A 2nd version of QProbe is more "Blinkenlighty" now.
A video explains the new board in action:
How to get
Business stuff first:
QProbe2023 is in its prototyping stage yet, but it can be ordered in advance.
The base board is €100, the "LED-Plug" is €65, the "Drive-Bay-Panel" is €80.
If you want it prebuild and tested, add €150 ... (so much to solder!).
The "2023" version has some enhancements:
- LEDs are now separate from the main PCB.
This allows either for remote-mounted Blinkenlight units, which are not hidden inside the PDP-11 case.
Also design of further Light&Switch consoles is much easier.
(And it drives manufacturing costs.)
- QProbe2023 can also drive QBUS signals: BRPLY, BHALT, BDCOK and BEVENT.
This allows implementation of QBUS control registers, as well as implementing the switches for RESTART, HALT and DISABLE LTC.
- Termination resistors for BDAL<21:18> can be switched off separately.
This is important for the LSI11/03 M7264 CPU module, which puts some internal microcode signals onto these wires.
As before, theres a large area dedicated to connect a Logic Anayzer to the QBUS. However, this is considered "optional" ... once your PDP-11 is running, Blinkenlights are most important.
Blinkenlight option 1: "LED-Plug"
This is the dual-LED row from before, plugged onto QProbe via long connectors.
It is most simple to build, as the LEDs are mounted in a regular way: no complicated 90-degree 3D-print assembly required.
Blinkenlight option 2:"Drive-Bay-Panel"
This panel mounts into the 5-25" drive bay of a BA23 case, for example.
The design is that of an 1970s PDP-10/12/15 rack header panel:
So it's definitely not really a "restauration", more a retro-insider-joke: a 1960/70ths 19" panel in a 1980/90th BA23 case!
Beside, there are now two switch blocks:
"Operator" are the 3 switches on LSI11/03 resp. 11/23 cases:
QProbe2023 implements the PDP-11 Display Register at 777570, whose content is visible on UNIBUS Blinkenlight panels, but not implemented on any QBUS machine.
Now it is.
Display Register is write-only, the corresponding Switch-Register on same address is not present.
Display Register is present in all modes, expect 0001. This means QProbe responds properly to a DATO cycle to IO adddress ...7570, actively pulsing BRPLY.
QProbe has 4 switches, which modify behaviour of CPLD logic. They are used to select several types of display or test options. Currently we have:
0000: Regular Display: ADDRESS/DATA are demuxed by SYNC and show on apprioriated LED rows. Short pulsing signals like IRQ or DMA are enlongated so they are visibile to the human eye.
0001: "Fully passive". QBUS signals are put onto LEDs unprocessed. ADDRESS is BDAL, DATA not used.
Display Register is NOT implemented in this mode. Useful for static checkout of backplanes
0010: "Test Mode", LED test. Like 0001, but DATA shows a copy of ADDRESS, and Display Regsiter. Used for LED test after assembly.
0011: Same as 0000, but detection of CPU HALT and signal generation on pin LA. CPU stop is recognized when microcode ODT access UART at 777560 without interwoven opcode fetches.
0100: Show "Display Register" content on DATA LEDs.
Other ideas for "Mode" include:
- A pulsing bargraph showing IRQ/DMA load.
- Force/suppress longer display of IRQ and DMA pulses.
- Route some QProbe LA signal inputs to some LEDs. This way other signals from the PDP-11 guts may get visible.eas, but limited by my Verilog capabilities ...