Editing AMD Geode/Video 1/Script
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This is a textual description of the video. | This is a textual description of the video. | ||
TODO: Clean up | |||
== Introduction == | == Introduction == | ||
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Voice: "Ideally I'd use a period accurate IBM PC" | Voice: "Ideally I'd use a period accurate IBM PC" | ||
A screenshot of expensive eBay listings scrolls past. One is shown to cost $500 AUD. | |||
Voice: "But these are really expensive" | Voice: "But these are really expensive" | ||
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The monitor is shown again with the text "No Signal" displayed. | The monitor is shown again with the text "No Signal" displayed. | ||
The board is shown with a chip marked | The board is shown with a chip marked 'V1.18' removed from its socket. | ||
Voice: "I removed the BIOS chip to see if it would still beep. It didn't." | Voice: "I removed the BIOS chip to see if it would still beep. It didn't." | ||
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Voice: "Next I looked at the clock battery." | Voice: "Next I looked at the clock battery." | ||
A multimeter is shown with its probes touching the positive and negative sides of the battery. It displays the value | A multimeter is shown with its probes touching the positive and negative sides of the battery. It displays the value 198mV. | ||
Voice: "My multimeter showed it was around | Voice: "My multimeter showed it was around 200mV. Completely dead." | ||
A close up of the battery being held by pliers is shown. The brand name RAYOVAC and the text "LITHIUM 3V BR1632 USA" is engraved on the chip. | A close up of the battery being held by pliers is shown. The brand name RAYOVAC and the text "LITHIUM 3V BR1632 USA" is engraved on the chip. | ||
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Voice: "Perhaps a dead battery corrupted the BIOS settings somehow?" | Voice: "Perhaps a dead battery corrupted the BIOS settings somehow?" | ||
The second monitor is shown again, this time with an orange plastic frog glowing on the desk near it. The monitor still says "Input Not Support" | The second monitor is shown again, this time with an orange plastic frog glowing on the desk near it. The monitor still says "Input Not Support" | ||
Voice: "Running without the battery didn't help." | Voice: "Running without the battery didn't help." | ||
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A breadboard is shown with jumper wires connected to various ports on the DB9 serial port. | A breadboard is shown with jumper wires connected to various ports on the DB9 serial port. | ||
Voice: "I made a null modem cable on my breadboard | Voice: "I made a null modem cable on my breadboard using jumper wires." | ||
An oscilloscope probe goes in to one of the breadboard holes. | An oscilloscope probe goes in to one of the breadboard holes. | ||
The oscilloscope screen shows a signal at | The oscilloscope screen shows a signal at 0v raising to 5v briefly then dropping down to -5v. | ||
Voice: "Probing it showed the | Voice: "Probing it showed that the transmit line was being held properly. But it wasn't outputting any bytes." | ||
Broken off jumper wire connectors are shown stuck attacked to the serial port. The wires they belong to are shown with their copper strands exposed at the end. Pliers come in to frame and pull them out. | Broken off jumper wire connectors are shown stuck attacked to the serial port. The wires they belong to are shown with their copper strands exposed at the end. Pliers come in to frame and pull them out. | ||
Voice: "I | Voice: "I also broke a few breadboard wires in the process. That sucks." | ||
== VGA probing == | == VGA probing == | ||
An oscilloscope probe is shown entering a hole on the VGA connector. | An oscilloscope probe is shown entering a hole on the VGA connector. | ||
Voice: " | Voice: "Okay time to check the VGA signals." | ||
An oscilloscope screen shows a | An oscilloscope screen shows a 0v signal with shorts jump between 6.80v and -2.56v. | ||
Voice: " | Voice: "First up is vertical sync. This signal pulses once every frame." | ||
The camera zooms in to show the frequency of the signal is 60. | The camera zooms in to show the frequency of the signal is 60.00Hz and the period is 16.67ms. | ||
Voice: " | Voice: "In this case it's 60hz." | ||
The oscilloscope shows a a | The oscilloscope shows a a 5V wide square wave with cursors measuring the wave. The wave is around 5v, peaking at 5.57v on the leading edge and dropping down to some unknown voltage on the trailing edge. The time a pulse of the wave takes is 40 microseconds, or 24.75KHz. | ||
Voice: " | Voice: "Zooming in to a single pulse we can see that's a 5v square wave lasting for around 40 microseconds." | ||
The oscilloscope shows the leading edge of the square wave. It peaks at 6. | The oscilloscope shows the leading edge of the square wave. It peaks at 6.64v and takes 228ns to settle to 4.64v. | ||
Voice: "The pulse seems to peak around 6. | Voice: "The pulse seems to peak around 6.6v and takes around 230 nanoseconds to settle. This all look fine to me." | ||
An oscilloscope probe is shown entering another hole on the VGA connector. | An oscilloscope probe is shown entering another hole on the VGA connector. | ||
Voice: "Next | Voice: "Next horizontal sync." | ||
The oscilloscope shows a | The oscilloscope shows a 0v signal with longer jumps between 6.64v and -2.40v. The camera zooms in to show frequency is 75.02KHz and the period is 13.33 microseconds. | ||
Voice: " | Voice: "The signal pulses every row of pixels and this looks to be around 75KHz." | ||
The oscilloscope shows a | The oscilloscope shows a 5V wide square wave with cursors measuring the wave. The wave peaks at 6.55v at the leading edge and -2.41v on the trailing edge. The time a pulse takes is 1.45 microseconds, or 692.0KHz. | ||
Voice: " | Voice: "Zooming in the pulse is the same voltage as the vertical sync and it lasts around 1.45 microseconds." | ||
The oscilloscope shows the leading edge of the square wave. It peaks at 6. | The oscilloscope shows the leading edge of the square wave. It peaks at 6.60v and takes 197ns to settle to 4.86v. | ||
Voice: "The pulse takes 197 nanoseconds to settle high" | Voice: "The pulse takes 197 nanoseconds to settle high" | ||
The oscilloscope shows the trailing edge of the square wave. It drops to -2. | The oscilloscope shows the trailing edge of the square wave. It drops to -2.51v and takes 307ns to settle to -51.20mV. | ||
Voice: "and 307 nanoseconds to settle low. This looks | Voice: "and 307 nanoseconds to settle low. This looks fine to me too." | ||
An oscilloscope probe is shown entering another hole on the VGA connector. | An oscilloscope probe is shown entering another hole on the VGA connector. | ||
Voice: " | Voice: "Next up: Red signal" | ||
The oscilloscope shows a flat line with a max voltage of | The oscilloscope shows a flat line with a max voltage of 280mV and minimum of -360mV. | ||
Voice: " | Voice: "Uh-oh. Nothing" | ||
The camera zooms to show a max voltage of | The camera zooms to show a max voltage of 200mV and minimum of -120mV. | ||
Voice: "It just stays around 200 millivolts." | Voice: "It just stays around 200 millivolts." | ||
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Voice: "Okay, green" | Voice: "Okay, green" | ||
The oscilloscope shows a flat line with a max voltage of | The oscilloscope shows a flat line with a max voltage of 160mV and minimum of -80mV. | ||
Voice: "Same thing but | Voice: "Same thing but around 160 millivolts." | ||
An oscilloscope probe is shown entering another hole on the VGA connector. | An oscilloscope probe is shown entering another hole on the VGA connector. | ||
Voice: " | Voice: "Okay, blue?" | ||
The oscilloscope shows a flat line with a max voltage of | The oscilloscope shows a flat line with a max voltage of 280mV and minimum of -160mV. | ||
Voice: " | Voice: "Same thing as green, what? These should all be much higher." | ||
The underside of a PCB is shown with the VGA connector's solder joints visible. | The underside of a PCB is shown with the VGA connector's solder joints visible. | ||
Voice: "Just to be sure | Voice: "Just to be sure I took a look at the VGA section of the board." | ||
The top of the PCB is shown with a probe pointing at an area containing various tiny components next to the connector. | The top of the PCB is shown with a probe pointing at an area containing various tiny components next to the connector. | ||
Voice: " | Voice: "But it didn't show any visible issues." | ||
== SD card adapter == | == SD card adapter == | ||
An IDE to SD card adapter is shown on the table, with an SD card inserted. Its circuit board is black and yellow and the main chip on the board has a | An IDE to SD card adapter is shown on the table, with an SD card inserted. Its circuit board is black and yellow and the main chip on the board has a 'QC Passed' sticker that changes color based on the angle. | ||
Voice: "I | Voice: "I tried to attach an IDE to SD card adapter and boot from it." | ||
A single Molex to two Molex cable is shown with the power supply's wires attached to the single connector. | A single Molex to two Molex cable is shown with the power supply's wires attached to the single connector. | ||
Voice: "I managed to power it using a Molex splitter." | Voice: "I managed to power it using a Molex splitter." | ||
The board computer and SD card adapter are shown next to each, each with LEDs on indicating power. | |||
One end of a green and blue IDE cable is shown next to the IDE port on the board. The IDE cable is slightly larger than the port on the board. A hand tries to plug it in without success. | One end of a green and blue IDE cable is shown next to the IDE port on the board. The IDE cable is slightly larger than the port on the board. A hand tries to plug it in without success. | ||
Voice: "But the IDE connector on the board was too small | Voice: "But unfortunately the IDE connector on the board was too small." | ||
== Molex USB adapter == | == Molex USB adapter == | ||
An eBay page showing a cable with a Molex end and a USB end is visible. The item is listed as | An eBay page showing a cable with a Molex end and a USB end is visible. The item is listed as '5V USB Power to 4Pin Molex(2Pin Wired) Cable 50cm'. The price is listed as $8.59 AUD. The image has arrows pointing to the USB and Molex end, subtitled 'USB Power 5V' and 'Molex(2Pin wired) 5V' respectively. | ||
Voice: "As an aside I bought a USB to Molex adapter for powering the board." | Voice: "As an aside I bought a USB to Molex adapter for powering the board." | ||
The adapter plugged in to the Molex splitter is shown. A screwdriver gestures at how when connected the | The adapter plugged in to the Molex splitter is shown. A screwdriver gestures at how when connected the 5V red wire of the adapter is connected to the 12V yellow wire of the splitter, instead of the 5V red wire on the splitter. | ||
Voice: " | Voice: "Unfortunately it had the 5V pins connected to the 12V Molex rail." | ||
A hand is shown holding the adapter and pushing one of the female metal contacts out of the adapter by sliding the screwdriver between the plastic of the adapter and the metal contact. The hand then pulls the contact out from the back of the connector. | A hand is shown holding the adapter and pushing one of the female metal contacts out of the adapter by sliding the screwdriver between the plastic of the adapter and the metal contact. The hand then pulls the contact out from the back of the connector. | ||
Voice: " | Voice: "Fixing it is quite easy though. Step one: Use a screwdriver to unlock the pins and pull them out through the back." | ||
A hand holds the removed female contact and uses a screwdriver to bend back out the small locking hooks that were pushed in by the previous removal step. | A hand holds the removed female contact and uses a screwdriver to bend back out the small locking hooks that were pushed in by the previous removal step. | ||
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A hand hold the end and the end of some pliers is being forced in to the female contact. | A hand hold the end and the end of some pliers is being forced in to the female contact. | ||
Voice: "Step three: Use | Voice: "Step three: Use pliers to make the pin round again." | ||
A hand is holding the adapter while a screwdriver pushes the contact back in to the adapter in a different hole. | A hand is holding the adapter while a screwdriver pushes the contact back in to the adapter in a different hole. | ||
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Voice: "Step five: Check that it looks good." | Voice: "Step five: Check that it looks good." | ||
A hand plugs the adapter in to the single-board computer and the USB end in to a USB power supply. It has a screen showing the current voltage of the port which is | A hand plugs the adapter in to the single-board computer and the USB end in to a USB power supply. It has a screen showing the current voltage of the port which is 5v, but quickly switches to 1A when the board powers on. | ||
Voice: "I | Voice: "As a test I plugged the cable in to the board and a USB supply. It booted up just fine from what I saw." | ||
A hand holds the adapter which is still plugged in to the supply. Pliers are inserted in to the pins on the adapter. The screen on the power supply is blank. Removing the pliers causes the screen to turn back on. The pliers are re-inserted which turns off the screen. | A hand holds the adapter which is still plugged in to the supply. Pliers are inserted in to the pins on the adapter. The screen on the power supply is blank. Removing the pliers causes the screen to turn back on. The pliers are re-inserted which turns off the screen. | ||
Voice: " | Voice: "By the way make sure to use a decent USB power supply, something that can handle short circuits without exploding is a good start." | ||
== USB power meter == | == USB power meter == | ||
The power supply is shown upside down. A USB power meter is inserted with the adapter cable connected to it. The meter shows the voltage | The power supply is shown upside down. A USB power meter is inserted with the adapter cable connected to it. The meter shows the voltage 4.97V and amperage around 1.1A. | ||
Voice: "Just for fun I plugged the board in to a USB power meter." | Voice: "Just for fun I plugged the board in to a USB power meter." | ||
The meter shows a graph of the current consumption. The graph starts at 0. | The meter shows a graph of the current consumption. The graph starts at 0.9A and fluctuates between 1A and 1.4A before settling down to 1A. | ||
Voice: "It verified the system hangs around | Voice: "It verified the system hangs around 1A with 1.5A peaks." | ||
== Reading manuals == | == Reading manuals == | ||
A manual is shown titled "PCM-9375 3.5" SBC w/AMD LX800, VGA, LCD, LAN, USB2.0 and SSD User Manual" | A manual is shown titled "PCM-9375 3.5" SBC w/AMD LX800, VGA, LCD, LAN, USB2.0 and SSD User Manual" | ||
Voice: "Without | Voice: "Without obvious hardware faults it was timed to look at the user manual." | ||
A page is shown mentioning section 2.1.5 TV "enable (J5)" with a table showing that you can enable or disable the TV setting with a jumper, but by default it is enabled. | A page is shown mentioning section 2.1.5 TV "enable (J5)" with a table showing that you can enable or disable the TV setting with a jumper, but by default it is enabled. | ||
Voice: "It mentions a TV enable jumper, but | Voice: "It mentions a TV enable jumper, but all that did was stop the machine booting." | ||
A page with section 4.4.1 "Display type" is shown, explaining that the board can be configured as a CRT, flat panel, or both. Dual display is default. Changing the setting requires entering the BIOS or contacting Advantech's technical support center. | A page with section 4.4.1 "Display type" is shown, explaining that the board can be configured as a CRT, flat panel, or both. Dual display is default. Changing the setting requires entering the BIOS or contacting Advantech's technical support center. | ||
Voice: "The VGA section says I need to use the BIOS to configure the | Voice: "The VGA section says I need to use the BIOS to configure the display." | ||
A page with default BIOS settings is shown, with the "Output Display" option defaulting to "CRT". | A page with default BIOS settings is shown, with the "Output Display" option defaulting to "CRT". | ||
Voice: "The BIOS section says it's configured to use the VGA | Voice: "The BIOS section says that it's configured to use the VGA connector by default." | ||
A page with a table for connecting wires between a Sharp LQ121S1DG31 LCD and PCM-9375 board to get LCD output is shown. | A page with a table for connecting wires between a Sharp LQ121S1DG31 LCD and PCM-9375 board to get LCD output is shown. | ||
Voice: "The LCD section | Voice: "The LCD section says I should connect a Sharp display, but that's about it." | ||
A manual is shown titled "AMD Geode LX Processors Data Book". | A manual is shown titled "AMD Geode LX Processors Data Book". | ||
Voice: " | Voice: "Okay let's look at the Geode data book." | ||
A page of the manual shows a complex block diagram explaining how the video processor module works, with arrows exiting the module and pointing to an 'output devices' block with the elements "VIP, TV Encoder, CRT DAC (3x8 bit), TFT Panel, AMD Geode Companion Device" listed in it. | A page of the manual shows a complex block diagram explaining how the video processor module works, with arrows exiting the module and pointing to an 'output devices' block with the elements "VIP, TV Encoder, CRT DAC (3x8 bit), TFT Panel, AMD Geode Companion Device" listed in it. | ||
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A page shows a table of signals and their types, including HSYNC, VSYNC, DVREF, DRSET, DAVdd, DAVss, RED, GREEN. | A page shows a table of signals and their types, including HSYNC, VSYNC, DVREF, DRSET, DAVdd, DAVss, RED, GREEN. | ||
Voice: "The DAC needs a 1.235 | Voice: "The DAC needs a 1.235 voltage reference and a 1.21K current setting resistor." | ||
A page shows a download page of the file XO-1-Schematics.pdf with the description "Schematics for the C2 version of the XO-1 Laptop". | A page shows a download page of the file XO-1-Schematics.pdf with the description "Schematics for the C2 version of the XO-1 Laptop". | ||
Voice: "I looked up | Voice: "I looked up a schematic for another Geode board. I found the One Laptop Per Child XO-1." | ||
A screenshot of schematics relating to the DVREF, DRSET and DAVdd and DAVss pins is displayed. In order to generate 1. | A screenshot of schematics relating to the DVREF, DRSET and DAVdd and DAVss pins is displayed. In order to generate 1.235V a resistor divider is used based on the 3.3v rail, with various bypass capacitors smoothing out the 3.3v rail and feeding it to the DAV pins. The DRSET pin has a 1.21K resistor connected between it and ground. | ||
Voice: " | Voice: "After staring at it for a while I figured if anything was going to break it would be the voltage divider used for VREF." | ||
== Finding | == Finding VREF == | ||
Various shots of multimeter probes touching ends of resistors on the board are shown. | Various shots of multimeter probes touching ends of resistors on the board are shown. | ||
Voice: "I | Voice: "I spent a few days searching for the resistor divider. On a board of resistors. With values that might not be the correct value." | ||
Tweezers pull back a sticker containing the MAC address of an Ethernet chip. Underneath is the Realtek logo that looks like a crab. | Tweezers pull back a sticker containing the MAC address of an Ethernet chip. Underneath is the Realtek logo that looks like a crab. | ||
Voice: "I even checked the Realtek crab logo." | Voice: "I even checked in the Realtek crab logo." | ||
Some components near the board are shown, including resistors and a shunt. A multimeter probe touches the shunt. | Some components near the board are shown, including resistors and a shunt. A multimeter probe touches the shunt. | ||
Voice: "Eventually I didn't find | Voice: "Eventually I didn't find a resistor divider but I found a zener diode. It had the correct voltage and everything." | ||
A diagram showing how the components fit together is shown. | A diagram showing how the components fit together is shown. DVSS which is 3.3v connects to the 1.22v regulator. From the 1.22v regulator a 0.25nF cap and 10k resistor in parallel run to DVREF. The 1.21k resistor follows from the DVREF capacitor and resistor to the DRSET pin. | ||
Voice: " | Voice: "Here's a badly drawn diagram showing the shunt and the other DAC resistors." | ||
== Probing BGA signals == | == Probing BGA signals == | ||
TODO | |||
== Booting Linux == | == Booting Linux == | ||
TODO | |||
= Probing VGA again = | |||
TODO | |||
= Soldering disaster = | |||
TODO | |||
== Outro == | == Outro == | ||
TODO | |||