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- dbz.cpp: fixed typo in address map range

Browse Source 
- sg1000a.cpp: preliminary work on sderbys' decryption

- segacrpt_device.cpp: fixed typo in comments
This commit is contained in:
Ivan Vangelista 2020-12-18 20:40:29 +01:00
parent d52292004a
commit 2388a57ab9
3 changed files with 35 additions and 11 deletions
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2
src/mame/drivers/dbz.cpp
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@ -148,7 +148,7 @@ void dbz_state::dbz2bl_map(address_map &map)
map(0x4d4f00, 0x4d4f1f).w(m_k053936_2, FUNC(k053936_device::ctrl_w));
map(0x4e4000, 0x4e4001).unmapr();
map(0x4e0004, 0x4e4005).lr8(NAME([this]() { return uint8_t(m_dsw2->read()); }));
map(0x4e0004, 0x4e0005).lr8(NAME([this]() { return uint8_t(m_dsw2->read()); }));
map(0x4e3011, 0x4e3011).w("soundlatch", FUNC(generic_latch_8_device::write));
map(0x4f0000, 0x4f0001).unmapw();

42
src/mame/drivers/sg1000a.cpp
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@ -278,6 +278,8 @@ End
#include "speaker.h"
namespace {
class sg1000a_state : public driver_device
{
public:
@ -287,6 +289,7 @@ public:
m_decrypted_opcodes(*this, "decrypted_opcodes") { }
void sderbys(machine_config &config);
void sderby2s(machine_config &config);
void sg1000ax(machine_config &config);
void sg1000a(machine_config &config);
@ -502,7 +505,7 @@ void sg1000a_state::sg1000ax(machine_config &config)
maincpu.set_decrypted_tag(":decrypted_opcodes");
}
void sg1000a_state::sderbys(machine_config &config)
void sg1000a_state::sderby2s(machine_config &config)
{
sg1000a(config);
m_maincpu->set_clock(XTAL(10'738'635) / 3);
@ -511,6 +514,11 @@ void sg1000a_state::sderbys(machine_config &config)
// Actually uses a Sega 315-5066 chip, which is a TMS9918 and SN76489 in the same package but with RGB output
}
void sg1000a_state::sderbys(machine_config &config)
{
sderby2s(config);
m_maincpu->set_addrmap(AS_OPCODES, &sg1000a_state::decrypted_opcodes_map);
}
/*************************************
*
* ROM definitions
@ -558,16 +566,32 @@ ROM_END
void sg1000a_state::init_sderby()
{
// mini daughterboard in ic10 socket, with TI 27C128 rom and unknown ic(label scraped off)
u8 *rom = machine().root_device().memregion("maincpu")->base();
const u32 len = memregion("maincpu")->bytes();
// mini daughterboard in ic10 socket, with TI 27C128 rom and unknown ic (label scraped off)
u8 *rom = memregion("maincpu")->base();
for (int i = 0; i < len; i++)
rom[i] = bitswap<8>(rom[i],3,7,4,6,5,2,1,0);
// TODO: there's something fishy in the first 0x130 bytes, then it seems to be correct.
// i.e. compare the following addresses
// sderbys sderby2s
// 0x134 0x13c
// 0x237 0x280
// 0x2ad 0x336
// 0x402 0x4ac
// 0x11f1 0x132b
// 0x1300 0x1413
// 0x1680 0x1793
// TODO: decryption is unfinished
for (int i = 0; i < 0x4000; i++)
{
if (i < 0x100) // this is wrong
m_decrypted_opcodes[i] = bitswap<8>(rom[i], 3, 7, 4, 6, 5, 2, 1, 0);
else
m_decrypted_opcodes[i] = bitswap<8>(rom[i], 3, 7, 4, 5, 6, 2, 1, 0);
rom[i] = bitswap<8>(rom[i], 3, 7, 4, 5, 6, 2, 1, 0);
}
}
} // Anonymous namespace
/*************************************
@ -582,5 +606,5 @@ GAME( 1985, dokidoki, 0, sg1000a, dokidoki, sg1000a_state, empty_init, ROT0, "S
// inputs aren't hooked up, probably needs to be connected to the main board anyway
// TODO: move these guys over to sderby2.cpp
GAME( 1984, sderbys, 0, sderbys, sderbys, sg1000a_state, init_sderby, ROT0, "Sega", "Super Derby (satellite board)", MACHINE_NOT_WORKING )
GAME( 1985, sderby2s, 0, sderbys, sderbys, sg1000a_state, empty_init, ROT0, "Sega", "Super Derby II (satellite board)", MACHINE_NOT_WORKING )
GAME( 1984, sderbys, 0, sderbys, sderbys, sg1000a_state, init_sderby, ROT0, "Sega", "Super Derby (satellite board)", MACHINE_NOT_WORKING ) // decryption incomplete, currently displays IC23 and IC24 bad if resetted a few times
GAME( 1985, sderby2s, 0, sderby2s, sderbys, sg1000a_state, empty_init, ROT0, "Sega", "Super Derby II (satellite board)", MACHINE_NOT_WORKING )

2
src/mame/machine/segacrpt_device.cpp
View File

@ -11,7 +11,7 @@
epoxy block which probably contains a standard Z80 + PALs.
The encryption affects D3, D5, and D7, and depends on M1, A0, A4, A8 and A12.
D0, D1, D3, D4 and D6 are always unaffected.
D0, D1, D2, D4 and D6 are always unaffected.
The encryption consists of a permutation of the three bits, which can also be
inverted. Therefore there are 3! * 2^3 = 48 different possible encryptions.