PDP-11/70 CPU core and SoC :: Overview
Other project properties
Fig D-1: A PDP-11/70 Console. These display and switch consoles were the hallmark of the PDP-11 computers in the 70ties. Picture courtesy of Henk Gooijen, see also Henk's PDP-11 collection.
This is a retrocomputing project, rebuilding hardware and running software from the late 70s and early 80s. To get into the tune see Figure D-1, a 11/70 console, and Figure F-2, a baseline system setup.News 2014-08-10: Release w11a_v0.61 available for details see section Releases.
News 2014-06-19: doxygen generated code browsing available for vhdl and C++ sources. No documentation text added so far, but helpful to navigate through the code. Good starting points are vhdl module list, or sys_w11a_n3 source, or C++ class list .
For more details see the sections:
Running SystemsThe project holds all the sources to synthesize a complete system. Complete configurations for three boards are currently part of the project, the Digilent S3BOARD, Nexys2 and Nexys3 boards. See section Features: Complete Systems for details.
So far two UNIX systems have been successfully booted on the w11a:
- UNIX 5th edition
- 2.11 BSD UNIX
Known IssuesThere are some known difference between w11a and 11/70 and also known bugs in the current w11a implementation (see w11a_known_issues.txt). They affect the behaviour in cases like fatal stack errors or certain double faults which don't occur in the normal operation of an operating system, and if they happen, in general lead to a crash anyway.
The known differences are not considered worth fixing them, while the known bugs will be addressed in future versions of the w11a core.Given that the w11a boots 2.11BSD the cores are considered 'Design Done' and 'FPGA proven'. The USB based Rlink interface and the backend software perform very well. Given the loose ends listed above the project is still considered 'Beta' quality.
Being a 'leisture time project' things evolve at a modest pace. Key milestone so far were:
|•||Apr-2013:||new C++/Tcl backend server, w11a designs operate with rlink over USB|
|•||Jan-2012:||Cypress FX2 USB controller support added, rlink and config over USB.|
|•||Dec-2011:||Spartan-6 port of w11a added (for Digilent Nexys3 board).|
|•||Jul-2010:||OpenCores project w11 created; w11a V0.5 tagged and released.|
|•||May-2010:||w11a systems ported to Digilent Nexys2 board; lots of cleanup.|
|•||Sep-2009:||2.11BSD UNIX boots to multi-user mode on w11a on FPGA.|
|•||Aug-2009:||UNIX 5th Edition boots on w11a on FPGA.|
|•||Jun-2009:||Found 11/70MP system manual on bitsavers. Most of IIST implemented. Too early, but fun.|
|•||Dec-2008:||Finished the last of three 2.11BSD patches, now 2.11BSD boots of a RK05 disk set and runs on a 11/70 without FPP in simh.|
|•||Mar-2008:||Full system with CPU, cache, and minimal I/O system runs on FPGA.|
|•||Sep-2007:||rri (rbus+rlink) implemented, w11a runs on FPGA (Digilent S3BOARD).|
|•||Sep-2006:||CPU and MMU implemented, simple test codes run.|
|•||Jun-2006:||Re-discovered a pile of PDP-11 manuals in a forgotten box full of old paper work. This triggered the idea, and with simh, ghdl and bitsavers at hand, 2.11BSD as target OS and a 11/74 picture as desktop background it quickly became a project.|
Major releases are tagged on svn, minor releases are denoted only via the svn revision.
|Release||Date||svn tag||svn rev||README||Comment|
|w11a_V0.61||2014-08-10||w11a_V0.61||25||README||Bugfix for DIV instruction (see ECO-026-div); other minor fixes|
|w11a_V0.6||2014-06-06||w11a_V0.6||23||README||from 0.5 -> 0.6: revised ibus and rbus protocol; backend server rewritten; Nexys3 port; Cypress Fx2 support; LP11,PC11 support|
|w11a_V0.581||2014-05-29||-||22||README||Fixes for ISE 14.7; Spartan-6 CMT support; more man pages|
|w11a_V0.58||2013-05-12||-||21||README||LP11,PC11 support added; old backend retired; operating system kits re-organized|
|w11a_V0.57||2013-04-27||-||20||README||w11a systems with rlink over USB on nexsy2 and nexsy3 boards|
|w11a_V0.562||2013-04-13||-||19||README||Phase 2 of new C++/Tcl backend, add cpu and first device support; add asm-11 assembler|
|w11a_V0.561||2013-01-06||-||18||README||Add bugfixes, Cypress FX2 simulation model, and test designs for Nexys3 and Atlys boards|
|w11a_V0.56||2013-01-02||-||17||README||Add Cypress FX2 USB interface controller; FX2 firmware supporting jtag access and data transfer; test system for rlink over USB verification|
|w11a_V0.55||2011-12-23||-||16||README||Add xon/xoff (software flow control) support to serport library; Add test design for serport verification|
|w11a_V0.54||2011-12-04||-||15||README||Add Nexys3 port of w11a|
|w11a_V0.532||2011-11-20||-||14||README||Add test design for 'human I/O' interface; migrate to use numeric_std|
|w11a_V0.531||2011-09-12||-||12||README||Prepare upcoming support for Spartan-6 (nexys3 and atlys) and Cypress FX2 USB (nexys2/3 and atlys)|
|w11a_V0.53||2011-04-17||-||11||README||Introduced new backend written in C++ and Tcl. Phase 1 with functionality to execute simple test benches|
|w11a_V0.52||2011-01-02||-||9||README||Introduced rbus protocol V3; reorganize rbus and rlink modules, many renames|
|w11a_V0.51||2010-11-28||-||8||README||Introduced ibus protocol V2; Nexys2 systems use DCM; sys_w11a_n2 now runs with 58 MHz|
|w11a_V0.5||2010-07-23||w11a_V0.5||-||README||Initial release: w11a CPU core; basic set of peripherals: kw11l, dl11, lp11, pc11, rk11/rk05; two complete systems for Digilent S3BOARD and Nexys2|