https://www.youtube.com/watch?v=wW1th462IKM

root42 does it again ? 😀 lets wait

root42 Hey everyone! Soooo sorry. I botched it. I will have to do the stream tomorrow.
root42​I put in the wrong date in my YouTube and my personal calendar. Sorry guys and gals!

Stream tomorrow!

Revision Update:

i don`t think it makes sense to make Quad DAC just use two Dual Cards and mix Outputs.
There is really only one Program Supporting it 😀

Now Mono Playback on LPT Adresses, Stereo on different.
Still have to choose "hopefully" Conflict Free Adresses, any Suggestions here ?

matze79 wrote on 2020-11-22, 17:11:

Still have to choose "hopefully" Conflict Free Adresses, any Suggestions here ?

Consider 16-bit address decoding - this would allow addresses like 378h+400h, 378h+800h, 378h+C00h, and so on...

Or: Use 16 bit port writes. I.e. 378h+379h to be able to write both L and R samples with one 16 bit out instruction.

BTW, I've found a special LPT card which can be set for both standard and non-standard addresses:
3BC
378
278
268
27C
26C

@matze79 A bit of topic perhaps, but can you perhaps share the workflow you use to get such high quality visual renders of KiCad designs?

Recently I rendered a 3D image of a KiCad design of another project (using the example instructions found at Hackaday), and importing into Blender and such proved quite a hassle. I eventually got it to import properly, but I didn't even come close to getting the quality that you got, because I skipped on a lot of the suggested tweaks described in the guide at Hackaday. Perhaps you found a more automated script somewhere that can do this for you? Or are you just very experienced and proficient with Blender (or other 3D rendering tools)?

Thanks. 🙂

You just have to change the 3D Preview to ray tracing.
It’s part of Kicad.

https://kicad.org/discover/3dviewer/

matze79 wrote on 2020-11-23, 23:28:

You just have to change the 3D Preview to ray tracing.
It’s part of Kicad.

https://kicad.org/discover/3dviewer/

Ach so! 😅 I've played with the 3D preview before and I wasn't impressed with the quality, but I didn't know it also had an actual high-quality ray tracing option. I should have examined all the bells and whistles of KiCad better. Thanks!

Grzyb wrote on 2020-11-23, 23:15:

BTW, I've found a special LPT card which can be set for both standard and non-standard addresses: 3BC 378 278 268 27C 26C […]
Show full quote

BTW, I've found a special LPT card which can be set for both standard and non-standard addresses:
3BC
378
278
268
27C
26C

3BC kinda was the original port address for LPT1..
It was hard-wired on Hercules compatible graphics cards (HGC, MGA)..
They also lacked an IRQ, not sure, speaking under correction here..
Anyway, never had an issue with it, except that some programs expect 378h as being the first parallel port.
Which it is, except if 3BC is in the system. Then 378h becomes LPT2..

Edit: http://wearcam.org/seatsale/programs/www.beyo … pp/parallel.htm

Jo22 wrote on 2020-11-25, 08:52:

3BC kinda was the original port address for LPT1..

Yes.
3BC, 378, 278 are standard addresses, supported by BIOS.
268, 27C, 26C are non-standard, but if somebody made an I/O card with these, they are also worth considering for similar projects.

It was hard-wired on Hercules compatible graphics cards (HGC, MGA)..
They also lacked an IRQ, not sure, speaking under correction here..

MDA uses IRQ7, but it's optional, and for many years no software used LPT IRQ.
That's why IRQ7 was the default in early Sound Blasters.
But then there came some OS/2 version with background printing - via IRQ, and that's why later Sound Blasters use IRQ5 by default.

How does a PC LPT detect ? does BIOS check for Status Registers to be present ?

matze79 wrote on 2020-11-25, 14:14:

How does a PC LPT detect ? does BIOS check for Status Registers to be present ?

According to Sergey Kiselev's implementation the BIOS just writes a test value to the LPT and reads it back. If that is succesful, it assumes a printer port at that address.

https://github.com/skiselev/8088_bios/blob/bb … rinter1.inc#L97

R1 arrived and works as expected 😀 looks bit ugly because of desoldered parts but! it works!
No longer flip switches for Mono / Stereo

My First PCB with KiCad