Konami Sound Cartridge
Encyclopedia
The Konami Sound Cartridge is supplied with the MSX
video games Snatcher
and SD Snatcher
. Sometimes it is known as the SCC+. It includes a slightly improved Konami SCC
sound chip and 64kB of volatile RAM. It is likely that the RAM was included since most MSX computers in Japan
at the time of release had very little memory (mostly 64kB).
Like the normal SCC, the chip has 5 audio channels. The waveform is set by 32 bytes of 8 bit samples. Each channel has its own 32 bytes of waveform, unlike the SCC where channel 4 and 5 share the waveform.
The cartridge included with Snatcher is different than the one included with SD Snatcher, but only in memory layout. It was probably
done to make it incompatible. Some MSX emulators emulate this cartridge, MESS
and OpenMSX
for example.
Most video games on the Konami Games Collections for the MSX can use the cartridge that is included with Snatcher for better sound. Apart from those the Sound Cartridge is not used by any other programs.
The print on the chip is: KONAMI 052539 SCC-I2312P001 JAPAN followed by a fabrication location/date number, like 8951EAI. The first two digits are the year, followed by the week. The letters after that are some location/lot code.
types of cartridges become identical. The cartridge will work with both the SD Snatcher and Snatcher video games.
Surprisingly enough, a cartridge with 128kB RAM can behave exactly like a SCC ROM cartridge
of 128kB. This means you can load
those games into the RAM (e.g. Gradius 2
, F1 Spirit, Quarth
and so on) and it will behave like the original ROM
cartridge until the power is turned off, since it is volatile RAM. It is possible that this chip was originally developed for internal development and testing use at Konami
.
The RAM ICs are of type 4464. They are four bits wide and a 64K range. There might still some solder in the holes, you can use a solder sucker for that.
If you would like the cartridge to work with both video games then you can also connect the memory banks (so they are mirrored). Connect CAS (pin 16 of RAM IC) of one of the RAM ICs with one of the empty slots.
ROM cartridges.
As with SCC cartridges, the memory is divided into four memory banks of 8kB:
Bank 1 : 4000h - 5FFFh
Bank 2 : 6000h - 7FFFh
Bank 3 : 8000h - 9FFFh
Bank 4 : A000h - BFFFh
To change the mapping, write to one of these addresses:
Bank 1 : 5000h - 57FFh
Bank 2 : 7000h - 77FFh
Bank 3 : 9000h - 97FFh
Bank 4 : B000h - B7FFh
Bits 3 through 7 are ignored. Values 0 to 7 select 8kB pages of the lower 64kB (which is included with Snatcher) and values 8 to 15 the higher
64kB (which is included with SD Snatcher).
By default (after reset) bank 1 selected area 0, bank 2 area 1, bank 3 area 2 and bank 4 area 3. Again this is the same as SCC ROM cartridges. If the lower 64kB is empty (as it is with the Super Deform Snatcher cartridge) then the memory will be empty (reads FFh).
By default, the RAM cannot be changed. By setting a bit somewhere else the areas can no longer be changed (ROM mode) but can be written to
(RAM mode). This is done by writing to the mode register, which is always accessible through address BFFEh and BFFFh. The SCC can be put in also
be put in SCC+ mode through this register, where channel 4 and 5 do not share a waveform.
bit 7 : no function
bit 6 : no function
bit 5 : if set, sound chip is in SCC+ mode otherwise SCC compatibility
bit 4 : if set, banks 1 to 3 are in RAM mode otherwise area select
bit 3 : no function
bit 2 : if set and bit 5 reset, bank 3 is RAM mode irrespective of bit 4
bit 1 : if set, bank 2 is RAM mode irrespective of bit 4
bit 0 : if set, bank 1 is RAM mode irrespective of bit 4
Even in RAM mode the memory under BFFEh and BFFFh cannot be changed through those addresses as that will always end up in the mode register.
Konami uses 20h and 3Fh for the mode register as they always use SCC+ mode. 30h would also work for RAM mode.
layout is very similar to the SCC
and the meaning of the registers is the same although the address differ somewhat and the waveform of channel 5 can be read. The SCC is visible at 9800h through 9FDFh.
If bank 4 is in area select mode and bit 5 of the mode register is set, the SCC+ can be activated by writing a value with bit 7 set to anywhere
to B000h through B7FFh. Now the SCC+ becomes active at B800h through BFDFh.
MSX
MSX was the name of a standardized home computer architecture in the 1980s conceived by Kazuhiko Nishi, then Vice-president at Microsoft Japan and Director at ASCII Corporation...
video games Snatcher
Snatcher
is a cyberpunk-themed graphic adventure game produced by Konami, originally released in Japan for the NEC PC-8801 and MSX 2 computer platforms in 1988. It was followed by a CD-ROM-based remake released for the PC Engine video game console in 1992, which was subsequently ported and localized into...
and SD Snatcher
SD Snatcher
SD Snatcher is a role-playing video game by Konami for the MSX2 computer platform in exclusively in Japan. It is a spinoff of the original Snatcher, adapting the same storyline into a different genre...
. Sometimes it is known as the SCC+. It includes a slightly improved Konami SCC
Konami SCC
The Konami SCC is a custom sound chip that was developed by Konami with Yamaha. It is one of several sound/memory management chips Konami developed in-house that ended up in use in home computer and video game systems from the late 1980s into the 1990s until the fourth generation systems were...
sound chip and 64kB of volatile RAM. It is likely that the RAM was included since most MSX computers in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
at the time of release had very little memory (mostly 64kB).
Like the normal SCC, the chip has 5 audio channels. The waveform is set by 32 bytes of 8 bit samples. Each channel has its own 32 bytes of waveform, unlike the SCC where channel 4 and 5 share the waveform.
done to make it incompatible. Some MSX emulators emulate this cartridge, MESS
MESS
Multi Emulator Super System is an emulator for many game consoles and computer systems, based on the MAME core.The primary purpose of MESS is to preserve decades of computer and console history...
and OpenMSX
OpenMSX
openMSX is an open source MSX emulator which is free according to the Debian Free Software Guidelines, available under the GNU General Public License....
for example.
Most video games on the Konami Games Collections for the MSX can use the cartridge that is included with Snatcher for better sound. Apart from those the Sound Cartridge is not used by any other programs.
The print on the chip is: KONAMI 052539 SCC-I2312P001 JAPAN followed by a fabrication location/date number, like 8951EAI. The first two digits are the year, followed by the week. The letters after that are some location/lot code.
Expanding memory
It is possible to expand the memory to 128kB by adding 64kB of RAM to the cartridge. There are two open places on the PCB. When the RAM is added, bothtypes of cartridges become identical. The cartridge will work with both the SD Snatcher and Snatcher video games.
Surprisingly enough, a cartridge with 128kB RAM can behave exactly like a SCC ROM cartridge
ROM cartridge
A ROM cartridge, sometimes referred to as a cart, is a removable enclosure containing read-only memory devices designed to be connected to a computer or games console....
of 128kB. This means you can load
those games into the RAM (e.g. Gradius 2
Gradius
The Gradius games, first introduced in 1985, make up a series of scrolling shooter video games published by Konami for a variety of portable, console and arcade platforms. In many games in the series, the player controls a ship known as the Vic Viper...
, F1 Spirit, Quarth
Quarth
is a hybrid puzzle game/shoot 'em up developed by Konami which was released in 1989 as an arcade game, sold as Block Hole outside Japan. Besides the arcade version, there were also ports of the game to the MSX2 , Famicom, and Game Boy—home releases used the Quarth name worldwide is a hybrid puzzle...
and so on) and it will behave like the original ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
cartridge until the power is turned off, since it is volatile RAM. It is possible that this chip was originally developed for internal development and testing use at Konami
Konami
is a Japanese leading developer and publisher of numerous popular and strong-selling toys, trading cards, anime, tokusatsu, slot machines, arcade cabinets and video games...
.
The RAM ICs are of type 4464. They are four bits wide and a 64K range. There might still some solder in the holes, you can use a solder sucker for that.
If you would like the cartridge to work with both video games then you can also connect the memory banks (so they are mirrored). Connect CAS (pin 16 of RAM IC) of one of the RAM ICs with one of the empty slots.
Using the memory
Everything is done using memory-mapped I/O and it is much like the SCCKonami SCC
The Konami SCC is a custom sound chip that was developed by Konami with Yamaha. It is one of several sound/memory management chips Konami developed in-house that ended up in use in home computer and video game systems from the late 1980s into the 1990s until the fourth generation systems were...
ROM cartridges.
As with SCC cartridges, the memory is divided into four memory banks of 8kB:
Bank 1 : 4000h - 5FFFh
Bank 2 : 6000h - 7FFFh
Bank 3 : 8000h - 9FFFh
Bank 4 : A000h - BFFFh
To change the mapping, write to one of these addresses:
Bank 1 : 5000h - 57FFh
Bank 2 : 7000h - 77FFh
Bank 3 : 9000h - 97FFh
Bank 4 : B000h - B7FFh
Bits 3 through 7 are ignored. Values 0 to 7 select 8kB pages of the lower 64kB (which is included with Snatcher) and values 8 to 15 the higher
64kB (which is included with SD Snatcher).
By default (after reset) bank 1 selected area 0, bank 2 area 1, bank 3 area 2 and bank 4 area 3. Again this is the same as SCC ROM cartridges. If the lower 64kB is empty (as it is with the Super Deform Snatcher cartridge) then the memory will be empty (reads FFh).
By default, the RAM cannot be changed. By setting a bit somewhere else the areas can no longer be changed (ROM mode) but can be written to
(RAM mode). This is done by writing to the mode register, which is always accessible through address BFFEh and BFFFh. The SCC can be put in also
be put in SCC+ mode through this register, where channel 4 and 5 do not share a waveform.
bit 7 : no function
bit 6 : no function
bit 5 : if set, sound chip is in SCC+ mode otherwise SCC compatibility
bit 4 : if set, banks 1 to 3 are in RAM mode otherwise area select
bit 3 : no function
bit 2 : if set and bit 5 reset, bank 3 is RAM mode irrespective of bit 4
bit 1 : if set, bank 2 is RAM mode irrespective of bit 4
bit 0 : if set, bank 1 is RAM mode irrespective of bit 4
Even in RAM mode the memory under BFFEh and BFFFh cannot be changed through those addresses as that will always end up in the mode register.
Konami uses 20h and 3Fh for the mode register as they always use SCC+ mode. 30h would also work for RAM mode.
Using the sound chip
If bank 3 is in area select mode and bit 5 of mode register is reset, the SCC can be activated by writing 3Fh to one address 9000h through 97FFh. Thelayout is very similar to the SCC
Konami SCC
The Konami SCC is a custom sound chip that was developed by Konami with Yamaha. It is one of several sound/memory management chips Konami developed in-house that ended up in use in home computer and video game systems from the late 1980s into the 1990s until the fourth generation systems were...
and the meaning of the registers is the same although the address differ somewhat and the waveform of channel 5 can be read. The SCC is visible at 9800h through 9FDFh.
| Address | read/write | Function |
|---|---|---|
| 9800h - 981Fh | rw | waveform channel 1 |
| 9820h - 983Fh | rw | waveform channel 2 |
| 9840h - 985Fh | rw | waveform channel 3 |
| 9860h - 987Fh | rw | read: waveform channel 4 write: waveform channel 4 and 5 |
| 9880h - 9881h | w | frequency channel 1 |
| 9882h - 9883h | w | frequency channel 2 |
| 9884h - 9885h | w | frequency channel 3 |
| 9886h - 9887h | w | frequency channel 4 |
| 9888h - 9889h | w | frequency channel 5 |
| 988Ah | w | volume channel 1 |
| 988Bh | w | volume channel 2 |
| 988Ch | w | volume channel 3 |
| 988Dh | w | volume channel 4 |
| 988Eh | w | volume channel 5 |
| 988Fh | w | on/off switch channel 1 to 5 |
| 9890h - 989Fh | w | same as 9880h to 988Fh |
| 98A0h - 98BFh | w | waveform channel 5 |
| 98C0h - 98DFh | rw | deformation register |
| 98E0h - 98FFh | no function |
If bank 4 is in area select mode and bit 5 of the mode register is set, the SCC+ can be activated by writing a value with bit 7 set to anywhere
to B000h through B7FFh. Now the SCC+ becomes active at B800h through BFDFh.
| Address | read/write | Function |
|---|---|---|
| B800h - B81Fh | rw | waveform channel 1 |
| B820h - B83Fh | rw | waveform channel 2 |
| B840h - B85Fh | rw | waveform channel 3 |
| B860h - B87Fh | rw | waveform channel 4 |
| B880h - B89Fh | rw | waveform channel 5 |
| B8A0h - B8A1h | w | frequency channel 1 |
| B8A2h - B8A3h | w | frequency channel 2 |
| B8A4h - B8A5h | w | frequency channel 3 |
| B8A6h - B8A7h | w | frequency channel 4 |
| B8A8h - B8A9h | w | frequency channel 5 |
| B8AAh | w | volume channel 1 |
| B8ABh | w | volume channel 2 |
| B8ACh | w | volume channel 3 |
| B8ADh | w | volume channel 4 |
| B8AEh | w | volume channel 5 |
| B8AFh | w | on/off switch channel 1 to 5 |
| B8B0h - B8BFh | w | same as B8A0h to B8AFh |
| B8C0h - B8DFh | rw | deformation register |
| B8E0h - B8FFh | no function |