diff options
Diffstat (limited to 'src/mame/drivers/odyssey2.cpp')
-rw-r--r-- | src/mame/drivers/odyssey2.cpp | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/src/mame/drivers/odyssey2.cpp b/src/mame/drivers/odyssey2.cpp index 24980e784dd..a8ee2a172b4 100644 --- a/src/mame/drivers/odyssey2.cpp +++ b/src/mame/drivers/odyssey2.cpp @@ -54,14 +54,20 @@ XTAL notes (differs per model): TODO: - backgamm doesn't draw all the chars/sprites, it does multiple screen updates and writes to the ptr/color registers, but does not increment the Y regs -- 824x screen resolution is not strictly defined, height(243) is correct, but +- screen resolution is not strictly defined, height(243) is correct, but horizontal overscan differs depending on monitor/tv? see syracuse for overscan - 824x on the real console, overlapping characters on eachother will cause glitches (it is used to an advantage in some as-of-yet undumped homebrews) - 8244(NTSC) is not supposed to show characters near the upper border, but hiding them will cause bugs in some Euro games -- 8245(PAL) video timing is not 100% accurate, though vtotal and htotal should - be correct +- according to tests, 8244 does not have a sound interrupt, but the Philips + service test cartridge for 8245 tests for it and fails if it did not get an irq +- likewise, 8244 does not have a horizontal interrupt, but does 8245 have it? +- tests done on 8244 suggests that Y(0xa4) is latched when reading X, but + that is inconsistent with the Philips service test cartridge: It reads X, Y, X, + then waits for 1 scanline, and reads Y again. It expects Y to change. Latching Y + will also cause video glitches to look different on some games when compared + to the real console, for example powerlrd. - ppp(the tetris game) does not work properly on PAL, is this homebrew NTSC-only, or is PAL detection going wrong? It does look like PAL/NTSC detection is working, see internal RAM $3D d7. So maybe it is due to inaccurate PAL video timing. |