and project completion
FPGA based Disk-Emulator+
operation of the RL01/RL02 Emulator is best
with a VIDEO
in the first version, based on the DE1-Board.
Source based on Quartus
port of the RL-emulator to a SoC/HPS
based on the DE10-Nano
consisting of a CYCLON V FPGA with integrated ARM Cortex-A9 CPU.
the new software and firmware version V2.8E, the DE10-Nano Board
works as an RL disk emulator (slave mode), RL disk reader / cloner
/ writer (master mode). The
difference between slave and master mode is that in slave mode a
real up and running DEC PDP-11 / -8 or VAX system must be
operation of emulated and real RL01/RL02 disk drives is possible
in both cases without any problems.
software supports reading and writing of the disk image format
.DSK. This also enables a simple connection to the SIMH
detailed description with examples can be found in the Manual
The additionally required interface board is plugged onto the
40-pin GPIO, see picture. This interface board mainly consists of
level converters and provides the 12 RL bus signals with the
correct logic-level. The entire firmware
and software based
on a Quartus V16.1 environment is open source and is also
available on GitHub.
are also available for a possible replica. Of course, it doesn't
make sense to write on an old/real RL01/RL02 disk drive. I just
implemented it as a personal challenge. In addition, I currently
have no access to a real RL01/RL02 disk due to the corona
pandemic. Perhaps someone would like to continue the project in