Search found 68 matches

by zerowalker
Sun May 06, 2018 2:05 am
Forum: GBDev
Topic: DMA Transfer - 160 microseconds?
Replies: 16
Views: 13201

Re: DMA Transfer - 160 microseconds?

How come some instructions need decoding that takes 4 cycles?
For CB i get it, i assume it takes 4 cycles to read the next 8 bits, and then 4 cycles to execute it (if it's on a register only).
by zerowalker
Fri May 04, 2018 9:57 am
Forum: GBDev
Topic: When are Interruptions signaled and launched?
Replies: 0
Views: 8644

When are Interruptions signaled and launched?

Hi, (I know how IE/IF sets the trigger, so that's not the question) So i find this a little bit confusing. From my understanding, the Interruptions is launched before fetching the next instruction. But is that also when the check for IF/IE happens, or does that happen on the cycle where either IF or...
by zerowalker
Wed Nov 01, 2017 4:20 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

Hmm, doesn't seem to yield any difference on the LCD at 50k, 20k, 10k etc:(
by zerowalker
Wed Nov 01, 2017 4:02 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

Tried connecting from the Resistor (Pin side), but nothing comes up in the Logic Analyzer, with or without ground connected to it.
Can also note that the LCD itself doesn't work as before either.
by zerowalker
Wed Nov 01, 2017 3:51 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

Yeah it's 0 on both voltages from pin to ground. And there's no DC voltage if i touch each end of the resistor either, but there's a AC voltage. Will recheck so i am not lying lol EDIT: Okay was lying haha, there is about 4.57 DC voltage across the resistor, no clue why i didn't get that before, mus...
by zerowalker
Wed Nov 01, 2017 3:33 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

Was i supposed to check VAC between the resistors ends, cause if not and it was supposed to be from HSYNC side to Ground, then sadly it's 0 on DC and AC:(
by zerowalker
Wed Nov 01, 2017 2:02 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

Okay connected HSYNC to the VCC on the Link connector (Pin 1, opposite of Ground i hope). Then i check with the multimeter on each side of the resistor, i get no DC voltage, and AC (set on 200) get about 09.1, i guess that's a good thing? EDIT: or wait, maybe i was supposed to check between HSYNC an...
by zerowalker
Wed Nov 01, 2017 1:23 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

Hmm looking at the schematics, how would i know where it's actually on the board.

Are the Link port pins here: https://abload.de/img/gameboy_innen_img_0179su73.jpg ?
by zerowalker
Wed Nov 01, 2017 12:42 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

Ah okay. I have checked between the HSYNC and Ground, and there is 0 volt when the GB is on, so i will have to try connect a resistor to 5v regulated. Where does that occur, is it the daughter board? I usually power my GB via an USB 5v i soldered to the battery (if that has any impact). My multi-met...
by zerowalker
Wed Nov 01, 2017 5:24 am
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

I got a ton of different resistors ready, how would i measure to see what the Mosfet would be doing and where do i connect it?
(I got no oscilloscope, but got multimeter and analyzer).
by zerowalker
Tue Oct 31, 2017 1:37 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

Not familiar with inverters sadly, it kinda looks like transistor and opamp or something when i look at your code there O.o. Hmm, but where do i connect the resistor in order to nodge that mosfet? probably super obvious but kinda lost when i see the mosfet being on the die, the hsync pin being outsi...
by zerowalker
Tue Oct 31, 2017 1:12 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

So basically i want to make the mosfet have a voltage to it's gate very near the "open" voltage, so just a little boost from the device itself would turn it on? hmm, or wait that doesn't feel right. I know a bit about mosfets, but i mostly just understand them as P-Channel = give volt and it closes,...
by zerowalker
Tue Oct 31, 2017 12:52 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

A bit confused, where would i add this resistor if the Mosfet that's broken is on the die:s?

To me a resistor would prevent current, not act as a little booster. But then again i am very new to electronics.

Thanks;D
by zerowalker
Tue Oct 31, 2017 12:01 pm
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

Not seeing anything broken more or less only eliminates "you didn't break the pin off outside the epoxy package". What did I say that sounded like "just connect the HSYNC to ground" ? here: or to gnd if the pin is instead always high) EDIT: okay assume it was about HSYNC pin, didn't think what you ...
by zerowalker
Tue Oct 31, 2017 11:57 am
Forum: GBDev
Topic: Broken HSYNC (probably short circuited it or something)
Replies: 26
Views: 5838

Re: Broken HSYNC (probably short circuited it or something)

I can't seem to detect anything that's broken visually at least (like burnt off), but then again it might be hard to detect.

Should i just connect the HSYNC to ground? wouldn't that just make nothing reach the LCD?