Weeknight 'Virtual' Dev session #9, Thursday 14th January 2021, 7pm - 10pm (GMT)

[Pernod]

I'll try to pop in when I can.

[kieranhj]

Hi all, I hope the CRTC Register Masterclass session was helpful for people and apologies again for the interruption halfway through! I've sent Arcadian the PDF version of the slides to upload alongside the video when it eventually arrives. In the meantime, these are the two demo programs in BASIC:

• 6845 Register Browser
• Hardware Scrolling

Feel free to hack away to your heart's content and please send any 6845 related questions, I'll be happy to answer them.

[BigEd]

Thanks! That register explorer looked really handy.

[tricky]

Anyone fancy giving us a quick into to https://www.raspberrypi.org/blog/raspbe ... w-on-sale/ at one of the dev nights?
And explain why when the beeb and the chip have 4 analogue inputs, only three are exposed Voltage sensing or temperature maybe?

[dp11]

I could do that . The forth ADC channel does indeed monitor the PSU. But if you are happy with a soldering iron removing a resistor and adding a wire gives you back the ADC channel. I have already ported the Fast PiTubeDirect 6502 core to the RP2040.

[tricky]

I noticed that there are many versions of it, but not one with 5V level shifters built in

PS I'm sure there are others, but it does seem like a good halfway house between a PiZero and a PICxxx.

PPS I thought that you might be able to help

[dp11]

This is now public : https://twitter.com/Raspberry_Pi/status ... 9768411136 (not my work)

[hoglet]

This is now public : https://twitter.com/Raspberry_Pi/status ... 9768411136 (not my work)

Oh lordy, that is impressive!

Is the board shown on the video the VGA Demo Base Board?
https://shop.pimoroni.com/products/pimo ... -demo-base

Dave

[BigEd]

We need a mini-talk on how that cycle-accurate beeb emulation manages its performance!

[dp11]

This is now public : https://twitter.com/Raspberry_Pi/status ... 9768411136 (not my work)

Oh lordy, that is impressive!

Is the board shown on the video the VGA Demo Base Board?
https://shop.pimoroni.com/products/pimo ... -demo-base

Dave

Its our minimal VGA board I think, KiCad files are on the Raspberry website

[Arcadian]

Any takers for presenter/update slots at this week's Dev night?

dp11 you good to overview the Pi Pico?

[dp11]

I can do.

[dudleysoft71]

I've got a new project, I could do a slot about it.

[Revaldinho]

@Arcadian - room for another at the next dev meeting please ?

Rich

[Arcadian]

@Arcadian - room for another at the next dev meeting please ?

Rich

invite sent!

[Arcadian]

I've got a new project, I could do a slot about it.

Yes please! Shall I slot you in for half an hour from 8?

[dudleysoft71]

I've got a new project, I could do a slot about it.

Yes please! Shall I slot you in for half an hour from 8?

Yeah, that will be fine, should give me time to show off what I've been working on.

[IanS]

Wouldn't this thread be a better place to be discussing things? viewtopic.php?f=25&t=21498

I'd like an invite, will try and join later on.

[Arcadian]

Wouldn't this thread be a better place to be discussing things? viewtopic.php?f=25&t=21498

I'd like an invite, will try and join later on.

I've issued the invite (which I can see you've already accepted) and have added you to the default invitee list for all events, hope that's ok - let me know if otherwise.

Yes, all discussion re: tomorrow's Dev Night in the correct thread from now on please!

[Arcadian]

Kieran's masterclass video from the evening is now online:
An introduction to CRTC Registers on the BBC Micro - Part One

http://abug.org.uk/index.php/2021/01/14/bbc-micro-crtc-registers-part-1

Topics covered:

1. What can we do with the CRTC registers?
2. What is the CRTC responsible for?
3. 6845 CRTC display generation
4. 6845 CRTC Registers
5. 6845 registers mapped onto the display
6. 6845 registers for MODE 0/1/2 display
7. Programming the 6845
8. Display start address R12/R13
9. Hardware scrolling
10. What happens above &8000?

To discuss this, and to download the supporting presentation, please visit this thread.

[Steve B]

Great video - relatively easy to follow. I'm looking forward to part 2 .