Difference between revisions of "PicoCPC"

Revision as of 03:46, 12 April 2025

Rodrik Studio announced its PicoCPC expansion card, which is created with the help of FreddyV (the author of the PicoMEM ISA card for IBM PC).

The PicoCPC use a Pico2, connected via multiplexor. This let enough pin to add an I2S DAC, MicroSD and some more control signals. The Final board will be really different, with RP2350B Directly soldered.

The board can decode any I/O port and of course RAM/ROM cycles. As it use a Pico2, its RAM is doubled vs Pico1 and it can access a 8MB PSRAM as well.

The PicoCPC does NOT use a CH376 chip, everything is done with the Pico itself. PicoCPC handles FAT12, 16, 32, ExtFS. CH376 will be emulated on the board, with nothing to do at the CPC side.

There is no external ROM, so the microntroller access the emulated RAM/ROM and USB/MicroSD at the same time: Direct write from the uSD to the CPC emulated RAM at 3MB/s (For example).

The PicoCPC is clocked at 366Mhz. So it is not as powerful as the RSF3 clocked at 480Mhz. But it is more powerful than the M4 Board clocked at 168Mhz. Source

Features

It now has :

• ROM Emulation
• RAM Emulation (464/6128), all modes, except C3 mode for now
• Floppy disk controller emulation, supporting .DSK and even most of the copy protected games. (on 464)
• Create Floppy "pack" and swap between them with a button
• Navigate in the SD and run games from it
• Setup program helping to do the initial config if there is no config file on the SD (With graphics and music)
• Various commands, to list and load the ROM and Disk images
• Reset button

C3 mode to arrive in the next hardware release (update 09/04/2025: C3 mode works perfectly fine). And much more for the final hardware release: vocal synthesizer, cpr cartridges, usb mouse, wifi, nfc, ...

The Pimoroni hardware is also being evaluated.

News

Here’s the translation into English of the description of the 07/03/2025 video:

It’s still far from being finished, but it’s progressing well.

What’s still missing:
*Loading and unloading ROMs from BASIC
*Copying files between SD and floppy disk
*Saving files to SD (for now, the Pico can only read and launch)
*Formatting floppy disks
*Displays on the I2C screen during the Wizard
*All the sound part
*All the Wi-Fi part
*All the NFC part

Prototype 2 will require a major change on the I/O side but should normally open up more possibilities, like the C3 memory mode on 464/664, switching to 512KB of extended memory, and sound.

At the moment, I’m aiming for June as a tentative date. Even if the code isn’t finished, the hardware should be.

In the comments of that video, Rodrik said:

• "When it works on all CPCs, including the Plus models, and the hardware is more or less final, I’m aiming for June."
• "The features will evolve; I wrote that in the description. The next big thing will be sound—voice synthesizer—but also a second AY chip and maybe some other quirky stuff like Adlib. Then Wi-Fi and NFC."
• "I plan to add Wi-Fi later if possible, and also USB, which is simpler than micro SD for transferring things."
• "I can even say it’s very likely that Plus cartridges will be emulated soon."
• "Wi-Fi is planned for the longer term; the separate Wi-Fi module for Pico2 isn’t available yet."
• "There are too many boards, often too expensive, hard to find, and with different features. The idea is that the PicoCPC should cost half the price of a DDI5."
• "I didn't check the price of DDI-5, but this one will be around 70€."
• "I will have a distributor in UK, so no problem."
• "When the board is ready, I will open-source both ROMs, the PicoCPC and the Wizard."
• "It’s coming along, but it’ll take a few more months. The final board will be pretty high-tech with 4 layers, etc., and some surprises like connectivity features."
• "There will be a case around it to make it look like a peripheral from back in the day."
• "The HDD part isn’t great; binaries that load other binaries won’t work. In the end, I could only put a few games on it."

On 12/04/2025, Rodrik posted on CPCwiki forum:

I wanted to clarify few things, there is no interest list, nowhere to register to. When the card is ready enough, it will be made available via resellers in France, UK and maybe US.
I still don't know when this will happen, the card did progress of lot since the start in December last year, this means 4 months ago. But I think 3 more months at least are required to make it work properly on all CPC flavors.

The card is currently limited by the RB2350, I do not have enough gpio, so I either use an oled screen, either I2S DAC, either use the pins to drive some signals on the bus. So it requires a new revision with e 2350B soldered on board.

Feature list is unknown yet, but it will grow over time. The card will be available with lot of hardware, but only future firmware revision may make use of it.

Links

• PicoCPC project presentation - 16/01/2025
• PicoCPC project update - 07/03/2025
• Topic on CPCwiki forum