Disk – Emulators

The Idea:

Maintenance of the software from the years 1980 - 1990

The Need:

Porting the old disk technology to new technology

The Execution:

Simulation of Disk Drives based on FPGA


The latest emulator developments are all based on the DE10-Nano board with CYCLON V FPGA and integrated ARM Cortex-A9 CPU. My emulators for RL01/RL02-Disk und MFM-Disk are able to operate in slave mode as an emulator and in master mode as a reader/cloner. I haven't pursued the idea of merging both interface boards any further. The reason here was no feedback. All products are OPEN SOURCE and are also stored on GitHub with the complete Quartus Environment. The used Quartus version is V16.1. Of Course all applications can be transferred to the new Quartus version V2.1 or higher. If it is necessary, only a re-compile is required. A “ready for use” configured SD card image for the DE10-Nano board is also available. Download the image and copy it to an SD card using Win32DiskImager, for example. Login: root, PW: pdp11
Newly added are the emulators for the DEC RK05 disk and RX01/RX02 floppy disks. The RK05 emulator exists as a prototype and has not yet been tested with an RK-11 because no corresponding PDP-11 UNIBUS system is available. It's similar with the RX01/RX02 emulator and I stopped further development because there was no demand. I also rejected an idea to develop an universal 40-pin level converter board to plug on interface boards for RL01/RL02, MFM disks, RK05 and RX01/Rx02 and ….

My main concern was to preserve the old software and I think I succeeded. I am now retired and other things have become more important in the rest of my life and the further development of my projects is no longer my primary focus.

Final note:
Unfortunately, I had to realize again and again that there was and is no collaboration at all, but very often just a tussle over competence, especially on the Internet and also in the forums such as the RK05 Emulator. That was often bad during my professional career, but now as a pensioner when it's all about maintaining the old computer software/hardware, I lack understanding and that's why I'm withdrawing. Many ideas remain open, but I can't/couldn't realize it on my own.