Search found 1047 matches

by Jeroen
Sun May 16, 2021 5:09 pm
Forum: Newbie Help Center
Topic: Famicom part of sprites are below where they should be
Replies: 5
Views: 4001

Re: Famicom part of sprites are below where they should be

To me that looks like either the OAM ram inside the ppu is broken. Or your famicom RAM chip is broken, and the broken data is copied to the OAM.

Hopefully it is the latter, because RAM chips can be bought easily, PPU chips not so much.
by Jeroen
Fri Nov 20, 2020 2:26 pm
Forum: NES Hardware and Flash Equipment
Topic: How to design the PCB of PIC18f2520 microcontroller
Replies: 9
Views: 5082

Re: How to design the PCB of PIC18f2520 microcontroller

That's like people who say you don't need bypass caps because "it worked for me". I say that on purpose to show clearly that I don't have anything to back up my statements, even encouraging to look up the datasheet. It's just my experience, making sure you know that and not hiding anythin...
by Jeroen
Fri Nov 20, 2020 2:07 pm
Forum: NES Hardware and Flash Equipment
Topic: How to design the PCB of PIC18f2520 microcontroller
Replies: 9
Views: 5082

Re: How to design the PCB of PIC18f2520 microcontroller

That's like people who say you don't need bypass caps because "it worked for me". I say that on purpose to show clearly that I don't have anything to back up my statements, even encouraging to look up the datasheet. It's just my experience, making sure you know that and not hiding anythin...
by Jeroen
Fri Nov 20, 2020 11:42 am
Forum: NES Hardware and Flash Equipment
Topic: How to design the PCB of PIC18f2520 microcontroller
Replies: 9
Views: 5082

Re: How to design the PCB of PIC18f2520 microcontroller

Sorry but I have to disagree with that completely aquasnake. First of all, I advise against the diodes because then the voltage getting to the PIC micro will be less by a diode drop. You could check the datasheet to be sure but 99.9992% chance the regulator doesn't care if its output gets powered w...
by Jeroen
Thu Nov 05, 2020 7:39 am
Forum: NES Hardware and Flash Equipment
Topic: Hori Game Repeater
Replies: 8
Views: 7115

Re: Hori Game Repeater

Interesting analysis! It does seem quite cheaply made. (and hard to use) As for the PCB being paper, I do think it helps to have some perspective on things. At the end of the day this would've been considered a toy, so there were probably (paper ;) ) thin margins. I suspect the reason they didn't co...
by Jeroen
Sun Oct 04, 2020 6:17 am
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 618
Views: 342353

Re: Reverse Engineering the CIC

I guess that settles it, the 3198A (probably) cannot be dumped this way. I suppose a decap will be neccessary.
by Jeroen
Thu Oct 01, 2020 3:42 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 618
Views: 342353

Re: Reverse Engineering the CIC

One could try pulling R22 low, perhaps that controls the page.

edit: alternatively, one could try setting R20 or R21 high. with two pins you can adress 4 pages.
by Jeroen
Thu Oct 01, 2020 3:14 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 618
Views: 342353

Re: Reverse Engineering the CIC

Here's a quick test for 1016 bytes: //sm590 dumper script //Written by Jero32 24/09/2020 //to run, hook the arduino pins up to sm590 chip according to pinout below. Upload sketch to arduino. Clear the terminal window //and press the reset button //do one clock cycle. Note: relies on opcodes taking t...
by Jeroen
Thu Oct 01, 2020 2:51 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 618
Views: 342353

Re: Reverse Engineering the CIC

Hey it worked! Neat. I guess now someone has to analyze the code to see if it's all there. edit: I hope this is a more "proper" fix, I added a serial.flush command after sending some data, maybe the buffer was overloading or something. If you wouldn't mind trying it out. //sm590 dumper scr...
by Jeroen
Thu Oct 01, 2020 2:37 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 618
Views: 342353

Re: Reverse Engineering the CIC

it stops after printing i1F5 with the newer code, the old code https://pastebin.com/raw/aQFhF3DC I get the following *log here* The print loop is independent of the actual data read, so maybe it's not sending out the buffer, gimme a sec and I'll look up documentation on that. Try this: //sm590 dump...
by Jeroen
Thu Oct 01, 2020 2:01 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 618
Views: 342353

Re: Reverse Engineering the CIC

Sadly I think your famicombox cic('s) is (/are) just dead :(
by Jeroen
Thu Oct 01, 2020 1:38 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 618
Views: 342353

Re: Reverse Engineering the CIC

Using the last arduino code posted I got the following on the 3199A chip. i0 :75 i1 :30 i2 :4A i3 :74 i4 :42 i5 :C0 i6 :7D i7 :A6 i8 :7E i9 :7D iA :7D iB :D3 iC :7D iD :CA iE :7E iF :5B i10 :75 i11 :22 i12 :63 i13 :9D i14 :0 i15 :28 i16 :52 i17 :EB i18 :EC i19 :74 i1A :22 i1B :60 i1C :B0 i1D :D7 i1...
by Jeroen
Thu Oct 01, 2020 10:07 am
Forum: Reproduction
Topic: Using non CMOS eproms on NES Carts
Replies: 11
Views: 7634

Re: Using non CMOS eproms on NES Carts

Reading the datasheet, it seems the /G enable signal going low is what latches the data out on that particular chip. Make sure your address decoding is connected to that particular pin. https://futurlec.com/Memory/27128_Datasheet.shtml edit I checked some pictures of nrom pcbs online: https://www.ni...
by Jeroen
Sun Sep 27, 2020 5:06 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 618
Views: 342353

Re: Reverse Engineering the CIC

If you'd like a 6113B1, I believe they're the standard in NES Play Action Football, which is a very cheap game; I was getting mine for $2 at the local game shop. Sadly I live in Pal territory, so getting even cheap ntsc games is a hassle. edit, btw fiskbit, did you try my updated code where I bring...
by Jeroen
Sun Sep 27, 2020 4:32 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 618
Views: 342353

Re: Reverse Engineering the CIC

Do we know why the 6113B won’t dump either? Mine is a working chip. I can try another game, I did get a proper desoldering setup to prevent messing up anything on the main board repairs. I do not know at this point, but without using an oscilloscope and actually seeing what's going on, it becomes a...