BBC Model B implementatation for myStorm BlackIce

disneysw 2017-09-30 21:47:26 UTC #61

Check out the 0xED (Set/Reset LEDs) command in this description of the PS2 keyboard protocol if you want to know how to control the keyboard LED's:

http://www.computer-engineering.org/ps2keyboard/

tony1tf 2017-10-04 08:26:05 UTC #62

You will see from an earlier posting that @hoglet is using the BlackIce pin definitions, not the PMOD ones. This causes immediate confusion, and it was a coincidence that his pin 9 is next to PMOD pin 8.

noggin 2017-10-13 18:15:27 UTC #63

Managed to get the BBC Model B emulator to work after an hour or two of reading and careful installation.

Using Windows 7 I had to use the Zadig method to get my MyStorm to be recognised by dfu-util in Windows. Flashing the .raw file was then straightforward.

Initially my 23" LG TV with VGA input wouldn't accept a 50Hz input, but a £9.99 Amazon VGA to HDMI Converter (which will also inject stereo audio from a 3.5mm jack) I had kicking around converted the 15.625kHz SRGB to HDMI in a format that the monitor would accept.

First two keyboards I tried with proper PS2 connectors (cheap no-name mini keyboard and a genuine IBM Model M from a genuine PS2) didn't work. 10 year old Microsoft USB Media Keyboard with a purple USB to PS2 converter worked fine.

My Sony UHD TV and Denon AVR don't like the output of the VGA to HDMI converter, but I also have a Composite/SCART/HDMI to HDMI converter (for frame rate conversion, audio extraction etc.) and that converts the 576p50 signal it thinks it is getting to 1080p50 that the AVR and TV are happy with.

It's not perfect - the Mode 7 interlacing is a bit funky - but until I get a VGA->SCART cable it's fine!

For info I'm using proper Digilent VGA and PS2 PMOD boards. Just need to build a little audio cable to header.

Very happy bunny!

codepope 2017-10-15 16:38:28 UTC #64

Getting there putting this together. Diglent VGA and PS2 mod.

My issue is the keyboard. Tried a couple now, with and without 5V on the Diglent PS2 pmod power pin and, so far, no response (apart from occasionally booting up and getting a ghost return clicked every minute or so... spooky)...

Any tips on how to push on and identify the problem? Any pins I can prod the see if a signal is generated and or getting through?

hoglet 2017-10-15 16:55:59 UTC #65

Do you have access to a scope or a cheap logic analyzer?

If so, you should probe the pins marked C1 and D1 on the PS2 PMOD.

When a key is pressed you should see a short burst of clock pulses on C1, and a key code on D1.

There are some diagrams showing what to expect on this page:
http://www.computer-engineering.org/ps2protocol/

The PS/2 interface in BeebFPGA is rather basic, and (as far as I remember) is input only. If the keyboard needs any kind of packet to wake it up, that might be a problem.

agould 2017-10-16 06:41:30 UTC #66

I had a similar problem to this but when I applied the logic analyser I saw that I was getting a left shift key sent every 500ms and that's a''. Not sure if that was just a broken keyboard. In the end I got a used HP PS/2 keyboard from EBay and that worked just fine.

codepope 2017-10-16 20:33:06 UTC #67

Probe applied (well an Aeroscope) and no, doesn't look like there's life.

Alternate keyboard plan time methinks.

codepope 2017-10-16 20:33:44 UTC #68

I think thats what I will do. You wouldn't have a model number on yours for me to search on?

agould 2017-10-17 16:27:24 UTC #69

The model number I have is KB-0316

codepope 2017-10-20 09:13:11 UTC #70

And success... now with a Microsoft RT2300 keyboard (Surfboard for surfing the web) PS/2 version, we have a Hello World.

Now to figure out why I can't load things from the MMB sample...

hoglet 2017-10-20 17:36:01 UTC #71

What's the exact error message you are seeing?

codepope 2017-10-20 17:52:38 UTC #72

Listings of the games appear. Select one and I get File Not Found. Press Space to return to menu,

Initially suspected it was down to the big FAT32 16GB stick I was using, now on 8GB but same thing.

hoglet 2017-10-20 18:10:53 UTC #73

That does sound like the MMB image I posted might be faulty.

Can you try this one instead:
https://github.com/hoglet67/Ice40Beeb/releases/download/release_1/BEEB.MMB2.zip

codepope 2017-10-20 18:45:14 UTC #74

Yay! Works! Thankee kindly!

hoglet 2017-10-20 18:59:02 UTC #75

Great, I'll replace the old one then.

Emuboy 2017-11-04 17:16:36 UTC #76

Hey @hoglet , thanks for the great job you did with the been code , I build myself a ps/2 adapter and I noticed that using a logic level shifter increase dramatically the keyboard compatibility , sadly , with my screen the image is flickering a lot , I think is a frequency problem , I noticed you recently put a scan doubler in but I haven't found a way to enable it , am I missing something? Thanks!

hoglet 2017-11-04 17:44:02 UTC #77

It defaults to VGA mode. You should be able to enable sRGB mode by holding SW4 down for 1 second.

Emuboy 2017-11-17 15:02:21 UTC #78

Is supposed to flicker a lot ? I'm trying it on many monitor, LCD, crt , TV and on all of them is very flickery , is it because of the approximation due to the pll ?

hoglet 2017-11-17 15:30:45 UTC #79

No, it's not.

But your monitor / TV needs to support 50Hz vsync. And not many LCD monitors do.

Your best bet is a TV with an RGB Scart, and then use sRGB mode.

Are you in the UK?

Can you list the models numbers of the devices you have tried, and say how you have connected to the?

Dave

Emuboy 2017-11-17 20:01:06 UTC #80

Yes, I'm in the UK , at the moment I'm testing it on :

CRT:
sony PVM 1440Q (rgb)
Mitsubishi DiamonPro 750SB (vga)
random Samsung 14" crt tv
LG LCD
Acer LCD
Samsung LCD

the flickering is very noticeable, and I'm used to crt , and the pvm is usually a stable rock with the signal...