Design #3 - PicoMite VGA mini


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Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 6847
Posted: 03:55pm 04 Apr 2023      

I know it works on mine because I've just been using it. :)
As Peter says, you need the full level shifter circuit. That's Q1, Q2, R6, R7,R8 and R9.

Are you able to get the Num Loxk and Caps Lock LEDs to work on the keyboard? If they are working then it has a supply and its on-board controller is running.

Also, check for solder whiskers around the PS2 socket and pins 11 and 12 (GP8 and GP9) of the PicoMite.

lizby
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Joined: 17/05/2016
Location: United States
Posts: 3159
Posted: 04:05pm 04 Apr 2023      

I definitely have the 4 10K resistors R6, 7, 8, & 9. The only resistors I don't have are R4 and R5, since I expect to try the SCL & SCK lines with non-I2C devices, and if I use I2C modules later, they will have the pullups on board.

As I say, I don't know that this keyboard works. I will be getting another one to try.

Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 6847
Posted: 05:45pm 04 Apr 2023      

Ok. Let us know how you get on.  :)

lizby
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Joined: 17/05/2016
Location: United States
Posts: 3159
Posted: 02:00pm 05 Apr 2023      

I got an HP PS/2 keyboard from Habitat for Humanity for $5 and it works.

Now, what are some programs which show off the graphics ability of the PicoMiteVGA?

Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 6847
Posted: 06:12pm 05 Apr 2023      

That's a very good question. There is no definitive list that I know of - and my programming skills aren't all that good, I'm afraid, so I haven't written any.  :)

thwill

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Joined: 16/09/2019
Location: United Kingdom
Posts: 4049
Posted: 08:21pm 05 Apr 2023      

You might find something in the "Interesting programs" section of my ad-hoc list: https://github.com/thwill1000/cmm2-sptools/wiki - everyone feel free to let me know of things I've missed.

Or there is my Lazer Cycle game: https://github.com/thwill1000/mmbasic-lazer-cycle

Best wishes,

Tom

Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 6847
Posted: 12:53pm 15 Apr 2023      

The Constructors Pack has been updated.
Briefly:
The original version is now PCB version 1.3
Version 1.2A is now PCB version 2.3
The circuit diagram has had some textual changes.
The manual has had a few changes.

This was because I discovered, while messing about with ELIZA in colour, that I had Red and Blue video signals reversed. Easy enough to fix (explained in the manual) but annoying. This has been fixed now.

I've been using this for a while now and that's the only major problem I've found.

Geoff, if you read this, please let me know if there is any more info that you'd like.