MIST.1010

10x10cm PCB variant of MIST FPGA project

[More photos]

Tech specs:

• EP3C25E144 FPGA
• 32/64Mb SDRAM
• VGA/RGB video output
• Composite video + audio output via 3.5 jack connector (raspberry-pi compatible pinout)
• 4xUSB ports for keyboard, mouse and joysticks
• 2xDB-9 ports for Amiga mouse and joysticks
• SD/microSD card slot
• RTC (clock) with battery
• Tape input / output
• ESP8266 WiFi module
• MIDI input and output (starting from rev.C)
• Type C (starting from rev.D) or MicroUSB power supply
• Board optimized for G738 and G706 cases

Some random photos: link

Changelog

• Rev.A - first revision. Please note the errata.
• Rev.A1:
  • fixed all rev.A issues
  • LM3940IS-3.3 replaced to NCP1117-3.3
  • sound output circuit has been replaced with the original one from the MIST 1.3 circuit
  • C39, C40, C80 tantalum capacitors has been replaced by aluminum electrolytic capacitors
  • added ARM's "erase" testpoint
  • removed useless internal speaker
• Rev.A2:
  • C41, C68, C69 10uf ceramic capacitors has been replaced with 22uf tantalum
  • added C74 ceramic capacitor near ESP-01 module
• Rev.B:
  • added ESP-12E/F footprint (ESP-01 is still an option)
  • added MIDI input and output
  • removed U11 - AD724 encoder
  • added resistors-based CVBS (Y+C) video circuit
  • added JP4 solder jumper to disconnect CVBS circuit from 3.5mm jack
  • added U16 buffer with dedicated power source U17 for audio 1-bit DAC
  • added USB 2.54mm header
  • tuned SDRAM traces length for better match with MIST v1.3 PCB
  • changed U6 (attiny) footprint from DIP to SOIC
  • changed Y1 and Y2 footprints from THT to SMD
  • changed 1117-3.3 footprint from TO-252-2 to SOT-223-3
  • added U12 dedicated +3.3V power source for SD card and WiFi
  • 3mm front leds replaced by 5mm
  • R38 (VGA's +5V 0Ω resistor) has been replaced by solder jumper
  • changed tape header pinout
  • pcb corners are rounded now
  • experimental reset circuit based on MAX809
  • various changes in board layout
• Rev.C:
  • used USB Type C instead of Micro USB
  • PJ-320 3.5mm jack replaced by PJ-322
  • added solder jumper to select 3.5mm jack CVBS pinout
  • improved power distribution for FPGA chip
  • removed U16 buffer for DAC as it didn't bring any benefits
  • marked C27 and C28 as DNP
  • reverted to old reset circuit
  • various minor changes in board layout
• Rev.C1:
  • changed R47 from 220Ω to 1kΩ to reduce power led brightness
  • slightly moved C87 and C89

Useful links

• MIST wiki: link
• MIST cores and firmwares: link