From 7609761a4846bd66cbaed068d171d067e9fb63ea Mon Sep 17 00:00:00 2001 From: Alex <182795204+Alex-2-Graf@users.noreply.github.com> Date: Sun, 21 Jun 2026 14:06:30 +0200 Subject: [PATCH] Update README.en.md --- README.en.md | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/README.en.md b/README.en.md index 6073412..5dcd6dc 100644 --- a/README.en.md +++ b/README.en.md @@ -17,15 +17,15 @@ This project is an attempt to merge the aesthetics of the classic "Leningrad-2" The Phase-Locked Loop (PLL / ФАПЧ) is the most critical and sensitive part of any Spectrum floppy controller. The quality of data and clock pulse separation determines whether the drive can reliably read old, worn-out floppy disks or modern 3.5" disk drives. * **ver.1A.1** — *Classic discrete logic circuit.* - ([iBOM](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [Schematics](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [Gerber](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS)) + ([iBOM](Export/A/BDI%20Leningrad-2%201A-1.html) / [Schematics](Export/A/BDI%20Leningrad-2%201A-1.pdf) / [Gerber](Gerber/A/BDI_L2_1A_1_Gerber.zip)) * **ver.1B.1** — *Variant utilizing a dedicated FDC9216B Data Separator chip.* - ([iBOM](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [Schematics](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [Gerber](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS)) + ([iBOM](Export/B/BDI%20Leningrad-2%201B-1%20(FDC9216B).html) / [Schematics](Export/B/BDI%20Leningrad-2%201B-1%20(FDC9216B).pdf) / [Gerber](Gerber/B/BDI_L2_1B_1_Gerber.zip)) * **ver.1C.1** — *Variant featuring a PLL based on the RT4A / КР556РТ4А PROM (C48).* - ([iBOM](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [Schematics](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [Gerber](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [RT4A Firmware](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS)) + ([iBOM](Export/C/BDI%20Leningrad-2%201C-1%20(%D0%A0%D0%A24%D0%90)(C48).html) / [Schematics](Export/C/BDI%20Leningrad-2%201C-1%20(%D0%A0%D0%A24%D0%90)(C48).pdf) / [Gerber](Gerber/C/BDI_L2_1C_1_Gerber.zip) / [РТ4А](Export/C/556RT4.bin)) * **ver.1D.1** — *Variant featuring a PLL based on the RT4A / КР556РТ4А PROM (HIMAK).* - ([iBOM](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [Schematics](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [Gerber](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [RT4A Firmware](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS)) + ([iBOM](Export/D/BDI%20Leningrad-2%201D-1%20(%D0%A0%D0%A24%D0%90)(HIMAK).html) / [Schematics](Export/D/BDI%20Leningrad-2%201D-1%20(%D0%A0%D0%A24%D0%90)(HIMAK).pdf) / [Gerber](Gerber/D/BDI_L2_1D_1_Gerber.zip) / [РТ4А](Export/D/556PT4A.bin)) * **ver.1E.1** — *Variant featuring a PLL based on the GAL16V8B PLD (Scorpion layout).* - ([iBOM](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [Schematics](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [Gerber](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS) / [GAL16V8B Firmware](https://github.com/Alex-2-Graf/Leningrad2-BDI-TR-DOS)) + ([iBOM](Export/E/BDI%20Leningrad-2%201E-1(GAL16V8B).html) / [Schematics](Export/E/BDI%20Leningrad-2%201E-1(GAL16V8B).pdf) / [Gerber](Gerber/E/BDI_L2_1E_1_Gerber.zip) / [GAL16V8B](Export/E/fapch.jed)) ⚠️ **Important Note on Version Selection:** Differences in the PLL implementation are only critical if you intend to use real, physical magnetic floppy disk drives (5.25" or 3.5"). If you plan to use a hardware floppy drive emulator (such as a Gotek drive running FlashFloppy firmware), a complex analogue PLL circuit is not required. Emulators output a perfectly stable, clean digital signal that is easily processed by any of the versions above, including the simplest one (**Classic ver.1A.1**). In this case, you can choose the board that is easiest for you to source and assemble. @@ -35,18 +35,21 @@ Differences in the PLL implementation are only critical if you intend to use rea ## Form Factor & Standardization All 5 board versions share identical physical dimensions and mounting hole locations. This design choice allows you to swap one controller revision for another seamlessly within the same computer chassis. - + +![](Images/BDI-TR-DOS.jpg) + ## Technical Specifications & Integration These controllers are designed for seamless, **Plug-and-Play** connection to my customized motherboard projects: -* **Leningrad-2-48k** -* **Leningrad-2-128k-SRAM** +* [Leningrad-2-48k](https://github.com/Alex-2-Graf/LENINGRAD-2-48k) +* [Leningrad-2-128k-SRAM](https://github.com/Alex-2-Graf/Leningrad-2-128k-SRAM) On the motherboards mentioned above, the system bus and control signals are already pre-routed and fully prepared. To connect these controllers to any other third-party or stock version of the Leningrad-2 computer, a minor modification will be required (detailed in the schematics). This primarily involves verifying the presence of core bus signals and manually routing the `+BETA` and `-BETA` control signals. *Note: It is also possible to use a modern hardware WD1793/ВГ93 chip emulator instead of the original IC.* +[VG93-MB8877](https://github.com/Alex-2-Graf/VG93-MB8877-lgt8f328p-emulator) With fully functional components and proper soldering, the board requires no complex tuning or oscilloscope calibration.