27C-, 28F-, 29F-, 29EE-, 49F-, etc.
16, 32, 64, 128, 256, 512, 010, 020, 040, and maybe more.
Showing posts with label developement. Show all posts
Showing posts with label developement. Show all posts
Saturday, December 12, 2015
Odyssey 2 variety cart
I am also currently working on a flash cart for the Odyssey 2 that supports a wide array of roms, proms, eproms, etc.
27C-, 28F-, 29F-, 29EE-, 49F-, etc.
16, 32, 64, 128, 256, 512, 010, 020, 040, and maybe more.
27C-, 28F-, 29F-, 29EE-, 49F-, etc.
16, 32, 64, 128, 256, 512, 010, 020, 040, and maybe more.
SwinSID SE - reworked by Me
Been toying with the SwinSID which is a decent DIY version of the SID chip. My version takes up no more space than the original and would be a drop-in-replacement with no extra wiring. Programming the atmega would be a little difficult though since there is no room for an ICSP.
SMS variety Cart
Currently working on a flash cart for the SMS that supports a wide array of roms, proms, eproms, etc.
27C-, 28F-, 29F-, 29EE-, 49F-, etc.
16, 32, 64, 128, 256, 512, 010, 020, 040, and maybe more.
Problem is ... I don't own a Master System to test these out. I will not be printing any until I get one.
27C-, 28F-, 29F-, 29EE-, 49F-, etc.
16, 32, 64, 128, 256, 512, 010, 020, 040, and maybe more.
Problem is ... I don't own a Master System to test these out. I will not be printing any until I get one.
Tuesday, December 8, 2015
Composite Video from the Nintendo Gameboy
My latest project is to get some sort of video output from the nintendo gameboy. The signals are all present, but are not in a form that can be connected to any television or monitor. My first thought is to convert the signals into a single analog signal called composite video.
Composite video is named as such because it contains color data (chroma), brightness (luma) and synchronization on wire.
1. Chroma is not important in this case becuase the gameboy is monochrome. All of the color differences will be made with Luma.
2. Luma: As above, the Luma will be used to create our four different colors. The TV looks for an analog signal here. The gameboy has two data pins which are used for this purpose, so connected through a DAC of some sort, we can create four different levels rather than just 0v and 5v.
3. Sync
Csync or composite sync is an XOR of horizontal and vertical sync. These two signals tell the television to move down one line or to move back to the top of the screen. I am not quite sure how progressive or interlaced are determined by these just yet.
Next, these have to be connected together over one wire. As mentioned, the luma is an analog value but what I forgot to mention was that it is a positive signal whereas sync is negative. From what I have read, composite must be AC coupled because the TV input is DC coupled. That being said, our sync can actually be positive as well, as long as the luma is offset by DC value. Once the signal goes into the TV, the DC coupling circuit will block the average DC offset which is our black level. Black level will become 0 volts inside the Tv so sync will become 0v to -0.4v and Luma will be between 0v and +0.7v.
I am not at liberty to share my schematic at this point but it doesn't' work that well anyhow. :P
As a first attempt however, the result is quite promising.
You will notice that the image scrolls in several directions and that it is repeated three times over from left to right. I believe this is a problem with synchronization and possibly the LCD itself.
Composite video is named as such because it contains color data (chroma), brightness (luma) and synchronization on wire.
1. Chroma is not important in this case becuase the gameboy is monochrome. All of the color differences will be made with Luma.
2. Luma: As above, the Luma will be used to create our four different colors. The TV looks for an analog signal here. The gameboy has two data pins which are used for this purpose, so connected through a DAC of some sort, we can create four different levels rather than just 0v and 5v.
3. Sync
Csync or composite sync is an XOR of horizontal and vertical sync. These two signals tell the television to move down one line or to move back to the top of the screen. I am not quite sure how progressive or interlaced are determined by these just yet.
Next, these have to be connected together over one wire. As mentioned, the luma is an analog value but what I forgot to mention was that it is a positive signal whereas sync is negative. From what I have read, composite must be AC coupled because the TV input is DC coupled. That being said, our sync can actually be positive as well, as long as the luma is offset by DC value. Once the signal goes into the TV, the DC coupling circuit will block the average DC offset which is our black level. Black level will become 0 volts inside the Tv so sync will become 0v to -0.4v and Luma will be between 0v and +0.7v.
I am not at liberty to share my schematic at this point but it doesn't' work that well anyhow. :P
As a first attempt however, the result is quite promising.
You will notice that the image scrolls in several directions and that it is repeated three times over from left to right. I believe this is a problem with synchronization and possibly the LCD itself.
Updates to follow shortly.
Tuesday, February 11, 2014
NES TSOP ROM Adapter Development Board
The title is quite a mouth full, but I have been working on an adapter board for use in the NES. While EPROMs are still available for burning ROMs, (for development purposes of course) they are running out.
27C, 29F, 49F series chips, etc. They are no longer produced and as stocks dwindle, prices increase. Some companies do still make ROM chips though! The newly produced chip are rarely made in a DIL package though, so an adapter is needed, else the user very carefully hand solders each pin. Even with each pin hand soldered, how are you supposed to program the ROM to it? With an adapter, thats how.
So say you have an adapter for one such new ROM chip. Is the final pinout the same as a CHR mask ROM, PRG mask ROM or the old 27Cxxx/29Fxxx/49Fxxx pinout? How about all three? The thing that my adapter board has, which others may not, is solder-pad jumpers to change the pinout of the two rows of pins. Each pad is named so the user can see which pads to use when they want the pinout of a CHR ROM, PRG ROM or normal flash ROM.
The only draw back is that the Chip that I used, the GLS29EE010, is only a 1 MegaBit EEPROM. That is only 128 KiloBytes. Many NES ROMs are small enough to use these, but many complex RPG's are much larger. Now for a beginner NES programmer, 128KB is plenty of room.
Anyhow, the biggest reason that I wanted to make this adapter is so I can configure the board to be a 29F010, program it with my Willem Programmer and then reconfigure the pads for either a CHR ROM or a PRG ROM. This makes it so I do not have to modify the traces on an NES cart or connect wires all over the board.
In the pictures, you can see how far I have come. I still need to place the solder pads in convenient locations and the last thing I will do is make the board smaller. As you can see, the board protrudes past the through-hole pins. This small amount of extra board may not cause any problems, but it is best to be safe.
TOP:
BOTTOM:
SCHEMATIC:
UPDATE:
The above pictures are of my finished board. The top side contains the filter capacitor, a pull up resistor for the Write enable pin and the 128 KByte ROM itself.
The bottom side has all of the jumpers which are labelled accordingly. If you want the pinout of a CHR ROM, solder the jumpers which are labelled CHR, but if you want to program the chip with your EPROM burner with factory settings, the solder the 010 jumpers and set your programmer in software as a 29F010. Its as easy as that!
I have also reduced the size to 41.91mm x 19.05mm. The filter capacitor is optional since the standard cart will have one immediately next to the power pin of the original mask ROM. The pull up resistor is required unfortunately. Many IC's now-a-days have internal pull-up or down resistors so that pins can be left open or hanging, but the datasheet does not say anything about pull up resistors and this is not a pin we can leave to self-oscillate!
27C, 29F, 49F series chips, etc. They are no longer produced and as stocks dwindle, prices increase. Some companies do still make ROM chips though! The newly produced chip are rarely made in a DIL package though, so an adapter is needed, else the user very carefully hand solders each pin. Even with each pin hand soldered, how are you supposed to program the ROM to it? With an adapter, thats how.
So say you have an adapter for one such new ROM chip. Is the final pinout the same as a CHR mask ROM, PRG mask ROM or the old 27Cxxx/29Fxxx/49Fxxx pinout? How about all three? The thing that my adapter board has, which others may not, is solder-pad jumpers to change the pinout of the two rows of pins. Each pad is named so the user can see which pads to use when they want the pinout of a CHR ROM, PRG ROM or normal flash ROM.
The only draw back is that the Chip that I used, the GLS29EE010, is only a 1 MegaBit EEPROM. That is only 128 KiloBytes. Many NES ROMs are small enough to use these, but many complex RPG's are much larger. Now for a beginner NES programmer, 128KB is plenty of room.
Anyhow, the biggest reason that I wanted to make this adapter is so I can configure the board to be a 29F010, program it with my Willem Programmer and then reconfigure the pads for either a CHR ROM or a PRG ROM. This makes it so I do not have to modify the traces on an NES cart or connect wires all over the board.
In the pictures, you can see how far I have come. I still need to place the solder pads in convenient locations and the last thing I will do is make the board smaller. As you can see, the board protrudes past the through-hole pins. This small amount of extra board may not cause any problems, but it is best to be safe.
TOP:
BOTTOM:
SCHEMATIC:
UPDATE:
The above pictures are of my finished board. The top side contains the filter capacitor, a pull up resistor for the Write enable pin and the 128 KByte ROM itself.
The bottom side has all of the jumpers which are labelled accordingly. If you want the pinout of a CHR ROM, solder the jumpers which are labelled CHR, but if you want to program the chip with your EPROM burner with factory settings, the solder the 010 jumpers and set your programmer in software as a 29F010. Its as easy as that!
I have also reduced the size to 41.91mm x 19.05mm. The filter capacitor is optional since the standard cart will have one immediately next to the power pin of the original mask ROM. The pull up resistor is required unfortunately. Many IC's now-a-days have internal pull-up or down resistors so that pins can be left open or hanging, but the datasheet does not say anything about pull up resistors and this is not a pin we can leave to self-oscillate!
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