diff --git a/changelog b/changelog new file mode 100644 index 0000000..da21fd0 --- /dev/null +++ b/changelog @@ -0,0 +1,57 @@ + +------------------------------------------------- +VERSION 2! :D +------------------------------------------------- +What has changed? + - Thanks to TriMesh, the gate-pin is now also used to determine in which model of + Playstation PsNee is installed. The modchip algorithm thus can be optimized for + optimal performance on specific Playstation revisions. This works by monitoring + whether a clock signal is present on this pin - when there is one, the modchip is + installed in a PU-22, PU-23 or PSOne Playstation, else it is installed in an older + model Playstation. In this version of PsNee, nothing is actually done with this information. + - Thanks to -again- TriMesh, NTSC support for PAL SCPH-102 Playstations is added! This uses + the same method the OneChip modchip used for achieving this: + 1. Monitor the XLAT signal from the CD mechanism controller chip. This requires + another connection to the Playstation. When this signal is 0, the first CD copy + protection is passed! After this, there is another one. + 2. After this, watch the Address18-pin (pin 31) on the BIOS-chip. When this signal + is high, this means the second CD copy protection is about to run. + 3. Wait a short time. + 4. Pull the Data2-pin (pin 15) on the BIOS-chip to 0. This effectively blocks the + execution of the region check of the inserted disc. + 5. The Playstation plays the inserted disc and doesn't care whether it's PAL or NTSC! + 6. Release the 0 of the Data2-pin. + To correctly output a PAL video color signal for a PAL TV on a PAL PSOne with an NTSC disc + inserted, Pin 3 of IC502 must be grounded with an external switch. The modchip also could do + this, although we would need a device with more pins available. + - The outputted data signal is now "sliced up" to improve (or less distort) the tracking + signal from the CD mechanism: later Playstations use the CD tracking signal for transmitting + the SCEx-string to the Playstation instead of using a seperate connection, so when the modchip + forces a 0 on the data-pin, the tracking signal also is gone temporarily. By slicing the data- + signal up in little pieces at least some of the tracking signal remains and the Playstation can + read discs more easily. + - The two big for-loops are combined into one with an OR-statement describing the two conditions + modchip should be active: when flagFirstCycle = 0 or when flagFirstCycle = 1 and the lid is opened + and closed again. This makes code maintenance easier. + - The pin-out of the modchip is changed slightly to be able to use an interrupt for the PAL=>NTSC + BIOS-patch for PAL SCPH-102. Please use the revised pin-out found below with this code. +~TheFrietMan, The Netherlands +-------------------------------------------------------------- + New in this version! V6 +-------------------------------------------------------------- +A lot! + - The PAL SCPH-102 NTSC BIOS-patch works flawlessly! For speed reasons this is implemented in bare + AVR C. It is functionally identical to the OneChip modchip, this modchip firmware was disassembled, + documented (available on request, but written in Dutch...) and analyzed with a logic analyzer to + make sure PsNee works just as well. + - The code now is segmented in functions which make the program a lot more maintable and readable + - Timing is perfected, all discs (both backups and originals of PAL and NTSC games) now work in the + PAL SCPH-102 test machine + - It was found out that the gate signal doesn't havbe to be hooked up to a PAL SCPH-102 Playstation + to circumvent the copy protection. This is not tested on other Playstation models so the signal still + is available + - The /xlat signal is no longer required to time the PAL SCPH-102 NTSC BIOS-patch + - Only AVR PORTB is used for compatibility reasons (almost all the AVR chips available have PORTB) + + +