AMD Geode/Video 1/Script
This is a textual description of the video.
Introduction
My DOS Programming playlist on YouTube scrolls down the screen.
Voice: "I've been writing a DOS program for a while now"
The DOSBox-X home page scrolls down the screen.
Voice: "I've been using DOSBox but it would be nice to use real hardware"
A picture of an IBM PC XT taken by Ruben de Rijcke is shown on the screen with big green "IBM" text on it.
Voice: "Ideally I'd use an actual 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"
An eBay listing titled "Vintage Advantech PCM-9375 REV. A1 SBC Single Board Computer - AMD Geode LX800" is shown. Its status is marked as "For parts or not working, sold as-is with no guarantees." It's listed as $50 AUD.
Voice: "Checking eBay I found and industrial single-board computer for $50"
The listing description is shown. It clarifies: "For sale here is an Advantech PCM-9375 REV. A1 single board computer. Previously, I was able to boot Windows 98SE from a Compact Flash card and everything worked fine. It currently refuses to output a video signal that any of my monitors can recognise, so it's being sold as-is for parts with no guarantees. For a full spec sheet, see Advantech's site."
Voice: "The low price is just due to it's video output being broken. Most computers are designed to be useless without video output so naturally this is seen as garbage."
A receipt showing payment for the board is shown. It cost $50 AUD with free shipping. It was paid on 7 November 2021 and delivered on 12 November 21.
Voice: "I bought it anyway."
A hand is shown placing the board on a table. It is an unprotected circuit board with its chips, connectors and pin headers exposed. One large heatsink covers the CPU and another smaller heatsink covers the companion chip.
Voice: "So here it is: The PCM 9375. It stars a Geode LX800 CPU and CS5536 companion chip."
A small stick of RAM is shown.
Voice: "512 megabytes of DDR1 RAM."
An empty CompactFlash connector is shown.
Voice: "CompactFlash for storage."
The side of the board is shown with four ports: A DB9 serial port, an Ethernet port, a PS/2 keyboard port and a VGA port.
Voice: "A serial port, an Ethernet port, a PS/2 port, VGA port"
A daughterboard connected to the main board is shown, with an Ethernet port on it as well as a mini USB connector. The board is unplugged already, and pliers are used to remove it entirely.
Voice: "As well as a mini USB port and a second Ethernet port. We're just going to remove those for now while we troubleshoot."
Initial powering
A power supply with growing green LEDs flicker showing 0 volts and the word "off". Connected to it are two long bunched up wires that clip in to two pins on the board.
Voice: "The first thing I did was hook it up to a current limited power supply."
A hand is shown turning the power supply on. The camera zooms closer and shows the text jumping on the display changing to 5 volts 1 amps. The amperage jumps between 0.9 amps and 1.1 amps.
Voice: "It pulled a stable load so it wasn't completely dead on arrival."
A small lapel microphone is shown next to the board's corner. A single short beep is heard.
Voice: "It beeped. That's probably good."
A hand is shown plugging a VGA cable in to the board.
Voice: "Let's plug in a monitor and check things out then huh"
A computer monitor is shown. Grey text appears in a box with the text "Input Not Supported" slowly moving diagonally down the screen.
Voice: "And... Input not supported."
An oscilloscope probe is shown being attached to the power wire clip followed by a rapid zoom in to an oscilloscope's view.
Voice: "So I scoped the power rail."
The oscilloscope draws a flat line at 0 volts that suddenly jumps up to 5 volts and continues at 5 volts for 15 seconds.
Voice: "A major voltage drop can signal the machine isn't booting properly. I don't see that here"
The oscilloscope draws a thin line from the bottom of the screen up to 5 volts then thickens it showing around 20 millivolts of noise.
Voice: "On the other hand no drop at all could signal the machine is dead. I don't see that here either."
The camera pans to the power supply displaying 5 volts and a steady around 1.065 amps.
Voice: "Everything looks fine power wise."
RAM testing
A hand pulls out a stick of RAM and places another in.
Voice: "Bad memory can cause some weird issues so I tried another stick of RAM."
A different monitor is shown with the text "Input Not Support" appearing after a second of being blank.
Voice: "Same result. Input not support."
A hand is shown removing the RAM stick without placing another in.
Voice: "Just to confirm the RAM was actually doing something I removed it-"
The video cuts to the microphone pointed at the buzzer again.
Voice: "-and found the BIOS gave some long beeps."
A set of long beeps can be heard.
The monitor is shown again with the text "No Signal" displayed.
The board is shown with a chip marked 'V1.18' removed from its socket.
Voice: "Just to confirm this is the BIOS beeping I removed the BIOS. Everything was silent."