# Leningrad2-Upgrade-Kit ## Memory Expansions and AY/TS for Leningrad-2. > [English](README.en.md) | [Русский](README.md) This repository contains hardware expansion board projects designed for the RAM and sound upgrade of the "Leningrad-2" home computer. These modules allow you to upgrade the stock 48K base model to a full **128KB** or **256KB** system. This expansion is essential for running modern homebrew games, advanced demos, and heavy software. The boards are designed with a primary goal: minimizing messy wire-wrap modifications ("spaghetti wiring"). They connect directly to the system expansion slot, transforming the basic Leningrad-2 48K into a powerhouse 128K+ class machine. *** ## 🎸 All-in-One Module Features * **Memory:** Upgrade to 128KB (Standard Spectrum 128 mapping) or 256KB using classic DRAM chips. * **Sound:** Integrated AY-3-8910 sound chip (or YM2149F equivalent). * **Turbo Sound (Optional):** Supports dual AY/YM chips to achieve full 6-channel Turbo Sound capabilities. * **Beep Mixer:** The standard motherboard Beeper signal is mixed directly into the main audio channel output. * **Circuitry:** Standard port decoding logic (`#7FFD` for memory paging and `#BFFD`/`#FFFD` for sound chip registers). * **Compatibility:** Full support for games and demos requiring official memory bank switching. *** ## 🧩 Hardware Construction & Connection (Bus Through-Port) The upgrade boards feature a **Bus Through-port** design. They plug directly into the main system connector of the Leningrad-2, while providing an identical expansion slot connector on top. * **Plug-and-Play:** This allows you to stack other peripherals—like BDI (TR-DOS) or DivMMC controllers—directly on top of this expansion board without using flat ribbon cables. * **Motherboard Integration:** Optimized for seamless operation with my custom version of the [Leningrad-2-48k](https://github.com/Alex-2-Graf/LENINGRAD-2-48k). * **Universal Compatibility:** The board can also be wired to any standard vintage or third-party version of the Leningrad-2. In this case, you will only need to manually route a few core control signals according to the provided schematic. *** ## 📦 Modular RAM Replacement (RAM Plug-in Board) As an alternative to chip stacking ("piggybacking"), this project includes a specialized adapter PCB that holds 16x KR565RU5 (КР565РУ5 / 4164) DRAM chips to replace the stock computer memory. * **Installation:** The adapter plugs directly into the original RAM IC sockets (or footprints) on the Leningrad-2 motherboard. * **Universal Fit:** The pin group layout completely matches the original RU5 memory chip placement found across all known Leningrad-2 PCB revisions. * **Key Advantage:** No messy chip stacking. It provides a clean install, a reliable contact interface, and superior cooling/ventilation for the RAM chips. * **Solderless Upgrade:** Equipped with thin male pin headers (PLS-type) that slide perfectly into standard round-hole machined IC sockets on the mainboard. It preserves the clean, aesthetics and long-term hardware reliability. --- ## 🛠️ Project Modules ### 1. Leningrad 2 Expansion 128k & AY-3-8910 (YM2149F) * [Schematics](Ext%20AY%20128k/Leningrad%202%20Ext%20AY%20128k.pdf) | [Placement](Ext%20AY%20128k/Leningrad%202%20Ext%20AY%20128k.html) | [Gerber Files](Ext%20AY%20128k/Leningrad%202%20Ext%20AY%20128k%20gerber.zip) ### 2. Leningrad 2 Expansion 128k & Turbo Sound 2x YM2149F (AY-3-8910) * [Schematics](Ext%20TS%20128k/Leningrad%202%20Ext%20TS%20128k.pdf) | [Placement](Ext%20TS%20128k/Leningrad%202%20Ext%20TS%20128k.html) | [Gerber Files](Ext%20TS%20128k/Leningrad%202%20Ext%20TS%20128k%20Gerber.zip) ### 3. Leningrad 2 Expansion 256k & Turbo Sound 2x YM2149F (AY-3-8910) * [Schematics](Ext%20TS%20256k/Leningrad%202%20Ext%20TS%20256k.pdf) | [Placement](Ext%20TS%20256k/Leningrad%202%20Ext%20TS%20256k.html) | [Gerber Files](Ext%20TS%20256k/Leningrad%202%20Ext%20TS%20256k%20Gerber.zip) ### 4. RAM Plug-in Board 2x64 * [Schematics](RAM%202x64/Leningrad%202%20RAM%202x64.pdf) | [Placement](RAM%202x64/Leningrad%202%20RAM%202x64.html) | [Gerber Files](RAM%202x64/L2\_RAM\_128k\_gerber.zip) --- ## 🔧 Mainboard Preparation * **For my custom [Leningrad-2-48k](https://github.com/Alex-2-Graf/LENINGRAD-2-48k) revision:** Preparation is as simple as configuring the onboard jumpers **JP5 to JP11** (clearly labeled on the PCB silkscreen). * **For stock/vintage motherboards:** Please consult the descriptive documentation and schematics provided in this repository to properly tap the missing address lines. [here](Mod%20128k/README.md) --- ## 💾 Memory Testing Software To verify your new memory configuration, you can use the following diagnostic tools included in the repository: * [GTEST](Mod%20128k/GTEST1_0.ZIP) * [HFT](Mod%20128k/HFT1_02.ZIP)