Download

Source

Project source code (latest snapshot):

pdp11-20150729.tar.gz

Bitstreams

pdp11-bitsa-20150729.tar.gz for the Altera/Terasic boards DE0 and DE1

pdp11-bitsx-20150729.tar.gz for the Xilinx/Digilent boards N2B1200, N3B

 

DE0

The de0-1145-rkrl bitstream is an 11/45 with the FP11 floating point unit and either RK05 or RL02 disks; you switch between these by setting SW0 and rebooting by pressing button2. A terminal is included; connect a ps2 keyboard and a vga screen. This bitstream is useful for running RT11, older versions of RSTS and RSX, and of course ancient Unix.

The de0-1170-rpxunofp is an 11/70 with an RP06 disk and the DEUNA. To save space, the FP11 floating point unit is not present. A terminal is included; connect a ps2 keyboard and a vga screen; also, to use the DEUNA, a PMODNIC100 should be connected as follows: (CS) PMOD pin1 to GPIO0 pin 36; (MOSI) PMOD pin2 to GPIO0 pin 35; (MISO) PMOD pin 3 to GPIO0 pin 38; (SCK) PMOD pin 4 to GPIO0 pin 37; (GND) PMOD pin 5 to GPIO0 pin 30; (VCC) GPIO0 PMOD pin 6 to pin 29; PMOD pins 1-6 are the top row. This bitstream is primarily intended to run 2.11BSD, but because the FP11 is missing it requires the floating point simulator in the kernel so you need to apply patches up to at least #445, and then rebuild the kernel with FPSIM YES configured.

DE1

For the DE1, two similar bitstreams de1-1145-rk and de1-1145-rl are available; both are 11/45 with FP11 included, and serial console 9600/8/n/1 on the db9 port. Each bitstream implements a single controller for either RK05 or RL02 drives.

The third bitstream de1-1170-rp is an 11/70 with FP11 and a single RP06 drive, and the DEUNA – connect a PMODNIC100 as follows: (CS) PMOD pin1 to GPIO0 pin 36; (MOSI) PMOD pin2 to GPIO0 pin 35; (MISO) PMOD pin 3 to GPIO0 pin 38; (SCK) PMOD pin 4 to GPIO0 pin 37; (GND) PMOD pin 5 to GPIO0 pin 30; (VCC) GPIO0 PMOD pin 6 to pin 29; PMOD pins 1-6 are the top row.

For the DE1, two sets of each bitstream are available; the ones in directories ending in M9312 contain the (almost) original M9312 boot code, the other directories have my own ‘old’ boot code.

Nexys2-1200

The bitstreams for the Nexys2 board are for the 1200K gate device – the 500K gate device is a bit too small for most PDP11 models. There are three different bitstreams each including the embedded terminal – connect ps2 keyboard and vga screen. The bitstreams n2b1200-1145-rk and n2b1200-1145-rl are 11/45 with FP11 and either RK05 or RL02 drives. The n2b1200-1170-rpxunofp is an 11/70 with a single RP06 drive, no FP11, and DEUNA.

For the sd card, a PMODSD must be connected to port JA1; for the DEUNA, a PMODNIC100 must be connected to port JD1.

The board does not usually power up in a reset state; press the BTN0 button to manually reset it.

Additionally to the bitstreams described above, there is a group of directories ending in M9312; these bitstreams all have the console on the serial port (9600/8/n/1) instead of the embedded terminal, and have the (almost) original M9312 boot code instead of my own ‘old’ boot code; and the n2b1200-1170-rpxu-m9312 does have the FP11.

Nexys-3

There are two bitstreams for the Nexys-3 board: firstly n3b-1145-rl, which is an 11/45 without FP11, and RL controller. It includes the embedded terminal; connect a usb keyboard and vga screen. Nexys-3 has the nice feature of a usb host port to connect the keyboard to; however, I found that several of my keyboards do not work with it. After the bitstream is loaded, keyboard activity is indicated on the LD6 and LD7 leds; if you don’t see these flashing, likely the board does not work with your keyboard. For the sd card, a PMODSD must be connected to port JA1.

The second bitstream n3b-1170-rpxunofp-m9312 is an 11/70 without FP11, with RH disk controller and DEUNA. It has it’s console on the serial port (9600/8/n/1) instead of the embedded terminal, and has the (almost) original M9312 boot code instead of my own ‘old’ boot code.

The board does not usually power up in a reset state; press the BTND button to manually reset it.