uTracer11 architecture allows also to use the GUI for a PDP-11 simulation (in contrast to a physical machine) .
Connection to the GUI is over a TCP/IP lowel socket interface then.
To be useful, the simulation must truly reproduce the
- CPU micro machine
- main memory
- and some aspects of UNIBUS access
On the plus side, a simulator can expose more CPU internal registers than a physical PDP-11.
This means: neither over the KY11 panels, nor with the KM11 adapters can you examine internal stuff like ALU A&B legs, BX, AMUX, IR or SSMUX flip flops inside CPU control and Datapath.
But a simulator can tell the GUI any list of variables to show!
Triple Interfaces
A PDP-11 simulator (like SimH) usally has usually two "console" interfaces.
1. the "Simulator console" , a text window to control operation of the simulator itself. Typically its used for device configuration (how much memory do I want? Which disk drive to use and what images to mount?), and to boot/halt/stop/reset the simulated machine.
2. the "Operators console" of the simulated machine ... for PDP-11 this is the character I/O stream connected to the first "DL11" serial card.
It is used to manage the simulated machine after the simulator started executing it.
Simulator and Operator console may or may not share the same window on your Windows/Linux GUI, or they may both be routed to different or the same telnet/ssh connection ... confusion ahead.
3. A uTracer11 simulator needs to implement another interface: the probe which monitors the operation of the internal guts, the simulated micro machine.
This is a TCP/IP socket connection receiving and responding the uTracer11 Message Interface.
The recommended default socket number is 65392, the decimal PDP-11 console DL11 base address of octal 177560.
This message interface is in fact the implementation of a CPU diagnostic port, like PDP11/34 KY11LB, or the KM11 FlipChip sockets on other CPUs.
The other side of this TCP/IP socket is the "uTracer11 GUI", which makes the nice visualizations and micro machine control.
And: as the Message Interface transfers plain text ASCII strings, you can also connect with a regular telnet client to the message socket and type/receive uTracer11 messages to the simulator. This is no fun, but can be used for testing.
<bild: telnet>
Operating
start command line
command line GUI
GUIless via putty telnet
Implmenation: what to implment for the message protocoll