From bdac7f67a983b4b663dfc3195dd247b21862d4bb Mon Sep 17 00:00:00 2001 From: Alex-2-Graf <182795204+Alex-2-Graf@users.noreply.github.com> Date: Sun, 21 Jun 2026 15:58:57 +0200 Subject: [PATCH] en --- README.en.md | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++ README.md | 4 ++- 2 files changed, 85 insertions(+), 1 deletion(-) create mode 100644 README.en.md diff --git a/README.en.md b/README.en.md new file mode 100644 index 0000000..f92a686 --- /dev/null +++ b/README.en.md @@ -0,0 +1,82 @@ +# VG93-MB8877-lgt8f328p-emulator + +## Hardware layout for Evgeny Ugryumov's WD1793/MB8877/KR1818VG93 floppy disk controller emulator based on the LGT8F328P MCU. + +> [English](README.en.md) | [Русский](README.ru.md) + +This project features a hardware emulator for the Soviet KR1818VG93 (КР1818ВГ93) floppy disk controller chip and its international equivalents, the **Western Digital WD1793** and **Fujitsu MB8877**. Powered by the fast and affordable **LGT8F328P** microcontroller, this adapter board acts as a direct drop-in replacement. It is designed to replace scarce, expensive, or faulty vintage FDC chips in retro-computers like the ZX Spectrum and other compatible 8-bit systems. + +* **Firmware Development:** Evgeny Ugryumov (ZX-FLOPPY group). +* **PCB Layout & Hardware Design:** Alex-2-Graf. + +The adapter board is routed specifically to plug directly into a standard 40-pin IC socket on the host computer board, requiring no permanent modifications to the vintage hardware. + +*** + +## ⚡ Key Features of LGT8F328P + +* **32 MHz Clock Speed:** Provides high-precision bus timing synchronization to accurately match vintage hardware cycles. +* **High Performance Core:** Executes most machine instructions in a single clock cycle. +* **Native 5V Logic:** Provides full signal level compatibility with legacy 8-bit computers without requiring logic level shifters or resistors. +* **Cost-Effective:** The LGT8F328P microcontroller is significantly more affordable and accessible than surviving original WD1793/VG93 silicon chips. + +## 🛠️ Supported Functionality + +* Emulation of core FDC commands for sector reading and writing. +* Accurate tracking of stepper motor control signals (`STEP`, `DIR`). +* Precise hardware emulation of standard drive feedback signals: `READY`, `INDEX`, and `TRACK 00`. + +*** + +## 🔌 Hardware Revisions + +The emulator has evolved through three distinct board layouts: + +### Revision 1 (Not recommended for new builds) +The initial prototype version. Included for historical log purposes. +* [Schematics](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) | [Placement](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) | [Gerber](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) + +### Revision 2 (Diode-based version) +An improved layout utilizing discrete steering diodes to condition signals. +* [Schematics](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) | [Placement](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) | [Gerber](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) + +### Revision 3 (74AHC1G08 logic version - Recommended) +The latest and most stable layout utilizing a tiny 74AHC1G08 AND-gate chip. Since this logic IC comes in two common SMD packages, two distinct PCB options are available: +1. **Ultra-compact layout** using the **SC-70** IC package package: + * [Schematics](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) | [Placement](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) | [Gerber](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) +2. **Standard layout** using the **SOT-23-5** IC package package: + * [Schematics](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) | [Placement](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) | [Gerber](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) + +*** + +## 💾 Flashing Instructions + +To flash the compiled firmware onto the onboard LGT8F328P microcontroller, a specialized ISP programmer is required. + +You can assemble your own programmer using one of these DIY options: +1. An **Arduino-based** programmer using [LarduinoISP](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator). +2. An **RP2040-based** programmer using [LarduinoISP](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator). + +Once your hardware programmer is verified, flash the precompiled binary `.hex` files using the **AVRDUDESS** GUI software tool. + +* **Firmware Binaries:** Available inside the [/Firmware](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) directory. +* **Latest Releases:** Updated software drops can be monitored directly in the **ZX-FLOPPY** community group. +* **Source Material:** Complete design files can be inspected in the [/Sources](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) folder. + +### ⚠️ Interface Modification (Nemo-BDI Correction) +For Beta Disk Interfaces utilizing the **Nemo-BDI** standard architecture, an external hardware patch is required to correct the chip select (`CS`) signal timing. This modification requires a standard **555LA3 / 74LS00** discrete NAND logic gate chip. +* [Modification Schematic](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) + +*** + +## 👥 Credits & Acknowledgments + +* **Evgeny Ugryumov** — Special thanks for his incredible work developing the firmware core inside the **ZX-FLOPPY** project. +* **Alexander (UR4QBP)** — For running extensive hardware testing, experiments, and optimizations. You can find his specific repository fork [here](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator). +* **HRDY (Dmitry)** — For developing the excellent RP2040-based hardware programmer design. + +*** + +## 📜 License + +This project is distributed under the open-source MIT License. See the `LICENSE` file for more details. diff --git a/README.md b/README.md index 144b4b5..aef7bb4 100644 --- a/README.md +++ b/README.md @@ -1,7 +1,9 @@ # VG93-MB8877-lgt8f328p-emulator Hardware layout for Evgeny Ugryumov's WD1793/MB8877/ВГ93 floppy disk controller emulator based on LGT8F328P MCU. - + +> [English](README.en.md) | [Русский](README.md) + --- # Эмулятор контроллера дисковода КР1818ВГ93 (MB8877/WD1793) на чипе LGT8F328P MCU