wraggster
October 22nd, 2013, 12:16
http://hackadaycom.files.wordpress.com/2013/10/chip.jpg?w=620&h=335
Perfection is achieved not when there is nothing more to add, but when there is nothing left to fail. Going by that metric, [Stian]‘s three-chip 6502 homebrew computer (http://jmp.no/blog/3-chip-computer) is the epitome of perfection. It’s a real, working, homebrew retrocomputer using only three chips: a CPU, some RAM, and a microcontroller to bootstrap the computer and provide a video output,
The key to this minimalist build is having the entire boot process controlled by an ATMega16 microcontroller, This interfaces to the 6502 through a dual-port SRAM, a 1 kilobyte Cypress CY7C130 (http://www.cypress.com/?mpn=CY7C130-55PC). This dual-port RAM allows the CPU and microcontroller to access the same bit of memory, making it easy to bootstrap a computer from a bit of AVR code.
Output is provided with [Stian]‘s ATMega video text generator (http://jmp.no/blog/amvtg/) putting a 37×17 characters on any television with an RCA jack. While input isn’t handled yet, [Stian] says it should be possible with his AVR PS/2 keyboard library (http://jmp.no/blog/atps2key/).
While other 6502 homebrew computers such as [Quinn Dunki] Veronica (http://hackaday.com/2013/02/25/veronica-6502-computer-reaches-hello-world-stage/) can reach unparalleled heights of complexity, there is a lot to be said about the minimalism of [Stian]‘s three-chip computer. With some clever coding and a modified parts list, it may well be possible to put a retrocomputer in the hands of everyone with a bare minimum of cost and parts.
http://hackaday.com/2013/10/21/the-most-minimal-homebrew-computer/
Perfection is achieved not when there is nothing more to add, but when there is nothing left to fail. Going by that metric, [Stian]‘s three-chip 6502 homebrew computer (http://jmp.no/blog/3-chip-computer) is the epitome of perfection. It’s a real, working, homebrew retrocomputer using only three chips: a CPU, some RAM, and a microcontroller to bootstrap the computer and provide a video output,
The key to this minimalist build is having the entire boot process controlled by an ATMega16 microcontroller, This interfaces to the 6502 through a dual-port SRAM, a 1 kilobyte Cypress CY7C130 (http://www.cypress.com/?mpn=CY7C130-55PC). This dual-port RAM allows the CPU and microcontroller to access the same bit of memory, making it easy to bootstrap a computer from a bit of AVR code.
Output is provided with [Stian]‘s ATMega video text generator (http://jmp.no/blog/amvtg/) putting a 37×17 characters on any television with an RCA jack. While input isn’t handled yet, [Stian] says it should be possible with his AVR PS/2 keyboard library (http://jmp.no/blog/atps2key/).
While other 6502 homebrew computers such as [Quinn Dunki] Veronica (http://hackaday.com/2013/02/25/veronica-6502-computer-reaches-hello-world-stage/) can reach unparalleled heights of complexity, there is a lot to be said about the minimalism of [Stian]‘s three-chip computer. With some clever coding and a modified parts list, it may well be possible to put a retrocomputer in the hands of everyone with a bare minimum of cost and parts.
http://hackaday.com/2013/10/21/the-most-minimal-homebrew-computer/