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by mahjongg
Wed Feb 26, 2020 11:00 am
Forum: Off topic discussion
Topic: My new ZX81 clone, built from discrete pin-through hole components
Replies: 29
Views: 6924

Re: My new ZX81 clone, built from discrete pin-through hole components

I wasn't satisfied with incomplete wiring to the expansion connector, so I tried to complete the remaining wiring. I did all but two signals, nBUSACK and nWAIT, but I expect to finish those two next week. The layout is now impressively "busy". most wiring is done in 0.15mm, and almost everywhere I h...
by mahjongg
Wed Feb 26, 2020 9:55 am
Forum: Windows 10 for IoT
Topic: Unable to deploy Windows IoT Core on RPI4
Replies: 8
Views: 232

Re: Unable to deploy Windows IoT Core

I shall not ask Microsoft. I shall ask RaspberriPi developers.
Stubborn much?

Good luck with that. :geek:

Its Microsofts responsibility to update their "OS", they seem to not care.
by mahjongg
Sun Feb 23, 2020 8:09 pm
Forum: Troubleshooting
Topic: No WiFi on a 4B-4GB with Raspbian Buster
Replies: 52
Views: 4915

Re: No WiFi on a 4B-4GB with Raspbian Buster

Just set up my pi 4 and fiddled around like a hobo ... :x searching the everknowing interwebs I found a possible solution: Check your screen resolution and make sure that there is no such thing as 1440. maybe lower the frequency as well. Sounds funny, I know. But for me it works and setting the the...
by mahjongg
Sun Feb 23, 2020 7:45 pm
Forum: General discussion
Topic: Raspberry pi 4 loose wire in micro SD card slot
Replies: 6
Views: 237

Re: Raspberry pi 4 loose wire in micro SD card slot

I don't see any "loose wires".

Did you read the boot problem sticky in beginners.

in 99.9% of cases the problem lies with a non bootable sd-card, not with a damaged RPI, all RPI's are tested in the factory and leave the factory working.
by mahjongg
Sun Feb 23, 2020 6:04 pm
Forum: General discussion
Topic: Raspberry PI 4 - USB Boot
Replies: 37
Views: 1610

Re: Raspberry PI 4 - USB Boot

they can do so ALREADY, it just takes an SD-card that is ONLY used for booting from that hard drive or ssd. hence there is no pressure to provide a solution that doesn't require an SD-card. Care to provide a link to simple guide? No problem, it was easy to find this video guide. https://www.youtube...
by mahjongg
Sat Feb 22, 2020 3:58 pm
Forum: Off topic discussion
Topic: Quartz Crystal Occisaltor
Replies: 15
Views: 742

Re: Quartz Crystal Occisaltor

I was curious about a crystal oscillator. I know they could generate a certain frequency, but could a low frequency one blink an led? If a crystal oscillator is in series with a LED, will it blink? Or would there be multiple components being have to be used? Low frequency crystals (as used in real ...
by mahjongg
Sat Feb 22, 2020 3:33 pm
Forum: General discussion
Topic: Raspberry PI 4 - USB Boot
Replies: 37
Views: 1610

Re: Raspberry PI 4 - USB Boot

the question is vavlid as lots of uses require a hard drive or ssd as pi 3 can pi 4 in this pi 4 is not interchanable with pi 3 hence the question thanks you don't get it. lots of uses require a hard drive or ssd, true, but they can do so ALREADY, it just takes an SD-card that is ONLY used for boot...
by mahjongg
Fri Feb 21, 2020 6:28 pm
Forum: General discussion
Topic: Raspberry PI 4 - USB Boot
Replies: 37
Views: 1610

Re: Raspberry PI 4 - USB Boot

Because this "springboard code" has to be able to boot from all kinds of external memory devices (sometimes behind USB-hubs etc) it is a bit more involved than the old RPI3B+ code, so it takes a bit more time to write and test, and before we started with it we decided to first write NETBOOT code. J...
by mahjongg
Fri Feb 21, 2020 4:04 pm
Forum: General discussion
Topic: Raspberry PI 4 - USB Boot
Replies: 37
Views: 1610

Re: Raspberry PI 4 - USB Boot

hippy wrote:
Fri Feb 21, 2020 12:05 pm
A sticky would at least provide a link for members to point to, as the Boot Sticky does, without having to explain further.
You mean "this" post that especially for you I promoted to sticky???
viewtopic.php?f=63&t=265651
by mahjongg
Fri Feb 21, 2020 3:53 pm
Forum: General discussion
Topic: Raspberry PI 4 - USB Boot
Replies: 37
Views: 1610

Re: Raspberry PI 4 - USB Boot

this feature does not appear to be as quite a "niche" request as previously suggested in one of the multiple forums about this. Its much more niche when you realize booting an USB stick can already be done fine . Just add a tiny (1GB) SD-card with first-level boot code that tells the GPU where it c...
by mahjongg
Wed Feb 19, 2020 10:12 am
Forum: Off topic discussion
Topic: My new ZX81 clone, built from discrete pin-through hole components
Replies: 29
Views: 6924

Re: My new ZX81 clone, built from discrete pin-through hole components

Finished routing (100% connectivity). And added enough signals to the expansion port so that I/O based (not memory map based) expansion should work. So printer, PSG, joystick port and any other I/O driven devices should work fine, but memory expansion devices will not. Which should not be problemati...
by mahjongg
Tue Feb 18, 2020 2:11 pm
Forum: Off topic discussion
Topic: Booting linux kernel on RPi3 v1.2 using u-boot
Replies: 2
Views: 3204

Re: Booting linux kernel on RPi3 v1.2 using u-boot

He probably didn't three years ago, and gave up (because its not possible)
Raspberry PI's have a unique boot mechanism, incompatible with u-boot.
by mahjongg
Mon Feb 17, 2020 6:49 pm
Forum: General discussion
Topic: Windows 10 raspberry pi 4
Replies: 4
Views: 403

Re: Windows 10 raspberry pi 4

Normal windows does not run on a RPI, because the RPI doesn't use an Intel/AMD (x86) processor, but instead uses an ARM-CPU, the same CPU that is used in tablets and smartphones. Emulating an Intel/AMD CPU on an ARM is possible, but it will run dozens of times slower than a "real" x86 based CPU of t...
by mahjongg
Mon Feb 17, 2020 12:36 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: MCP3008 with 5v Sensor
Replies: 9
Views: 8544

Re: MCP3008 with 5v Sensor

With an I2C device, the "voltage translation" happen when you make sure the pullup resistors pull the voltage on the two I2C signals up to 3.3Volt. As long as the I2C peripheral is well designed, and accepts ViH signals of 3,3Volt it doesn't matter if the peripheral chip itself is 3V3 or 5V powered....
by mahjongg
Sun Feb 16, 2020 12:44 pm
Forum: General discussion
Topic: GPIO programing
Replies: 9
Views: 349

Re: GPIO programing

added code tags to first post.
by mahjongg
Sat Feb 15, 2020 9:13 pm
Forum: Troubleshooting
Topic: Upside down gpio pins and lcd screen issues
Replies: 6
Views: 117

Re: Upside down gpio pins and lcd screen issues

Mouting headers on the underside instead of the top side will swap all even and uneven pin numbers, so you have to mount the device 180 degrees rotated too, for LCD's that means with the screen mounted toward the RPI, not a useful proposition.
by mahjongg
Sat Feb 15, 2020 9:04 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: MCP3008 with 5v Sensor
Replies: 9
Views: 8544

Re: MCP3008 with 5v Sensor

Generally if you power a device from X volts its outputs will be X volts. Yes, but for the same reason you also cannot input an analog voltage into the ADC that far exceeds the voltage the ADC chip is running off, you will need a resistor divider to lower the analog voltage to a range the ADC can a...
by mahjongg
Sat Feb 15, 2020 2:35 pm
Forum: Advanced users
Topic: RPi 4B Small Laptop Project
Replies: 8
Views: 760

Re: RPi 4B Small Laptop Project

Moved to advanced users, for more attention. Can't delete thread, because at least one other user posted a relevant reply. If you start a duplicate post, flag a moderator (report the post button) If I see it first I will delete this thread as a duplicate. note that private messages are turned off, s...
by mahjongg
Sat Feb 15, 2020 2:22 pm
Forum: Off topic discussion
Topic: PoE Hat Troubleshooting
Replies: 5
Views: 522

Re: PoE Hat Troubleshooting

Not a RPI product, so please take your complaint to the producer. Tip: when a monitor is not plugged into a grounded socket the filtercaps in the mains inlet will put a leakckage voltage of half mains voltage on the ground wire of the HDMI cable., and so on the whole PI. This voltage (US 55 Voltmost...
by mahjongg
Fri Feb 14, 2020 11:50 pm
Forum: General discussion
Topic: Supported programming languages on RPi
Replies: 12
Views: 588

Re: Supported programming languages on RPi

In a recent post, far away in another thread, I was reprimanded for speculating that we are being inundated with posts by some kind experimental AI/deep learning/machine learning/SPAM bot. The warnings to me are: 1) A new users fist post. 2) A really weird question. Posed in a weird way. Weird enou...
by mahjongg
Wed Feb 12, 2020 12:37 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: MCP3008 with 5v Sensor
Replies: 9
Views: 8544

Re: MCP3008 with 5v Sensor

The MCP3008 uses an SPI interface, so the SPI levels should be 3V3, meaning the chip should run on 3.3V, so as to not to output 5V SPI signal levels to the RPI (as this would blow up the RPI, "the RPI is NOT 5V compatible"). to input 5V analog signals to this MPC3008 ADC you need a resistor divider ...
by mahjongg
Wed Feb 12, 2020 12:06 am
Forum: Off topic discussion
Topic: My new ZX81 clone, built from discrete pin-through hole components
Replies: 29
Views: 6924

Re: My new ZX81 clone, built from discrete pin-through hole components

Current status (February 12, 2020)
temporarily removed much of the expansion connector wiring, for a better overview.
Image

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