uCboard and Remote TCP in PICSimLab: C51, Z80, STM8 and Ripes
The last two entries in PICSimLab’s board list are its most unusual. The uCboard is a generic board for three non-PIC, non-AVR architectures — C51, Z80 and STM8 — driven by the uCsim backend. The Remote TCP board is not a physical board at all: it is a virtual board through which an external simulator acts as the microcontroller, and it is the one board the official documentation explicitly labels experimental.
Overview
The uCboard gives PICSimLab a home for classic 8051 (C51) code, Z80 code and STM8 code, using the uCsim backend. The Remote TCP board is controlled through a single TCP connection and, per the official documentation, “currently only supports the Risc-V simulator Ripes”, with the remote backend providing experimental support for letting other simulators act as the microcontroller that drives PICSimLab’s board and spare parts.
Supported MCUs
| Board | Microcontrollers / role | Backend |
|---|---|---|
| uCboard | C51, Z80 and STM8S103 (the architectures the board was initially built for) | uCsim |
| Remote TCP (virtual board) | No chip of its own — an external simulator connects over TCP; currently only Ripes (RISC-V) | remote (experimental) |
Backend & debugging
The uCboard’s debugging is a remote console over telnet, provided by uCsim — there is no MPLAB X or GDB path for this board. Its project templates reflect its toolchains: the wizard and template list cover Arduino/SDCC projects for C51 and STM8S103 (SDCC templates were added in v0.9.3), and PlatformIO in VSCode is the stated prerequisite IDE for STM8/C51 boards.
Do not confuse the Remote TCP board with PICSimLab’s remote control interface (rcontrol): rcontrol is a text-command socket (default port 5000) for controlling PICSimLab itself, while the Remote TCP board is the channel through which an external simulator like Ripes plays the role of the microcontroller. They are separate features with separate purposes.
What you can do
- Run and telnet-debug C51, Z80 and STM8S103 programs on the uCboard, with spare parts attached as on any other board.
- Connect Ripes to the Remote TCP board and let a RISC-V simulation drive PICSimLab’s virtual circuit — the only RISC-V board path in PICSimLab (the ESP32-C3 board is a separate, QEMU-based riscv32 chip).
- Use both boards as teaching tools for architectures that the PIC/AVR/STM32 boards do not cover, inside the same spare-parts environment.
Real limits
- Remote TCP is experimental — the documentation says so outright. It currently supports only Ripes. It is not general RISC-V board support, not a range of RISC-V boards, and it should not be presented as a finished feature.
- uCboard scope is the three named architectures. The uCsim simulator upstream supports more core families, but PICSimLab’s board-level documentation names only C51, Z80 and STM8S103 for the uCboard — other uCsim families are not promised as working board configurations.
- Debugging on the uCboard is the telnet console only; if you need breakpoints in an IDE, the PIC, AVR, STM32 and ESP32 boards offer better tooling.
- New to PICSimLab itself? The general workflow on any board is: install from the download page, select board and chip, build outside PICSimLab (it has no code editor), load the firmware, run.
Both boards are built into PICSimLab — install it from the download page and select uCboard or Remote TCP from the board list.