Squeezing A Minimalist 6502 Retrocomputer Onto A Single Breadboard

About the yrs, and particularly currently, we’ve witnessed tons of one-board retrocomputer builds. That’s fantastic with us — the far more, the merrier. But they all start off to operate together a bit, with very little to distinguish between them. Not so this about-as-compact-as-attainable 6502 laptop that fits on a solitary breadboard.

Now, when you do the math, it looks like there is no way that [Anders Nielsen] would have been able to fit even a minimum chipset onto a conventional solderless breadboard. The 40-pin 6502 alone normally takes up nearly two-thirds of the connections out there add in equally significant but essential chips like the 6522 interface adapter, ROM and RAM chips, and some assist ICs, and a person breadboard is not heading to reduce it. The good news is, some frugal engineers at MOS back in the 70s came up with the 6507, a variant on the 6502 in a 28-pin DIP. The other vital to this develop is the 6532 RAM-I/O-timer chip or RIOT, which places a small sum of RAM and some IO lines on a single 40-pin DIP. Alongside with a 28-pin ROM, a 14-pin hex inverter, and a tiny crystal oscillator, the complete chipset just hardly fits on a single breadboard.

But what can this minimalist 6502 essentially do? As you can see in the online video beneath, everything a 555 timer can do, and probably a little little bit much more. That is not a dig, of course — [Anders] basically calls out his first blinkenlight application as a minimal a lot more than a glorified 555, and truly will come up with a marginally additional sophisticated software just to verify the level. The interesting component right here is dealing with the constraints imposed by the constrained resources offered on this device.

We’re seeking ahead to what ever comes upcoming for this intelligent construct. It is challenging to see how some of the designs [Anders] has for it will still fit on a single breadboard, though — these matters have a tendency to distribute out as they go.