pi 3B.

Thank you Chris, that answers David’s query and saves me buying a Pi4 before there’s an official OS build available for download.

Another option to power the Pi4 via GPIO is to use a Picade hat available here.

I ended up powering it from a charging port on the USB3 hub I’m using. I had a microusb breakout board so could use a type-a microusb cable.

Is the clock speed supposed to drop when idling? Temps seem to be a constant 60 which is higher than the 50 that raspian idles at (no cooling)

I am now using a Pimoroni Wide Input SHIM with a variable output Maplin plug top PSU that I already had.

Is the clock speed supposed to drop when idling?

Yes. Mine idles at 600MHz as expected. There is no cooling, no over-clocking and no case. It is idling at about 50°C.

Mine idles at 600MHz as expected

So it does. I’d had a problem with the cpuclock frontend crashing (fixed now -thanks Chris Johnson) so was trying to read the temps from a taskwindow but that obviously just speeds up the clock.

Mine seems to be running at about 37 degrees above ambient at 1500 and 27 above ambient at 600.

So a nice cool 53 at 1500 at the moment brrr…

Hi, I’ve been trying to get my Pi4 to run RISC OS using a UART for
keyboard and the ‘DebugTerminal’ option in the kernel but I cannot
get input to the Pi4 to work properly. The DebugTX output reporting
module initialisation appears fine on the host terminal (minicom
on Ubuntu or !SerialTerminal on WandBoard) but whatever I type
produces garbled (mostly top-bit set) characters on the Pi4’s
screen, yet oddly some of the characters seem to echo okay via
the WrchV output back to the host terminal.

I’ve tried both with MiniUART true and with it false, and varied
terminal settings experimentally but I believe the settings should
be 115200 8N1 no handshaking. That works for Pi4 to host, just
seemingly not in the other direction. When trying to use the MiniUART
I have set enable_uart=1/core_freq=250 but seemingly to no effect.

Can anyone help please? I must be missing something since I’m aware
people have used UART for input prior to the USB bringup. I can
build ROMs but I don’t have suitable USB-C hardware at present so
I’d rather use the Serial hat (modmypi.com) for now, if possible.
Thanks.

Did you edit BuildSys.Components.ROOL.BCM2835 to remove/disable the DualSerial module? You need to do that otherwise the OS will also be trying to use it as a regular serial port, causing a bunch of the settings to be reset to the OS_SerialOp defaults.

Aha, that’s got serial input working for the regular (non-mini) UART. Great, thank you!

Update to Aemulor including Pi4 build at the usual location. The other builds have only minor UI tweaks; I just prefer to keep all builds in step. Let me know if you find any issues with the Pi 4 build in particular please; moving test apps/files to mine is arduous currently.

In creating that, I’ve resurrected the SerialKeyMouse host application for Windows 10/Visual Studio 2017 and intend to make available a tidied-up build (it really was a very quick hack all those years ago) for Windows and an equivalent app for RISC OS hosts.

I have uploaded Update12 which contains the !Boot.Loader directory and firmware to upgrade the firmware on a Raspberry Pi model 1,2,3, A, A+, B and B+ etc. to RISC OS 5.26 (18-Oct-2018), and to provide a RISC OS 5.27 rom suitable for the Pi4 see here.

The usual caveats apply when copying a !Boot image onto your existing boot setup. Check the filer options are set to Verbose and Force and that Newer is not ticked. Keep a backup copy of your existing boot but do not copy the file Loader, instead create a directory in your backup called ‘Loader’ and copy the contents of Loader not the file itself.

The firmware will be updated to October 2018/February 2020 and the config.txt file will be amended to load different roms depending whether the machine concerned is a model 4 or not. In other words a single SD card image will work on any model of Pi. On a Pi 4 you will need to add a USB3 OTG hub on the power input socket (for keyboard, mouse and pen drives etc.) and supply power via the header. Add an Elesar WiFi Hat for WiFi. A suitable USB to Ethernet adapter connected to the hub might also work (untested).

Thanks Chris. I’ll test it with my USB Type-C dock.

On a Pi 4 you will need to add a USB3 OTG hub on the power input socket (for keyboard, mouse and pen drives etc.) and supply power via the header

I have used an ACE4U hub to get my Pi4 up and running. That way, you can power the ACE4U with a standard micro USB PSU, and use a microUSB → USB-C cable to connect the hub to the USB-C port on the Pi which both powers it and allows data through. No need to power via the GPIO at all.

Add an Elesar WiFi Hat for WiFi. A suitable USB to Ethernet adapter connected to the hub might also work (untested).

I’ve tried the USB to ethernet adaptor that comes with the ARMbook and it works using the method above.

All works without the yellow flash too!

All works without the yellow flash too!

My Pi 4 hasn’t displayed the yellow flash symbol, even though I’ve had power issues. (Portable mouse, natural keyboard and SSD, plus adapter)

What I concluded is that the new Pi needs the official power supply (or something to match it) and I’d recommend using a powered hub. Adding these two things solved some odd issues – Linux.

I had some power issues with a dodgy PSU, which kept bringing up a blank screen after random amounts of time, very similar to the Shutting down-ish thread about the Pi3 and I thought it had re-arisen. But the yellow flash was present. Luckily, swapping to a (clearly not quite) identical PSU resolved everything.