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View this project on CADLAB.io.

Neotron Pico

A Neotron system powered by the Raspberry Pi Pico, in a micro-ATX form-factor.

The Neotron Pico is based around the idea of the Neotron-32, but using a low-cost Raspberry Pi Pico instead of a Texas Instuments Tiva-C Launchpad. It also stretches out to full micro-ATX size, and adds more expansion slots so that you can easily design and add your own peripherals.

Bare PCB Photo

3D PCB View

Top-Down PCB View

Hardware for sale

Sometimes I have kits on Tindie, and sometimes there are kits or complete boards on Elecrow.

Design

The Raspberry Pi Pico is the core of the Neotron Pico. It uses PIO statemachines to generate 12-bit Super VGA video, and digital 16 bit 48 kHz stereo audio. It also has both I²C and SPI buses. SPI chipselects and IRQs are handled by an SPI-to-GPIO expander. This provides eight chip-selects and eight IRQs, to support up to eight expansion slots or peripherals. The eight chip-selects can be globally disabled, allowing the Pico to talk to either the I/O exander, or the selected expansion slot. The board has an SD Card fitted in the 'Slot 1' position, and the Board Management Controller in the 'Slot 0' position, leaving 'Slot 2' through to 'Slot 7' available for expansion. Each expansion slot has both I²C and SPI, along with unique chip-select and IRQ signals.

Software

The Neotron Pico is designed to run the Neotron OS - a CP/M or MS-DOS alike OS written in Rust. But, being open-hardware, you can program your Neotron Pico to do pretty much anything.

Specs

  • Dual Cortex-M0+
    • One dedicated for video/audio
    • One available for OS/Application use
  • 264 KiB SRAM
  • 2 MiB Boot ROM
  • Micro-ATX form-factor
  • SD Card slot for storage
  • 12V DC input
  • SPI and I²C based expansion bus
    • Four externally accessible expansion slots
    • Debug headers with signals for two more slots
  • Dual PS/2 ports for Keyboard + Mouse
  • 16-bit 48 kHz stereo audio headphone out, line out, line in, and microphone in
  • 12-bit (4096 colour) VGA video output
    • Capable of 40x25, 80x25 and 80x50 text modes
    • Capable of 640x480 @ 60 Hz 16-colour, 320x240 @ 60 Hz / 300x200 @ 70 Hz 256-colour graphics modes
  • Designed to run the Neotron OS
  • Open Source Hardware
  • Perfectly suitable for passive cooling
  • Low power
  • Designed for hand assembly

Components in detail

Processor

The main processor module is the Raspberry Pi Pico, which features:

  • A Raspberry Pi Silicon RP2040 SoC
    • Dual-core Cortex-M0+ @ 133 MHz
    • 264 KiB internal SRAM
    • No internal Flash
    • USB 1.1
    • SPI, UART, I²C and Programmable I/O peripherals
  • 26 GPIO pins
  • 2 MiB QSPI Flash
  • On-board LED
  • On-board 5V to 3.3V regulator
  • USB 2.0 Full-speed OTG micro-AB port
  • 4.00 USD / 3.60 GBP retail price

The limited I/O on the Pico (we are using half the available pins just for the video output) is supplemented using a Microchip MCP23S17 SPI to GPIO expander, and an octal buffer. See the I/O Expanders section for more details.

Pin Name Signal Function
01 GP0 VGA_HSYNC VGA Horizontal Sync (31.5 kHz)
02 GP1 VGA_VSYNC VGA Vertical Sync (60 Hz/70 Hz)
04 GP2 VGA_RED0 Digital VGA signal, Red channel LSB
05 GP3 VGA_RED1 Digital VGA signal, Red channel
06 GP4 VGA_RED2 Digital VGA signal, Red channel
07 GP5 VGA_RED3 Digital VGA signal, Red channel MSB
09 GP6 VGA_GREEN0 Digital VGA signal, Green channel LSB
10 GP7 VGA_GREEN1 Digital VGA signal, Green channel
11 GP8 VGA_GREEN2 Digital VGA signal, Green channel
12 GP9 VGA_GREEN3 Digital VGA signal, Green channel MSB
14 GP10 VGA_BLUE0 Digital VGA signal, Blue channel LSB
15 GP11 VGA_BLUE1 Digital VGA signal, Blue channel
16 GP12 VGA_BLUE2 Digital VGA signal, Blue channel
17 GP13 VGA_BLUE3 Digital VGA signal, Blue channel MSB
19 GP14 I2C_SDA I²C Data
20 GP15 I2C_SCL I²C Clock
21 GP16 SPI_CIPO SPI Data In
22 GP17 nSPI_CS_IO Low selects MCP23S17, High selects Peripherals
24 GP18 SPI_CLK SPI Clock
25 GP19 SPI_COPI SPI Data Out
26 GP20 nIRQ_IO Interrupt Request Input from MCP23S17
27 GP21 nOUTPUT_EN Enable buffered CS outputs from MCP23S17
29 GP22 I2S_ADC_DATA Digital Audio Input
31 GP26 I2S_DAC_DATA Digital Audio Output
32 GP27 I2S_BIT_CLOCK Digital Audio Bit Clock (1.536MHz)
34 GP28 I2S_LR_CLOCK Digital Audio Sync (96kHz)

Super VGA output

The Raspberry Pi Silicon RP2040 generates 12-bit VGA video at a range of standard resolutions (including 640x480 @ 60 Hz).

  • 15-pin D-Sub VGA interface
  • 12-bit (4-4-4) RGB R2R DAC
  • 3peak TPF133A or Texas Instruments THS7316 RGB video buffer
    • 36 MHz bandwidth - 1024x768@60Hz maximum
    • 6dB gain
    • Drives 75 ohm standard VGA interface
    • SOIC-8 package (1.27mm pitch)
  • Texas Instruments TPD7S019 Sync/DDC level shifter and RGB EMC filter
    • SSOP-16 package (0.635mm pitch)

The design could easily be adapted to remove the TPF133A/THS7316 video buffer and the TPD7S019 level shifter/filter, and instead use the 1BitSquared DVI PMOD board if you prefer a DVI output (using an HDMI connector).

Audio Codec

The audio subsystem offers 16-bit 48 kHz stereo audio in and out through a classic blue/green/pink triple 3.5mm TRS jack. Input and Output volume can be software controlled.

  • Texas Instruments TLV320AIC23B
    • I²S + I²C interface
    • Amplified 32mW headphone output and line out
    • Microphone in and line in
    • TSSOP-28 package (0.635mm pitch)
  • Triple 3.5mm TRS jack (Kycon STX-4335-5BGP-S1)
    • Headphone Out (green)
    • Line In (blue)
    • Microphone In (pink)
  • AC'97 Pin Header for ATX cases with Audio Jacks
    • Headphone Out
    • Microphone In
  • Extra line-level output pin header (e.g. for additional RCA audio jacks - operates in addition to 3.5mm headphone jack output)
  • Internal line-level input pin header (e.g. for CD-ROM audio - disabled when 3.5mm line-in jack in-use)

Board Management Controller

Power-on Reset sequencing, soft shutdown, voltage monitoring and PS/2 interfacing is handled by a separate STM32F0 SoC.

  • ST Micro STM32F0 (STM32F030K6T6) microcontroller
    • 32-bit Arm Cortex-M0+ Core
    • 3.3V I/O (5V tolerant)
    • 32 KiB Flash
    • 4 KiB SRAM
    • LQFP-32 package (0.8mm pitch)
  • Controls two PS/2 ports
  • Monitors 5V and 3.3V rails
  • Controls system reset, soft-on and soft-off for main CPU
    • Can turn the main 5V regulator on and off
    • Runs from 3.3V stand-by regulator
  • SPI interface (with dedicated IRQ line) with main CPU
  • Secondary I²C bus, connected to VGA DDC pins
Pin Name Signal Function
02 PF0 BUTTON_nPWR Power Button Input (active low)
03 PF1 BUTTON_nRST Reset Button Input (active low)
06 PA0 MON_3V3 3.3V rail monitor Input (1.65V nominal)
07 PA1 MON_5V 5.0V rail monitor Input (1.65V nominal)
08 PA2 SYS_nRESET System Reset Output (active low)
09 PA3 DC_ON Enable 5.0V PSU Output (active high)
10 PA4 SPI1_nCS SPI Chip Select Input (active low)
11 PA5 SPI1_SCK SPI Clock Input
12 PA6 SPI1_CIPO SPI Data Output
13 PA7 SPI1_COPI SPI Data Input
14 PB0 LED0 PWM output for first Status LED
15 PB1 LED1 PWM output for second Status LED
18 PA8 IRQ_nHOST Interrupt Output to the Host (active low)
19 PA9 I2C1_SCL I²C Clock
20 PA10 I2C1_SDA I²C Data
21 PA11 USART1_CTS UART Clear-to-Send Output
22 PA12 USART1_RTS UART Ready-to-Receive Input
23 PA13 SWDIO SWD Progamming Data Input
24 PA14 SWCLK SWD Programming Clock Input
25 PA15 PS2_CLK0 Keyboard Clock Input
26 PB3 PS2_CLK1 Mouse Clock Input
27 PB4 PS2_DAT0 Keyboard Data Input
28 PB5 PS2_DAT1 Mouse Data Input
29 PB6 USART1_TX UART Transmit Output
30 PB7 USART1_RX UART Receive Input

Note that in the above table, the UART signals are wired as Data Terminal Equipment (DTE).

This design should also be pin-compatible with the following SoCs (although the software may need recompiling):

  • STM32F042K4Tx
  • STM32F042K6Tx
  • STM32L071KBTx
  • STM32L071KZTx
  • STM32L072KZTx
  • STM32L081KZTx
  • STM32L082KZTx

Note that not all STM32 pins are 5V-tolerant, and the PS/2 protocol is a 5V open-collector system, so ensure that whichever part you pick has 5V-tolerant pins (marked FT or FTt in the datasheet) for the PS/2 signals. All of the parts above should be OK, but they haven't been tested. Let us know if you try one!

PS/2 Keyboard and Mouse

  • Kycon two-port stacked 6-pin DIN sockets (Kycon KMDGX-6S/6S-S4N)
  • Controlled via Board Management Controller

Power Supply

  • 12V nominal input
    • 8V to 30V is OK if you don't need the 12V rail
    • Fused with a PTC at 2A
    • Reverse polarity protected
  • 3A 5.0V main regulator (DC-DC switch-mode regulator module)
    • Morsun K7805-3AR3
  • 200mA 3.3V stand-by regulator (a micropower linear regulator running from 12V input)
  • 1A 3.3V regulator (a high-power 1117 type linear regulator running from 5.0V rail)
  • Controlled and monitored by the Board Management Controller

Real Time Clock

The Neotron Pico can retain time/date settings when fully powered off, using a Real Time Clock chip and a CR2032 lithium coin cell. This also retains system settings in a very low-power SRAM built into the Real Time Clock chip.

  • MCP7940N or DS1307Z+ Real Time Clock
  • CR2032 battery-backup (should be OK for about 10 years)
  • 56 bytes of battery-backed SRAM for system settings

I/O Expander

  • MCP23S17 SPI to GPIO expander (SOIC-28)
  • 74HC138 3:8 decoder (SOIC-16)
  • Five debug LEDs
  • Eight Chip-Select outputs (active low)
  • Eight IRQ inputs (active high or active low)

Because we used so many pins on the Pico for Audio and Video, we don't have enough pins to use for Chip Select lines. Each device we wish to communicate with on the SPI bus must have a unique chip select line and so have limited lines means we could only have a limited number of SPI devices.

However, in this design, we cheat and use a Microchip MCP23S17 I/O expander. This is an SPI peripheral with 16 GPIO pins that can be controlled by sending it commands over SPI. It also has an IRQ output which be programmed to fire when the input pins match a certain state. The MCP23S18 (with open-drain outputs) will not work - it has a different pinout.

The problem would come when the Pico has finished talking to our select SPI device - how does it tell the MCP23S17 to release the current chip select, without the SPI bus traffic also going to the currently selected expansion slot? We resolve this by using a simple 8-bit decoder/buffer with an enable pin. This allows the Pico to disconnect all of the chip select signals at once, regardless of the output of the MCP23S17. Once this is disabled, we know we are talking to only the MCP23S17 and the Pico can command it to select the next chip select of interest to us.

Interrupts are also processed through the MCP23S17. We configure the device to provide an IRQ (edge, active low) whenever any of the eight IRQ inputs are active (programmable for edge or level, active high/rising or low/falling). When the Pico receives an IRQ from the MCP23S17, it must do a read of the pins (using SPI) to find out which device actually raised the interrupt. This model is similar to that used in the IBM PC - where the Intel 8088 must talk to an Intel 8259A programmable interrupt controller over the ISA bus to find out which interrupt was raised - except that in our case, our CPU is very fast and our bus is pretty slow, so our interrupt latency isn't very good. Worse, if there is a big SPI transaction happening (such as transferring a 512 byte block from an SD card) when an interrupt fires, the Pico will have to wait for that to complete before it can talk to the MCP23S17 to handle the IRQ. That or it could just drop the SPI transaction mid-way through and re-try it later (if your expansion device can tolerate such rudeness).

+------+                                  +-----+
|      |----------/OUTPUT_EN------------->|     |
|      |                                  |     |
|      |           +----------+           |     |
|      |           |          |           |     |
|      |           |          |--CS_SEL0->|     |----/CS0---------------------------------+
|      |           |          |           |     |                                         |
|      |           |          |--CS_SEL1->|  D  |----/CS1-----------------------------+   |
|      |           |          |           |  E  |                                     |   |
|      |           |          |--CS_SEL2->|  C  |----/CS2-------------------------+   |   |
|      |           |          |           |  O  |                                 |   |   |
|      |           |          |           |  D  |----/CS3---------------------+   |   |   |
|      |           |          |           |  E  |                             |   |   |   |
|      |           |          |           |  R  |----/CS4-----------------+   |   |   |   |
|      |           |          |           |     |                         |   |   |   |   |
|      |           |          |           |     |----/CS5-------------+   |   |   |   |   |
|      |           |          |           |     |                     |   |   |   |   |   |
|      |           |          |           |     |----/CS6---------+   |   |   |   |   |   |
| Pico |           | MCP23S17 |           |     |                 |   |   |   |   |   |   |
|      |           |          |           |     |----/CS7-----+   |   |   |   |   |   |   |
|      |           |          |           +-----+             v   v   v   v   v   v   v   v
|      |           |          |                             +---+---+---+---+---+---+---+---+
|      |--/IOCS--->|          |                             | S | S | S | S | S | S | S | S |
|      |<---IRQ----|          |                             | l | l | l | l | l | l | l | l |
|      |<===SPI===>|          |<============SPI============>| o | o | o | o | o | o | o | o |
|      |           |          |                             | t | t | t | t | t | t | t | t |
|      |           |          |                             |   |   |   |   |   |   |   |   |
|      |           |          |                             | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|      |           |          |                             +---+---+---+---+---+---+---+---+
|      |           |          |<---IRQ7-----------------------+   |   |   |   |   |   |   |
|      |           |          |                                   |   |   |   |   |   |   |
|      |           |          |<---IRQ6---------------------------+   |   |   |   |   |   |
|      |           |          |                                       |   |   |   |   |   |
|      |           |          |<---IRQ5-------------------------------+   |   |   |   |   |
|      |           |          |                                           |   |   |   |   |
|      |           |          |<---IRQ4-----------------------------------+   |   |   |   |
|      |           |          |                                               |   |   |   |
|      |           |          |<---IRQ3---------------------------------------+   |   |   |
|      |           |          |                                                   |   |   |
|      |           |          |<---IRQ2-------------------------------------------+   |   |
|      |           |          |                                                       |   |
|      |           |          |<---IRQ1-----------------------------------------------+   |
|      |           |          |                                                           |
|      |           |          |<---IRQ0---------------------------------------------------+
+------+           +----------+

Expansion

The seven expansion sockets allow you to add on I²C or SPI based devices at a later date. Each provides a single chip-select and a single IRQ line - the motherboard design should ensure each socket gets a unique signal for each of these. Each expansion device should also contain a AT24C256 or similar EEPROM device. To allow these EEPROM devices to be scanned, each slot also contains three EEPROM_ADDRESS pins, tied to Vcc or GND in a unique combination. These should be connected through to the EEPROM address lines on your AT24C256, thus ensuring that each expansion card has its EEPROM at a unique address - 0x50 on Slot 0 through to a maximum possible 0x57 for Slot 7. Where your board has on-board devices, you should fit an AT24C256 EEPROM for each device so that the on-board devices can be discovered, exactly as if they were on an expansion card.

The expansion slot is a simple 2x10 header. We suggest the use of a TE card-edge connector, but you could equally use two 1x10 pin-headers if desired.

The expansion connector pinout is:

               +--------+
     SPI_COPI -| 1    2 |- GND
     SPI_CIPO -| 3    4 |- GND
      SPI_CLK -| 5    6 |- GND
      ~SPI_CS -| 7    8 |- ~IRQ
      I2C_SDA -| 9   10 |- I2C_SCL
 EEPROM_ADDR0 -| 11  12 |- EEPROM_ADDR1
 EEPROM_ADDR2 -| 13  14 |- ~RESET
           5V -| 15  16 |- 5V
          3V3 -| 17  18 |- 3V3
          GND -| 19  20 |- GND
               +--------+

Four expansion slots line up with the ATX case expansion brackets, allowing you to use cards with external connectors. Note that these are aligned the "PCI way around" with components facing away from the board's I/O area, rather than the "ISA way around" which would have the components facing the I/O area. A further three of the expansion slots are available for internal use only.

Slot Assignments

Slot 0

The signals for Slot 0 are connected to the Board Management Controller. Both CS and IRQ are connected.

Slot 1

The signals for Slot 1 are connected to the on-board SD Card Slot. CS 1 is connected to the card's DAT3 pin, and IRQ 1 is connected to the Card Detect pin on the card slot.

Slot 2

Slot 2 is the right-most Expansion Slot.

Slot 3

Slot 3 is the right-most-but-one Expansion Slot.

Slot 4

Slot 4 is the left-most-but-one Expansion Slot.

Slot 5

Slot 5 is the left-most Expansion Slot.

Slot 6

Slot 6 is not fitted. SPI Chip Select 6 and IRQ 6 are only available on the test headers.

Slot 7

Slot 7 is not fitted. SPI Chip Select 7 and IRQ 7 are only available on the test headers.

Main I²C Bus

All I²C device address given below are 7-bit values. Note that with I²C, the first byte in a message is the control byte; this is comprised of the device address in the top seven bits, and an extra bit at the bottom to indicate read (1) or write (0).

The memory addresses given are 8-bit values used to access the contents of an I²C device, and are usually supplied as the second byte in a message.

  • Device Address 0x1A - TLV320AIC23
    • Memory Address 0x00 - Left line input channel volume control
    • Memory Address 0x01 - Right line input channel volume control
    • Memory Address 0x02 - Left channel headphone volume control
    • Memory Address 0x03 - Right channel headphone volume control
    • Memory Address 0x04 - Analog audio path control
    • Memory Address 0x05 - Digital audio path control
    • Memory Address 0x06 - Power down control
    • Memory Address 0x07 - Digital audio interface format
    • Memory Address 0x08 - Sample rate control
    • Memory Address 0x09 - Digital interface activation
    • Memory Address 0x0F - Reset register
  • Device Address 0x52 - Slot 2 ID EEPROM
    • Memory Addresses 0x00..0xFF - Expansion Card Specification in NEID (Neotron Expansion ID) format
  • Device Address 0x53 - Slot 3 ID EEPROM
    • Memory Addresses as per Slot 1
  • Device Address 0x54 - Slot 4 ID EEPROM
    • Memory Addresses as per Slot 1
  • Device Address 0x55 - Slot 5 ID EEPROM
    • Memory Addresses as per Slot 1
  • Device Address 0x68 - Real-time Clock (DS1307+ variant)
    • Memory Addresses 0x00..0x07 - Clock Configuration
    • Memory Addresses 0x08..0x3F - Battery-backed SRAM
  • Device Address 0x6F - Real-time Clock (MCP7940N variant)
    • Memory Addresses 0x00..0x1F - Clock Configuration
    • Memory Addresses 0x20..0x5F - Battery-backed SRAM

Secondary I²C Bus

There is a second I²C bus, driven by the Board Management Controller. This is connected to the Display Data Connection (DDC) pins on the VGA interface, allowing the reading of the VGA monitor's EDID block. This is typically at device address 0x50

Expansion Ideas

Why not design and build your own expansion card? You could try designing:

  • A dual Atari/SEGA 9-pin Joypad Interface
  • A Mikro Electronika Click adaptor, allow many of the range of Click boards to be fitted
  • A Wi-Fi/Bluetooth card, using an Espressif ESP32-C3
  • A second processor card - perhaps with a RISC-V microcontroller, or classic Zilog Z80
  • An OPL2 or OPL3 based FM synthesiser card
  • An ISA adaptor card (taking an ISA card at right-angles, i.e. parallel to the base board) - a simple microcontroller should be able to bit-bang the ISA bus at 8 MHz and offer an SPI peripheral interface to the Neotron Expansion Slot
  • An IDE interface card, allowing 40-pin IDE Hard Disk Drives and CD-ROM drives to be used - this will be quite similar to an ISA bus adaptor
  • A floppy drive controller card - either using an eSPI Super I/O chip, or connecting a legacy ISA bus floppy controller as per the ISA adaptor
  • A video card for a second monitor output, perhaps based on the CPLD used in the VGAtonic

Automated Builds

This project treats a PCB like embedded firmware:

  • The source files are the KiCAD 6 files (in ./Kicad)
  • The compiler is KiCAD 6, plus various automation plug-ins (like KiBom)
  • The build system is KiBot
  • The build outputs are PDF versions of the schematic and the PCB, plus various zipped Gerber and Drill files.

We do not check build outputs into this repository - ever. Instead, we run a Github Action which uses KiBot to generate our outputs. On a regular Pull Request, the build outputs are stored as artefacts against the particular Github Action run. When a new version is tagged, the build outputs are stored as files against a Github Release.

You can build locally using the KiBot docker container:

~/Neotron-Pico $ docker run --rm -ti -v $(pwd):/work setsoft/kicad_auto:dev_k6
root@12345678:/# cd /work/Kicad
root@12345678:/work/Kicad# kibot -c docs.kibot.yml -e neotron-pico.kicad_sch -b neotron-pico.kicad_pcb -d docs

This will build everything and put it in the ./Kicad/docs directory.

Changelog

See CHANGELOG.md for a list of detailed changes.

Licence

These documents, schematics and PCB designs are Copyright (c) The Neotron Developers, 2022.

CC BY-SA 4.0

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

That means you are free to:

  • share - copy and redistribute the material in any medium or format
  • adapt — remix, transform, and build upon the material for any purpose, even commercially

Please note that the models provided in the Kicad/Models directory are from various manufacturers. Terms and conditions for the use of the models are as specified by the original manufacturer/author.

NOTE: Releases are provided free-of-charge, and without any kind of warranty - explicit or implied. It is imperative you validate the design for yourself before placing an order or using/adapting/copying any of the designs herein. The Neotron Developers cannot be held responsible if you build or remix our designs and it doesn't turn out how you expected. This is a work-in-progress and you will most likely need to fix something, somewhere.

Contribution Agreement

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be licensed as above, without any additional terms or conditions.

Articles and Reviews

Datasheets and References

Assembly instructions

See ASSEMBLY.md for instructions on how to assemble the board.

How hard is this to solder?

Typically, I get the boards from JLCPCB with most of the surface-mount components already fitted. This includes all the LEDS, small inductors, resistors and small capacitors (all 0805 size), the transistors (all SOT-23), and whichever of the larger ICs they happen to have in stock. All that's left is the larger ICs, and the through-hole connectors.

In the release area, you will see a JLCPCB specific bill-of-materials (BoM), which includes only the parts with a Cxxxx format LCSC/JLCPCB part number. You upload this, along with the CPL position file for those parts, when placing your order.

If you want to order bare boards, it is designed to be hand-solderable. That's why there are no SMD parts smaller than 0805.

Part Footprint Size (mm) Pitch (mm)
MCP23S17 SOIC-28 18x7.5 1.27
Jellybeans 0805 2.0x1.2 N/A
Transistors SOT-23 3.1x1.4 1.80
74HC138 SOIC-16 3.9x9.9 1.27
THS7316 SOIC-8 3.9x4.9 1.27
DS1307Z SOIC-8 3.9x4.9 1.27
STM32F031K6T6 LQFP-32 7.0x7.0 0.80
TLV320AIC23BPW TSSOP-28 4.4x9.7 0.65
TPD7S019 SSOP-16 3.9x4.9 0.635

But can I buy the parts yet?

Feel free to click these (unaffiliated) links and see for yourself!

Component Manufacturer Part Number Octopart LCSC JLCPCB Digikey Mouser RS Farnell
Main CPU Raspberry Pi Pico (SC0915) Link N/A N/A N/A Link
BMC ST Micro STM32F030K6T6 Link C46830 C46830 Tray Link Link Link
BMC (alt) ST Micro STM32F031K6T6 Link C526904 C526904 Tray Link Link Link
Video Amplifier Texas Instruments THS7316 Link C544774 C544774 Tape N/A N/A N/A
Video Amplifier (alt 1) 3Peak TPF133A Link C155446 C155446 N/A N/A N/A N/A
Video Amplifier (alt 2) DIOO DIO2663 Link C444605 C444605 N/A N/A N/A N/A
Video ESD Filter Texas Instruments TPD7S019-15DBQR Link C337499 C337499 Tape Link N/A Link
GPIO Expander Microchip MCP23S17/SO Link C145413 C145413 Tube Link Link Link
Audio CODEC Texas Instruments TLV320AIC23BPW Link C9915 C9915 Tape Link Link Link
Real Time Clock Microchip MCP7940N-I/P Link C153264 C153264 Tube Link Link Link
Real Time Clock (alt) Dallas DS1307Z+ Link C9868 C9868 Tube Link Link Link
Power Supply Mornsun K7805-3AR3 Link C2684867 C2684867 Tube N/A N/A N/A