Search found 2367 matches

by Dave
Tue Jun 18, 2019 9:36 pm
Forum: Software & Programming
Topic: Announcing availability of a QLNET driver for the Q68 (ND-Q68)
Replies: 31
Views: 747

Re: Announcing availability of a QLNET driver for the Q68 (ND-Q68)

That is the exact header I have. Some have the index key, some do not. I decided to put the index key facing right, if present, because the other way it just touches the pins of the ethernet controller. The power connector is fine where it is, and the power switch is really a convenience item. Putti...
by Dave
Tue Jun 18, 2019 9:12 pm
Forum: Hardware
Topic: Symmetric multiprocessing...
Replies: 50
Views: 1966

Re: Symmetric multiprocessing...

That goes in the "asymmetric processing" thread, I think. In which case, I would point you to the CM3 version of the Pi, which has far superior GPIO. And they're the size of a laptop SIMM module. I hopefully will have something interesting to post photos of in a few weeks on that front.
by Dave
Tue Jun 18, 2019 8:37 pm
Forum: Hardware
Topic: Symmetric multiprocessing...
Replies: 50
Views: 1966

Re: Symmetric multiprocessing...

Absolutely they could. A larger FPGA would really be ideal for this. Peter's IP for the rest of the QL in FPGA would make it a home run. The limitation to overcome is the amount of internal RAM that can be structured as dual port. I'd propose throwing some discrete-made hardware out there first as p...
by Dave
Tue Jun 18, 2019 7:59 pm
Forum: Software & Programming
Topic: Announcing availability of a QLNET driver for the Q68 (ND-Q68)
Replies: 31
Views: 747

Re: Announcing availability of a QLNET driver for the Q68 (ND-Q68)

One thought - those 2mil pitch headers are more awkward to find connecting cables for than the more common 2.54mil pitch - could it work to include the 2mil (to connect to the Q68) and a 2.54mil for the pass-through connector? Like this? Screen Shot 2019-06-18 at 1.03.49 PM.png Screen Shot 2019-06-...
by Dave
Tue Jun 18, 2019 5:01 pm
Forum: Software & Programming
Topic: Announcing availability of a QLNET driver for the Q68 (ND-Q68)
Replies: 31
Views: 747

Re: Announcing availability of a QLNET driver for the Q68 (ND-Q68)

All the files are there if you'd like to do that. If a couple of other people request it also, I could add a second header on .1" pitch, and either could be fitted. The 2mm header was quite problematic. It is positioned too tight up against the RJ45 jack, so shrouded headers cannot be used. The...
by Dave
Tue Jun 18, 2019 4:29 pm
Forum: Software & Programming
Topic: Announcing availability of a QLNET driver for the Q68 (ND-Q68)
Replies: 31
Views: 747

Re: Announcing availability of a QLNET driver for the Q68 (ND-Q68)

In light of Peter's reassurances, I am releasing the following files under the standard open hardware license. This board implements two QLNET sockets, and has an extension bus through connector. I already have all the parts in stock, and will order the PCBs in the morning. Given the good number of ...
by Dave
Tue Jun 18, 2019 2:17 pm
Forum: Software & Programming
Topic: Announcing availability of a QLNET driver for the Q68 (ND-Q68)
Replies: 31
Views: 747

Re: Announcing availability of a QLNET driver for the Q68 (ND-Q68)

My solution would be to use a pair of BSS138 transistors to create a level shifter that would be high impedence if unpowered. How exactly would you wire them?[/quote] BSS138.png This is pretty much my standard level shifter. The only ugliness is grabbing 5V, but by removing the HV side power source...
by Dave
Tue Jun 18, 2019 1:51 pm
Forum: Hardware
Topic: Symmetric multiprocessing...
Replies: 50
Views: 1966

Re: Symmetric multiprocessing...

This is exactly how I would do it (still wondering why no attention seems to go toward FPGA for multiprocessing, where the CPU cores could be on a single chip and coupled very efficiently). I don't have your skills with FPGAs. Not even elementary skills. If I can get this functional with lean hardw...
by Dave
Mon Jun 17, 2019 8:28 pm
Forum: The Off-Topic Section
Topic: Today I Received...
Replies: 64
Views: 5333

Re: Today I Received...

That's a beauty. :D
by Dave
Mon Jun 17, 2019 7:50 pm
Forum: Software & Programming
Topic: Announcing availability of a QLNET driver for the Q68 (ND-Q68)
Replies: 31
Views: 747

Re: Announcing availability of a QLNET driver for the Q68 (ND-Q68)

I'm a bit concerned by the mod shown in the pdf. Its behavior is correct when the Q68 is powered, but if there is traffic on QLNET when the Q68 is unpowered, signal will still be passed to the FPGA regardless, plus try to power the Q68 through the diode. This would be problematic. Am I misreading it...