How old of a PC still makes sense to use?

Hey,

I glanced over the list of hardware on this site listing real-time compatible gear.
While I've even seen a Pentium II in there, I kinda doubt that current Ubuntu or Debian releases will run well on that alone, much less something like LinuxCNC on top, right?

I have a few old (parts of) PCs with LPT ports, none of which are ready to go as is.
So I wonder if any of those is worth repairing.

- Duron 600 (Nice aspect is: 230W PSU. Needs most repair, though)

- Athlon XP @ 1250MHz (can't boot from USB stick, takes some effort to get around)

- AMD64, 2 GHz (without case. *maybe* fits into one of the other 2 cases... Eats more power than the other options. (still significant compared to my small Chinese CNC router))

The most obvious seeming choice would be to use the most powerful CPU (if it actually passes the real-time test).
But maybe I'm wrong, maybe the older stuff is just fine, or even better with real-time for some reason (simpler, less fancy stuff on board?).
You tell me!

I got some decent results with an old P4 running linuxcnc under Slackware.

cncn00b2018 wrote: Hey,

I glanced over the list of hardware on this site listing real-time compatible gear.
While I've even seen a Pentium II in there, I kinda doubt that current Ubuntu or Debian releases will run well on that alone, much less something like LinuxCNC on top, right?

I have a few old (parts of) PCs with LPT ports, none of which are ready to go as is.
So I wonder if any of those is worth repairing.

- Duron 600 (Nice aspect is: 230W PSU. Needs most repair, though)

- Athlon XP @ 1250MHz (can't boot from USB stick, takes some effort to get around)

- AMD64, 2 GHz (without case. *maybe* fits into one of the other 2 cases... Eats more power than the other options. (still significant compared to my small Chinese CNC router))

The most obvious seeming choice would be to use the most powerful CPU (if it actually passes the real-time test).
But maybe I'm wrong, maybe the older stuff is just fine, or even better with real-time for some reason (simpler, less fancy stuff on board?).
You tell me!

I had an Athalon pc that wouldn't boot from usb or dvd only cd. It could read dvd's just not boot them which made it difficult to get the newer linuxcnc on the machine. I could have used another machine to install linuxcnc on the hard disk and swapped back into the Athalon but everything else I had was sata and this was IDE. Swapping hard disk's from one machine to another works fine I did it with a Sata drive.

I bought a coreduo on ebay for £10 and it gives very good latency scores which is ironic as I already bought a mesa because my I7 had terrible latency no matter what I tried then decided I'd rather run fusion 360 side by side with linuxcnc than dual boot.

All of them can be used for sure, so in order of appearance:
600MHz can be used with coolcnc iso (50 MB, works perfectly, but no updates)
1250Mhz can use DebianDog version of Linuxcnc (over 200 MB, again no updates or it will break )
2Ghz can run Wheezy and even Stretch but i would advise Wheezy.

Ok, as it sounds like it makes most sense to use the fastest machine, I put the 2 GHz dual core Athlon64 together.
Since the board apparently also cannot boot from USB (what the...) I burnt my last DVD I had laying around with the debian linuxCNC image.
It boots from DVD to the LinuxCNC screen where you can select some boot options, but that screen is frozen.
Any ideas what that could be?

Check the md5sum of the image before you burn it to DVD, and make sure you burn it at the lowest speed possible.

Ok it does boot from USB, just unlike DVD and floppy, it's not shown in BIOS setup if not present
Another DVD drive didn't read the image at all.
I did use the checksum, btw, ws ok.

So it boots from USB, I selected the first option in the menu, now there's a text screen displaying lots of messages, repeating that there's e.g. "Buffer I/O error on device sdb". Fail safe mode does the same.
So it can't read from the drive anymore, although it got to the menu at least?
What do I do with that info?

So now I just tried the option to install the thing with graphical mode.
After I selected the language, it took ages trying to detect CDROM drive. There is a DVDR installed and hey, it even booted" a little bit" from it as told above, but thaat didn't find it.
So it told me I could manually select the next steps of the installation.
Any they all are pparently based on getting stuff from CDROM.
But I booted from USB, what does it want with CDR? This doesn't work.
Now I'm really confused...

Do you have another working PC?
You just have a very old motherboard with old BIOS that has some known problems booting from USB, especially if it has any chipset other than NVIDIA.
Take the hard drive out from it and put it on another computer, preferably made after 2006, boot and install it normally, put the drive back on the computer that does not boot from USB and it should boot without problems.

Heh! Sounds too obvious, but as my linux experience is superficial and windows prior to w10 would be confused by such a drastic hardware change that this step didn't even occur to me as an option.

Although it could pose somewhat of a challenge, as the drive is some 160GB *IDE* drive (is that too slow for the overall task per se, or ok? It's what I had left over ), and I'd need another PC with IDE (need to look, not sure).

What I would have tried is to buy new DVDs, install winXP * on the machine in question , burn linuxCNC boot image from USB stick with that very PC's own DVD-writer, and hope that it could boot properly from its own produce
Your suggested way sounds like a higher chance of success, although also slightly messier, involving re-gutting another PC. Let's see.

Btw., the mainboard is this: www.asrock.com/mb/NVIDIA/ALiveNF6G-VSTA/
And then I have some cheap Radeon 9550, let's see how well that works. Probably better than with on-board gfx & shared memory (-> delays?).

Anway, thanks for your hints. And sorry if any frustration leaks from my comments, it's sometimes hard to hide I didn't expect this stuff to act up at this stage already.
I still don't understand why the setup is looking for "cdrom" at all, though.

By the way what is the PWM rate that can realistically be done via this LPT real-time kernel scheme? I saw somewhere 50kHz at most, but not sure I remember that or the context properly. The motors which came with my chinese 6040 CNC were spec'd at 200 kHz I believe. While I have some basic electronics knowledge, I'm not quite a motor expert, I don't understand whether this is a disadvantage or problem.

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* wanted that anyway as dual boot. After actually assembling the China CNC 6040, I can check the basic functrions using Mach3 demo, I guess. Best before I can no longer return stuff in case of problems, I have this lying around for a couple weeks already and not much time