mirror of
https://github.com/kalymos/PsNee.git
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67 lines
4.7 KiB
Plaintext
67 lines
4.7 KiB
Plaintext
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VERSION 2! :D
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What has changed?
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- Thanks to TriMesh, the gate-pin is now also used to determine in which model of
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Playstation PsNee is installed. The modchip algorithm thus can be optimized for
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optimal performance on specific Playstation revisions. This works by monitoring
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whether a clock signal is present on this pin - when there is one, the modchip is
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installed in a PU-22, PU-23 or PSOne Playstation, else it is installed in an older
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model Playstation. In this version of PsNee, nothing is actually done with this information.
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- Thanks to -again- TriMesh, NTSC support for PAL SCPH-102 Playstations is added! This uses
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the same method the OneChip modchip used for achieving this:
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1. Monitor the XLAT signal from the CD mechanism controller chip. This requires
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another connection to the Playstation. When this signal is 0, the first CD copy
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protection is passed! After this, there is another one.
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2. After this, watch the Address18-pin (pin 31) on the BIOS-chip. When this signal
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is high, this means the second CD copy protection is about to run.
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3. Wait a short time.
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4. Pull the Data2-pin (pin 15) on the BIOS-chip to 0. This effectively blocks the
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execution of the region check of the inserted disc.
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5. The Playstation plays the inserted disc and doesn't care whether it's PAL or NTSC!
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6. Release the 0 of the Data2-pin.
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To correctly output a PAL video color signal for a PAL TV on a PAL PSOne with an NTSC disc
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inserted, Pin 3 of IC502 must be grounded with an external switch. The modchip also could do
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this, although we would need a device with more pins available.
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- The outputted data signal is now "sliced up" to improve (or less distort) the tracking
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signal from the CD mechanism: later Playstations use the CD tracking signal for transmitting
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the SCEx-string to the Playstation instead of using a seperate connection, so when the modchip
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forces a 0 on the data-pin, the tracking signal also is gone temporarily. By slicing the data-
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signal up in little pieces at least some of the tracking signal remains and the Playstation can
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read discs more easily.
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- The two big for-loops are combined into one with an OR-statement describing the two conditions
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modchip should be active: when flagFirstCycle = 0 or when flagFirstCycle = 1 and the lid is opened
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and closed again. This makes code maintenance easier.
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- The pin-out of the modchip is changed slightly to be able to use an interrupt for the PAL=>NTSC
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BIOS-patch for PAL SCPH-102. Please use the revised pin-out found below with this code.
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~TheFrietMan, The Netherlands
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--------------------------------------------------------------
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New in this version! V6
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--------------------------------------------------------------
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A lot!
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- The PAL SCPH-102 NTSC BIOS-patch works flawlessly! For speed reasons this is implemented in bare
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AVR C. It is functionally identical to the OneChip modchip, this modchip firmware was disassembled,
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documented (available on request, but written in Dutch...) and analyzed with a logic analyzer to
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make sure PsNee works just as well.
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- The code now is segmented in functions which make the program a lot more maintable and readable
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- Timing is perfected, all discs (both backups and originals of PAL and NTSC games) now work in the
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PAL SCPH-102 test machine
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- It was found out that the gate signal doesn't havbe to be hooked up to a PAL SCPH-102 Playstation
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to circumvent the copy protection. This is not tested on other Playstation models so the signal still
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is available
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- The /xlat signal is no longer required to time the PAL SCPH-102 NTSC BIOS-patch
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- Only AVR PORTB is used for compatibility reasons (almost all the AVR chips available have PORTB)
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--------------------------------------------------------
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AttyNeeRC3
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I just have a lot of Attiny13a and normal firmware for them was not.
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Modavr does not support stealth, and does not launch copies from NTSC disks on the slime.
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Then I came across the American firmware PsNee. It can patch bios slimki for NTSC disks.
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But it did not support Attiny13a (it exceeded the size and used the flash.h not supported in Attiny13a).
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Plus, the firmware itself was a compilation of different authors and contained a lot of garbage occupying a precious place.
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Also there were glitches with a fast disk change. I corrected and optimized the code well and added support for Attiny13a.
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That's basically it :)
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Before the firmware, pay attention to define and the function inject_SCEx (). In the comments all are indicated.
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