First post, by Eivind
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Update 2/7/2024: Github page updated with complete KiCad project (schematics, layout, gerbers).
Update 1/4/2024: All boards are shipped. Regrettably, I won't be doing another group-buy, but will be open-sourcing the complete hardware very soon.
Update 12/14/2023: Assembly and shipping is taking longer than expected, but moving along. Meanwhile, basic setup/config guide is up.
Update 11/23/2023: Finally got the boards delivered! Starting the process of completing the assembly, programming and testing everything.
Update 11/14/2023: Assembly is complete, waiting to get the boards shipped to me.
Update 11/7/2023: PCB fabrication is complete, waiting a few more days for SMT/TH assembly to finish.
Update 10/29/2023: The last parts finally arrived at JLC's factory, and the boards are ordered. This means the October group-buy is closed. I'll continue to update this post with the manufacturing progress.
Update 10/23/2023: I made the component orders last week, waiting for all the parts to reach JLC. Because orders are still trickling in, I ordered a bit more than I need - so there are still a few open spots for the group-buy before I order the PCBs themselves.
Update, 10/18/2023: I'm closing the October group-buy in a couple of days, last chance to get in.
Update, 10/9/2023: Added first-page info post and opened October group-buy list.
Since the completion of this project in October 2023, this first post will primarily serve as a presentation of the ITX-Llama mainboard.
The original post has been copied and can be read as the next one in this thread.
The ITX-Llama is my second major project (after the TinyLlama) using the versatile Vortex86EX system-on-module (SOM).
It has a true x86, P6 (Pentium Pro/II/III) compatible CPU running at anywhere between 100-500 MHz, with 16 KB of L1 cache and 128 KB of L2 cache (both of which can be disabled), 128 MB of LPDDR3 RAM and an 8 MB ROM chip.
The CPU speed is roughly comparable to a Pentium 233, or somewhere in that neighborhood, depending on the application/game.
The mainboard has been designed to be as close possible to my dream late-DOS, early Windows 98 system as I could get, given the constraints of the CPU/SOM.
Here are its main features:
- ATX power connector. You can get away with just about the weakest PSU possible, the system doesn't draw much power.
- 3.3V-keyed AGP connector, running at 66 MHz and "1x" speed. AFAIK, most 3.3V and "universal" AGP cards should work fine, albeit at a slower speed than in a true AGP system. The reason for the 1x speed is that the SOM only provides a single PCIe lane, which is fed to a PI7C9X118SL PCIe-to-PCI bridge. AGP will happily run on PCI signals (it's a superset of PCI after all), but without AGP-only features like sideband-addressing.
- 2 USB 2.0 ports
- PS/2 keyboard and mouse connectors
- 2 USB ports that can be used for HID devices (keyboards and mice), that are translated into PS/2 using a dedicated RP2040 chip. Use jumpers to choose between real PS/2 or USB HID for both keyboard and mouse.
- 10/100 Mbit Ethernet RJ45 connector
- RS232 Serial port
- Internal TTL serial port
- Gameport
- Audio ports (line out, line in, microphone in)
- Digital optical audio out port ("Toslink")
- Analog CD audio input connector
- SATA connector
- PC speaker
- Front panel connectors (power switch, reset switch, power LED, HDD LED)
- PC speaker connector
- Power and reset buttons
- Multi-purpose RGB LED for showing power status, HDD activity
- Micro-SD card slot
- "HDD clicker" for SD card activity - for emulating the sound of spinning hard drives
- Built-in Crystal CS4237B-based sound card. Adlib, SB Pro 2, WSS compatible.
- Port for connecting an external real OPL3 module (instead of the CS4237B's built-in one)
- Wavetable connector. There isn't room for the old gigantic ones, but modern boards like the S2 and X2 from Serdashop fit nicely.
- 40-pin connector for attaching a Raspberry Pi running mt32-pi firmware - can be used for both MT-32 or MIDI. Both a male and female header, so you can attach a Pi Zero 2 directly, or run a standard 40-pin cable to a regular Pi.
- Built-in PCM5102 DAC for turning the digital audio from the Pi into analog audio that's routed back into the Crystal chip
- CR2032 real-time clock battery
- ESP8266-based serial-to-Wifi-modem for BBS-ing in DOS, dial-up internet in Windows, etc.
- 3 PWM (4-pin) fan headers, 5V or 12V, selectable by jumpers.
- Custom BIOS, based on Coreboot/SeaBIOS. Tweaked to work with this particular system and has a built-from-scratch settings menu where you can customize various things like CPU speed, disks, audio, network, fans, LEDs, clicker sound, etc.
