Bad modding of my PU-18 5502

General information to do with the PlayStation 1 Hardware. Including modchips, pinouts, rare or obscure development equipment, etc.
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Joined: December 12th, 2018, 5:07 am

Bad modding of my PU-18 5502

Post by electronic-jack » December 12th, 2018, 6:37 am

Hi all
This is my first post here and I'm also new to the whole PS1 hacking thing
I had an ATtiny13 laying around so I looked for and found a mod running on this chip

This mod is modavr ( which is one of these mods that just spam SCEA/SCEE/SCEI in an infinite loop
It even contains the .hex file to flash the ATtiny13 with
So I flashed this program to my chip and *tried* to solder the chip

My first problem was identifying pads as I never was able to find a simple picture that states the name of pads
I had to guess and I think this is correct: 5 is GATE and 6 is DATA (right?)

Currently I have the ATtiny13 soldered with these links (chip pin vs number is the picture above) (*):
PB0 = (5)
PB1 = (6)
VCC = (1)
GND = (8)

Problem #1
While trying to solder to the (5) pad, I actually make it disappear (bad soldering iron I guess)
I don't know how to describe this but the pad disn't shine anymore at all, so I finally tried to solder directly to the pin and I think it worked
Sadly it's so tiny I can't make a clear picture of the mess what I've done
So, is this pad necessary there is no problem leaving things as they are?

Problem #2
After plugging everything back the behaviour of the PS1 changed
Previsouly it was able to load legit games and now it can't even boot legit games (V-Rally is seen as an audio CD and Disney's Hercules gives the following screen)

So, what could I have done and how can I investigate this?
What I don't get is why now it can't boot anything
I can't work on that right now but I guess I'll have to disconnect the chip to see if the damage is permanent

(*) ... modavr.asm

Code: Select all

; Pin connections:
; 1 - n/c
; 2 - n/c
; 3 - n/c
; 4 - GND
; 5 - GATE
; 6 - DATA
; 7 - n/c
; 8 - VCC

Code: Select all

; mod-chip pins
.equ GATE	= PB0
.equ DATA	= PB1

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