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Forum Index : Microcontroller and PC projects : Got a spare Pico? Build a Macintosh....

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gadgetjack
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Joined: 15/07/2016
Location: United States
Posts: 158
Posted: 02:45am 26 Nov 2024
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I read a comment a bit back that there were no good emulators for the Pico. I just built this from a new file on github called a Pico-Mac (or pico-micro-mac). It boots to a black and white screen of a macintosh 128k from about the 1985 era. It loads a 30 meg "hard drive" from the sd card. It plays games , does the paint program , and about everything else that old machine did. I got the re-compiled program that lets you use 208K for the machine (thats all you can get from a stock pico). Not a great machine but a good way to pass time for us old retired guys. It outputs in VGA and uses a regular mouse of the usb type. If you have trouble getting the files to compile ( like me ) , i can send the files in a zip. I will write what is in the file so it won't get deleted.
LOL like last time.....
Jack
 
Frank N. Furter
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Joined: 28/05/2012
Location: Germany
Posts: 910
Posted: 08:02am 26 Nov 2024
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Very cool! Thanks for sharing!      

Frank
 
Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 7151
Posted: 08:05am 26 Nov 2024
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I like. :)
I suspect it's not that different in speed either. It may even be a bit quicker. Could you get more RAM using a Pico 2?
Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs
 
Frank N. Furter
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Joined: 28/05/2012
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Posted: 09:11am 26 Nov 2024
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I would be very interested in the compiled files! What kind of display did you use?

Frank
Edited 2024-11-26 19:12 by Frank N. Furter
 
gadgetjack
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Joined: 15/07/2016
Location: United States
Posts: 158
Posted: 06:02pm 26 Nov 2024
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Frank,  I used an old car backup monitor that had a vga input. Not a great picture but it was small enough to put in a case. Any vga monitor will work. The zip has files for pico and pico2 , the readme, and the file for the sd card to have a "harddrive". Lots of old games and stuff. Have fun!!
Jack

firmwareSDpico2.zip
 
gadgetjack
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Posted: 06:05pm 26 Nov 2024
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Mick , the author is working on adding more ram with the pico2 but it is not yet ready.
This file gives 208k working.
 
Mixtel90

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Posted: 06:26pm 26 Nov 2024
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Thanks, Jack. :)
Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs
 
Frank N. Furter
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Joined: 28/05/2012
Location: Germany
Posts: 910
Posted: 07:41am 27 Nov 2024
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@gadgetjack:

Thank you very much!

Frank
 
Volhout
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Joined: 05/03/2018
Location: Netherlands
Posts: 4562
Posted: 08:02am 27 Nov 2024
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  Mixtel90 said  I like. :)
I suspect it's not that different in speed either. It may even be a bit quicker. Could you get more RAM using a Pico 2?


If you see the DEMO video that is in the uMAC site, it is plenty quick. Near unplayable games. But maybe that is not the last release. Making it slower is always sooo easy.

GadgetJack, thanks for providing the ZIP. I went the the uMAC website to find the wiring of the VGA. They drive RGB parallel from one GPIO with 100 ohm series. That may work but exceeds the max current for GPIO pins by far...

Volhout
Edited 2024-11-27 18:05 by Volhout
PicomiteVGA PETSCII ROBOTS
 
gadgetjack
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Joined: 15/07/2016
Location: United States
Posts: 158
Posted: 05:04pm 27 Nov 2024
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I made mine with 3 100 ohm resistors , one on each line. Kind of thought , better safe than sorry.
 
phil99

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Joined: 11/02/2018
Location: Australia
Posts: 2301
Posted: 08:45pm 27 Nov 2024
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  Quote  3 100 ohm resistors , one on each line
That will overload the Pico pin even more. Expect a short life.

The minimum safe load resistance for any Pico output pin is about 220Ω, which can drive just one VGA input.

To drive 3 VGA pins requires 28mA, that is way above the safe limit so you need a transistor emitter follower to provide the extra current. The emitter resistor should be 68Ω to 75Ω going to all 3 VGA paralleled inputs.
The collector can be connected to 5V and the base directly to the output pin.
Edited 2024-11-28 07:39 by phil99
 
Martin H.

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Joined: 04/06/2022
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Posted: 12:29pm 18 Jan 2025
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a project for cold winter days
Flying wiring but it works.
Unfortunately I have not yet managed to enlarge the image section


'no comment
 
gadgetjack
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Posted: 02:03pm 18 Jan 2025
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If you can compile code on a Linux machine, the author has fixed the screen size problem. It now fills the screen. I have trouble compiling it myself. Only got windows machines.
 
Martin H.

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Joined: 04/06/2022
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Posted: 04:56pm 18 Jan 2025
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me to, so i am not able to recompile
also it would be nice to use 256 KB Ram on the Pico 2
'no comment
 
Frank N. Furter
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Joined: 28/05/2012
Location: Germany
Posts: 910
Posted: 12:31pm 31 Jan 2025
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@gadgetjack:

Do you have a link to the sources for me?

Frank
 
gadgetjack
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Joined: 15/07/2016
Location: United States
Posts: 158
Posted: 05:24pm 31 Jan 2025
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https://github.com/evansm7/pico-mac
 
gadgetjack
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Joined: 15/07/2016
Location: United States
Posts: 158
Posted: 06:53pm 31 Jan 2025
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Frank , if you get the full screen version compiled , I would love a copy of the uf2. Make sure to use the 208k ram option or most programs will fail from lack of memory.
Thanks.
Jack
 
Frank N. Furter
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Joined: 28/05/2012
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Posts: 910
Posted: 08:46am 03 Feb 2025
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@gadgetjack:

Thanks for the link - I'll ask a buddy if he can compile it. If it works, you will of course get a UF2 from me!

Frank
 
gadgetjack
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Location: United States
Posts: 158
Posted: 10:31pm 03 Feb 2025
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Thanks Frank. I bought a blank pc board for the project the first time and got a copy of the software as of that date , but it has gotten better since then. I tried again on a laptop with Ubuntu installed , but no joy. I don't know enough about Linux to keep going.
Jack
 
gadgetjack
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Joined: 15/07/2016
Location: United States
Posts: 158
Posted: 02:05am 07 Feb 2025
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Had a friend compile this for me on Linux. It has full screen 640x480 so fills the monitor. Has the 208k memory also. I have not loaded it yet on my system but I trust my friend so here is a copy to try.
firmware.zip
Jack
 
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