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h0m3
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Im building a VGA (640x480@60Hz) adapter for my homebrew project but i dont have enought memory to store a framebuffer. Since im using 8 bit memory i plan to do 8 bit color, but 8 colors would be enought for my project.

How is the most efficient way to implement a character mask (8x8 pixels) using only memory and TTL? I was thinking about using a memory bank (6264) to store the character mask, another bank linked to that to select wich mask i want to use in a sequency using binary counters. Then using a PISO Shift Register (74166) at 25MHz to feed a multiplexer (74157) that selects background or foreground color stored at another memory bank. But this seems overcomplicated.

Since only the 74166 and the 74157 would be running at 25MHz i can get off with HC ones? Or better to run with another model (they are harder to find here).

I want to avoid FPGAs. Use only TTL, SRAM and microcontrollers.

Im building a VGA (640x480@60Hz) adapter for my homebrew project but i dont have enought memory to store a framebuffer. Since im using 8 bit memory i plan to do 8 bit color, but 8 colors would be enought for my project.

How is the most efficient way to implement a character mask (8x8 pixels) using only memory and TTL? I was thinking about using a memory bank (6264) to store the character mask, another bank linked to that to select wich mask i want to use in a sequency using binary counters. Then using a PISO Shift Register (74166) at 25MHz to feed a multiplexer (74157) that selects background or foreground color stored at another memory bank. But this seems overcomplicated.

I want to avoid FPGAs. Use only TTL, SRAM and microcontrollers.

Im building a VGA (640x480@60Hz) adapter for my homebrew project but i dont have enought memory to store a framebuffer. Since im using 8 bit memory i plan to do 8 bit color, but 8 colors would be enought for my project.

How is the most efficient way to implement a character mask (8x8 pixels) using only memory and TTL? I was thinking about using a memory bank (6264) to store the character mask, another bank linked to that to select wich mask i want to use in a sequency using binary counters. Then using a PISO Shift Register (74166) at 25MHz to feed a multiplexer (74157) that selects background or foreground color stored at another memory bank. But this seems overcomplicated.

Since only the 74166 and the 74157 would be running at 25MHz i can get off with HC ones? Or better to run with another model (they are harder to find here).

I want to avoid FPGAs. Use only TTL, SRAM and microcontrollers.

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h0m3
  • 85
  • 1
  • 7

Character mask VGA display

Im building a VGA (640x480@60Hz) adapter for my homebrew project but i dont have enought memory to store a framebuffer. Since im using 8 bit memory i plan to do 8 bit color, but 8 colors would be enought for my project.

How is the most efficient way to implement a character mask (8x8 pixels) using only memory and TTL? I was thinking about using a memory bank (6264) to store the character mask, another bank linked to that to select wich mask i want to use in a sequency using binary counters. Then using a PISO Shift Register (74166) at 25MHz to feed a multiplexer (74157) that selects background or foreground color stored at another memory bank. But this seems overcomplicated.

I want to avoid FPGAs. Use only TTL, SRAM and microcontrollers.