[SOLVED] UNROM to UxROM 512 - gray screen

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mr-volk
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Joined: Mon Oct 21, 2013 11:32 pm

[SOLVED] UNROM to UxROM 512 - gray screen

Post by mr-volk » Wed Jul 16, 2014 10:43 pm

Trying to do uxrom 512 with 161 and 32 chips. But still - gray screen.
Is where error with schematic?

Image
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Last edited by mr-volk on Sat Aug 09, 2014 12:12 pm, edited 1 time in total.

mr-volk
Posts: 18
Joined: Mon Oct 21, 2013 11:32 pm

Re: UNROM to UxROM 512 - gray screen

Post by mr-volk » Thu Jul 17, 2014 12:32 am

Seems solution
ground 7 and 10 pins. Thx for nikita600.
Try later.

Ice Man
Posts: 526
Joined: Fri Jul 04, 2014 2:34 pm

Re: UNROM to UxROM 512 - gray screen

Post by Ice Man » Thu Jul 24, 2014 2:44 am

Hi, you found a solution now? I tried the same with ground pin 7 and 10, still grey screen.
Hope we find a fix soon!

Ice Man
Posts: 526
Joined: Fri Jul 04, 2014 2:34 pm

Re: UNROM to UxROM 512 - gray screen

Post by Ice Man » Sat Jul 26, 2014 7:36 am

Sorry for the double post but I read that using a 74HC377 and 2x74HC32 works as well? Is this true? Can anyone confirm that it is working and if yes, how is it wired? I'd love help for this project.

tepples
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Re: UNROM to UxROM 512 - gray screen

Post by tepples » Sat Jul 26, 2014 11:13 am

The inputs of the 74HC377 would be wired the same way they are on the Color Dreams board. Each output would be wired to one input of each of the 74HC32's OR gates, with CPU A14 to the other input.

Ice Man
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Re: UNROM to UxROM 512 - gray screen

Post by Ice Man » Tue Jul 29, 2014 2:49 am

Would you mind creating a diagram for that?
Does A14 go into the 1st pin of the 74377?
Help appreciated, since I'm pretty new to those custom mappers.

Ice Man
Posts: 526
Joined: Fri Jul 04, 2014 2:34 pm

Re: UNROM to UxROM 512 - gray screen

Post by Ice Man » Sat Aug 02, 2014 6:29 am

EDIT: I converted the game to MMC3. All works now.

mr-volk
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Re: UNROM to UxROM 512 - gray screen

Post by mr-volk » Sat Aug 09, 2014 12:09 pm

ground 7 and 10 pins
all other is right

Ice Man
Posts: 526
Joined: Fri Jul 04, 2014 2:34 pm

Re: [SOLVED] UNROM to UxROM 512 - gray screen

Post by Ice Man » Sat Aug 09, 2014 12:31 pm

I tried that. Only grey screen. Maybe I soldered something wrong.
Either way, I made TNROM board with SMB2 and it works now.
Thank you.

sdm
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Re: [SOLVED] UNROM to UxROM 512 - gray screen

Post by sdm » Wed Dec 27, 2017 9:39 am

Is this scheme correct? Because it is not clear whether the problem was finally solved.
I need to do UxROM 512KB, unfortunately I do not have 74xx377 but I have a lot of 74xx161 and xx32.

tepples
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Re: [SOLVED] UNROM to UxROM 512 - gray screen

Post by tepples » Wed Dec 27, 2017 10:56 am

Two 74161 and two 7432 make one oversize UxROM. You need to route D3 through one '161 and '32 to PRG ROM A17, as for the UNROM to UOROM mod, and do similarly with D4 to PRG ROM A18 through the other 161/32 pair.

3.14159td
Posts: 11
Joined: Fri Jul 24, 2015 2:44 pm

Re: [SOLVED] UNROM to UxROM 512 - gray screen

Post by 3.14159td » Wed Jul 03, 2019 2:12 pm

Spent a few hour over the weekend throwing this together. Tested and working with several games.
I hope the attached images help clear things up for anybody going through this thread in the future.
Attachments
IMG_E1672.JPG

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