Karabas Pro
A Profi-compatible ZX Spectrum the size of a 3.5" floppy drive, with FDD and HDD controllers
- Chip
- Altera EP4CE10
- Video
- VGA (50 Hz)
- Memory
- 6 MB SRAM (rev.E+)
- Latest revision
- Ї
- License
- MIT
Karabas Pro is a smaller Profi (Профи) clone: a ZX Spectrum compatible machine with real FDD and HDD controllers, where the CPU and all the logic live inside an Altera FPGA. The board has the dimensions of a real 3.5" floppy drive.
The main firmware is finished. The same machine is also available as the Karabas Pro core on Karabas Go.
What the firmware does
- ZX Spectrum and Profi hi-res video modes with a palette, Profi CMR ports
- FDD controller that works in CP/M and classic modes
- HDD controller on a CF card, for Profi CP/M and PQ-DOS
- PS/2 keyboard, PS/2 mouse as Kempston and serial MS mouse
- VGA output (the monitor must support 50 Hz)
- Turbosound (2 × AY-3-8912), Soundrive and SAA1099
- Kempston and SEGA joysticks
- RTC, SD card through Z-Controller and DivMMC emulation
- Turbo 7 MHz and 14 MHz
- UART for the ESP8266 module, ZiFi API
- OSD menu and full-screen settings
Extra ROM banks
- PQ-DOS BIOS
- Flash Tool by Doctor Max upgrades the FPGA firmware and ROM banks without a programmer
- FDImage Tool by Doctor Max writes TRD, SCL, PRO, TD0 and FDI images to real floppies
Manuals
The user’s manual is available in English and Russian, the developer’s manual in Russian. Both are in the list below.
Files and documentation
- User's manual EN
- User's manual RU
- Developer's manual v1.01, RU
- Latest firmware release v25092420-romain292
- Firmware files
- Schematic rev.ER
- Gerbers rev.Ї
- Interactive BOM rev.ER
- Errata rev.DS
- 3D cases
Photos and renders
Videos
Karabas-Pro Rev.DS by Andy Karpov. Четвертая серия. Корпус и дисковод. Продолжение...
Karabas-Pro Rev.DS by Andy Karpov. Третья серия. Корпус и дисковод.
Karabas-Pro Rev.DS by Andy Karpov. Вторая серия. Чипы, прошивка и включение.
Karabas-Pro Rev.DS by Andy Karpov. Лушпайка, стабы, проверка питания...
Karabas Pro ZXAAA: создание корпуса часть 3.
Karabas Pro ZXAAA: создание корпуса часть 2.
More videos (21)
Karabas Pro начинаем делать корпус. Часть 1. Смотрим крутое демо 22.03.2026
Karabas Pro: сверлим дырки в оргстекле. Часть 2. Выпуск от 23.03.2026
Тестирование Karabas Pro Rev.C методом уверенного пользователя ZX А.А.А.
Продолжение ДВА. Что. Про? Про Что? Про карабас . Что? А! Карабас ПРО! Финальный монтаж Karabas PRO
Про. Что? Что Про? Про Что? Про карабас . Что? А! Карабас ПРО! Монтаж лушпайки на Karabas PRO
Продолжение ....Что Про? Про Что? Про карабас . Что? А! Карабас ПРО! Монтаж лушпайки на Karabas PRO
Скучностим по пайке Карабас ПРО (Паяй, Калантай! #142)
Субботние лушпайки #5. Карабаса Про полушпаю. (Паяй, Калантай! #140)
Карабас, который не Барабас (Паяй, Калантай! #33)
Карабас, который не Барабас (Паяй, Калантай! #32)
Карабас, который не Барабас (Паяй, Калантай! #31)
Карабас, который не Барабас (Паяй, Калантай! #30)
Karabas-Pro ROMain v0.49 by Dr.Max
Karabas-pro ROMain by Dr.Max
ZX Spectrum - Karabas Pro DS. Небольшой обзор. Часть - 5
ZX Spectrum - Karabas Pro DS. Прошивка второй платы. Часть - 4
ZX Spectrum - Karabas Pro DS. Сборка второй платы. Часть - 3
ZX Spectrum - Karabas Pro DS. Сборка второй платы. Часть-2
ZX Spectrum Karabas Pro DS. Сборка второй платы. Часть-1.
ZX Spectrum / Что на дискетках? #2 / TR-DOS / Карабас Про
ZX Spectrum / Что на дискетках? / Карабас Про
Videos by the author and the community on YouTube, in their original languages.
PCB changelog
Karabas-Pro PCB changelog:
Rev.Ї (EU):
- All PCB labels translated to Ukrainian language
Rev.Ё (ER):
- Added russian labels on the board
- Changed TRRS footprints to a universal SMT/THT
- Added a standalone 3.3V LDO for ESP-8266
- Changed uSD footprint
Rev.E:
- Added 2 more SRAM chips, up to 6 MB SRAM total, 4 MB available as host RAM, 1-2 MB as host ROM
- Changed uBus with 5-pin header for secondary UART
- Minimum Cyclone chip is EP4CE10 since this revision
Rev.DS':
- Fixed Q2 footprint
- Updated R nominals for buzzer and tape in for better compatibility
Rev.DS:
- Removed DIP switches from the design
- Added an expansion connector for external joystick
- Added support for SEGA 3-button joysticks (mapped vcc and select pins to atmega)
- Added (optional) tape in/out connectors and logic
- Added on-board buzzer with jumper to disable it
- Increased pads length for so-8 flash ics (to support both W25Q16 and M25P16)
- Added free fpga pins 7,25 to the uBus connector
- Increased an fpga pin_145 (thermal pad) diameter from 3mm to 5mm
Rev.D:
- Added ICs to source the board from 12V power supply instead of 5V
- Added a slide switch to power on/off the board
- Added fuses and supressor to protect the 5V rail from the accidental incorrect power source
- Added more LEDs on the board
- CF card LED mapped to a dedicated CD card “busy” pin
- SD card LED mapped to a /SD_CS signal
- Added a secondary flash chip and jumper
- Added optional 300 Ohm terminators for the FDD
- Added a ferrite filter for the 2.5V rail
- Added more powerful LDO on the 3.3V rail
- Added TurboFDC support
- Added connector with free ESP-12 module pins
- Added a diode assembly to power the RTC chip without battery
- Added a series of additional resistors on CF card /WR, /RD, /CS0, /CS1 pins
Rev.C1:
- SD CMD pin rerouted to a dedicated FPGA pin 115
- CF card now uses 3.3v rails instead of 5v
- CF card pin 44 (/REG) pulled up to 3.3v
Rev.C:
- Added 10k pull-up on /AVR_CS line
- Added 10k pull-ups on BTN1, BTN2 lines
- Changed footprint for DB9 connector
- Added DIP-switches on free FPGA lines
Rev.B:
- Added missing 10k pull-ups on FDC_RDATA,FDC_WPRT, FDC_TR00, FDC_INTRQ, FDC_DRQ
- Changed R25 to 820 Ohm
- Changed R26,R27 to 750 Ohm
- Changed C1,C2 to 10uF
- Moved sound jack a bit left
- Added a restricted zone under the ESP-12 antenna
Rev.A:
- Initial revision