New Open Source MultiCart released

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cheshirenoir
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New Open Source MultiCart released

Post by cheshirenoir » Thu Oct 08, 2020 2:47 am

Hey All,
Clockmeister and I are pleased to announce our latest version of the venerable MultiCart idea.
https://ilike8bits.wordpress.com/2020/1 ... on-system/
This one is released as a CC-SA-BY license so remixes can easily be done.
(Also if you are wondering what's going on with the resistors at the bottom of that board, I ordered the wrong resistor array, so I "faked it" with some normal resistors instead. Yes, I am an idiot sometimes. There's also a version of this board where I managed to select completely the wrong footprint.)
gandi12
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Re: New Open Source MultiCart released

Post by gandi12 » Thu Oct 08, 2020 12:52 pm

cheshirenoir wrote:
Thu Oct 08, 2020 2:47 am
Hey All,
Clockmeister and I are pleased to announce our latest version of the venerable MultiCart idea.
https://ilike8bits.wordpress.com/2020/1 ... on-system/
This one is released as a CC-SA-BY license so remixes can easily be done.
(Also if you are wondering what's going on with the resistors at the bottom of that board, I ordered the wrong resistor array, so I "faked it" with some normal resistors instead. Yes, I am an idiot sometimes. There's also a version of this board where I managed to select completely the wrong footprint.)
Perfect.
Looking foward to order it!
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cheshirenoir
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Re: New Open Source MultiCart released

Post by cheshirenoir » Fri Oct 09, 2020 4:52 am

Contact Clockmeister directly. I am sure he'll be able to help you. http://www.users.on.net/~clockmeister/
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MADrigal
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Re: New Open Source MultiCart released

Post by MADrigal » Fri Oct 09, 2020 11:32 pm

It is a lovely project! :) Congratulations!!! Love it!
Rastervision
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Re: New Open Source MultiCart released

Post by Rastervision » Sat Oct 17, 2020 11:34 pm

One suggestion would be to have "This side up" text.
I do see the pin 1 labeled. But, the board layout is different than a standard cartridge, which can lead to confusion.
Rastervision
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Re: New Open Source MultiCart released

Post by Rastervision » Sun Oct 18, 2020 1:07 am

She's a beaut.. no not the cartridge, my soldering skills. :lol:

The cartridge works nicely. I'm using a W29EE011 eeprom to allow quick testing of software.

Image

It even works with a game I am developing.
Image
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MADrigal
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Re: New Open Source MultiCart released

Post by MADrigal » Sun Oct 18, 2020 5:18 am

thats gorgeous! tell us more about the game you are developing!

one thing i have always wondered with all multicarts (including mine) is if there is a way to use the 32kb blocks 'straight' without having to invert the lower and higher 16k in the ROM bank. i assume it would be possible by using a slightly different logic on the PCB, eg switching the ROM1 and ROM2 pins. that would make it easier for game developers, too.
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cheshirenoir
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Re: New Open Source MultiCart released

Post by cheshirenoir » Tue Oct 20, 2020 4:12 am

Rastervision, thanks for sharing that. I'll do a revision with "THIS SIDE UP" on it shortly. Should be a quick fix :-)
Seeing Clockmeister and my work used like this... It makes me very happy.
I've also designed a shell for it but I'm a bit limited by my lack of actual 3D printer.
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cheshirenoir
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Re: New Open Source MultiCart released

Post by cheshirenoir » Tue Oct 20, 2020 4:44 am

MADrigal, Clockmeister and I wondered about that too. As all the files are there in KiCAD, that's an easy change to make. Next time I do an order I might try a "byteswapped" version and just do some experimenting. This was my main reason for the CC-BY-SA license we released it under. People can just make changes like that.
We stand on the shoulders of those who came before us. :-)
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Scouter3d
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Re: New Open Source MultiCart released

Post by Scouter3d » Tue Oct 20, 2020 8:05 am

Wow! looks so gorgeous in black!

I am still very "unsure" about the whole "ROM Bank swapping"
Please correct me if i am wrong:

the Creativision (in Hardware) has one continuous 32kb block of Space, that a ROM Cart can use as it pleases...

All the existing Carts use either only the upper part of that memory (irritatingly called ROM1) from $8000-$BFFF (this part is also completly free to use on the Laser2001/Salora Manager)
OR the also use part of the lower part (irritatingly called ROM2) from $4000-$7FFF (on Laser2001/Salora $4000-$5000 can not be used as it is also the mirror for the 1kb/4kb mirrored Systemram ($0000-$0FFF)

Up to16kb carts could use only ROM1 without any "bankswitching" (but many original carts use two ROM chips and use both ROM areas for simple Chipselect betwen the two (i guess cheaper) ROM chips...

Carts bigger than 16kb need both areas - but can use the memory from $4000-$BFFF (or $5000-$BFFF on a Laser 2001) as they want, because it is one continuous block... and the Creativision will select the blocks correctly.

I attach my memorymap again to maybe make things clearer

Greetings, TOM:0)
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