pi4 with pi4-gpio-clean not working

[Cid]

Hi everyone,

First, I'm sorry for all the questions those days, I really want my pidp8 to work.

So I have the pi4-gpio-clean branch installed on the latest raspian lite 32bits.

The pidp8i simulator is not working. It hang there.

Also I tried to install Deeper Thought 2, with the instructions from the Incadescent Thoughts, without success. The leds on the panel are lit up in a random pattern, but not blinking.

I saw the Post :

ERROR installing PiDP-8/I software on a Pi 4

 

And from my understanding, the issue is not resolve yet?

I feel there is multiple sources on how to install the simulator, some are new, other deprecated. Could someone point out which one is the one I should use specifically for a rpi4?

I had a rpi3 before, and everything was working perfectly, but a small accident kind of rip off the micro-usb connection from the board so it is unusable for now. Unless someone could tell me how I could access the GPIO power pin while the rpi is connected on the led panel?

Thank you and again I am sorry for all those questions!

[Heinz-Bernd Eggenstein]

The Raspi 4 is certainly "overkill" for the PiDP-8 , so using your mutilated Raspi 3 should be a nice solution: Powering it thru the 5V GPIO pin is no problem, and since you assembled the PiDP-8 kit already, I assume you are familiar with soldering. So all you need to do is feeding 5V and GND to any point on the PiDP-8 PCB that is directly connected to the respective Raspi pins.  If I read the schematics correctly the 5V pin from the Raspi header is connected to a diode on the PCB, so make sure you solder that new wire on the right side of the diode (the one connected to the raspi header).  The Raspi header pinout is like this :

https://pinout.xyz/#

(mind the orientation of the pinout as explained on that page, the pin opposite to the 5V pin is the 3.3V power rail, you don't want to mix them up......the 5V pin is the one next to the outer edge of the PI board at one of its corners... just saying...)

To make it pretty, you could use a cheap USB connector with solder pads or screw terminals so you have a nice connection for the power supply again, a la 

https://www.amazon.com/zdyCGTime-Connector-terminals-Pluggable-Cable%EF%BC%8830CM/dp/B07QPM24H3/ref=sr_1_3

(I am not recommending exactly this one, but you get the idea).

There are tons of stuff you can do with the Raspi 4 and they are difficult to get at the moment, so I'd give it a try to salvage the rpi3.

HB

[Cid]

Oops I just found out that "Reply to the author" is not public.

I was replying to HB that yes, I could solder wires on the board and make the rpi3 working again, but I wonder if it's less trouble than making the rpi4 working with the pidp8i. I could still use the rpi4 for other projects while it is driving the pipd8i.

[Steve Tockey]

Cid,

It would help to know what the PiDP-8/I front panel looks like when it hangs. Are there any lights on at all? If so, could you snap a photo and post it? The question to answer is, "How far into the SIMH initialization & OS/8 boot processes is it getting before it hangs?"

Further, when it does hang, what happens if you type Control/E on the PiDP-8/I console? Do you get the "sim>" prompt? or something else? or nothing?

[Cid]

So here is the message from the simulator, and the front panel leds that are on.

[Cid]

So based on the comments, I'll try to salvage my rpi3.

While looking at the board, I notice those pin (bottom right on the picture). Could I use those to power the pi and the board?

I try to look at the traces under the silkscreen and it does look like it goes to the 5v pins on the rpi...

[Heinz-Bernd Eggenstein]

I can't remember seeing those on my PCB, I guess you have an older edition.... yes you can connect an external 5V power supply there, it's even documented on the build instruction page for the older version, see here : https://obsolescence.wixsite.com/obsolescence/copy-of-2016-pidp-8-building-instru  [sic]

HB

[Ian Schofield]

Dear Cedric,

 Is the light pattern we see above what happens? If so, this is a bit odd. It looks like the OS/8 boot has gone wrong. And, although the run light is off, the simulator has not stopped.

 I suggest you run the test light/switches stuff and see if this bit works.

 And, as Steve suggests, type ctrl-e into the console and send the result.

Regards, Ian.

[Cid]

Yes, later yesterday evening I went to see the documentation. That's what I will do.

Thank you

[Cid]

About the light pattern, I did the test and everything goes well beside the switch test, and from what I read here, it seems that I'm not the only one having this issue with the Rpi4. But I can say that the test is successful on a Rpi3.

About the Ctrl-E message, I'm not home for the weekend, but I can say that it doesn't work, nothing happen. I have to do Ctrl-C, which will give me a message about loading RK05, but then again, nothing happen. If then I do Ctrl-E, it exit and I have a "sim" prompt.

[Steve Tockey]

According to my tests, as SIMH is starting up it sets address 0100 into the Program Counter, so it appears that your SIMH is coming up normally. My guess is that the problem could be in your  boot file:

/opt/pidp8i/share/boot/0.script

One experiment would be to try to boot the PiDP-8/i with a different bit pattern in the Inst Field switches. For example, IF = 2 (010 binary) tries to boot up TSS/8. IF = 3 (011 binary) tries to boot up OS/8 on simulated DecTape. IF = 6 (110 binary) tries to boot up ETOS. If any of these successfully boot then the problem would seem to be in the 0.script file. If so, you should be able to find the original 0.script file in, for example:

/home/pi/pidp8i/boot/

Somewhere in your home/pi/ directory will be the PiDP-8/i simulator source code that you downloaded and decompressed. Within that directory tree will be the /boot/ directory. If the problem is a corrupted 0.script file, copying from the /home/pi/ ... /boot/0.script into /opt/pidp8i/share/boot/0.script would  restore you to the original, working 0.script file.

I hope this helps,

-- steve