Over time, and particularly in recent years, we’ve observed heaps of single-board retrocomputer builds. That’s high-quality with us — the extra, the merrier. However all of them begin to run in combination somewhat, with little to differentiate between them. Now not so this about-as-compact-as-possible 6502 pc that matches on a unmarried breadboard.
Now, while you do the mathematics, it sort of feels like there’s no approach that [Anders Nielsen] would were ready to suit even a minimum chipset onto a normal solderless breadboard. The 40-pin 6502 on my own takes up just about two-thirds of the connections to be had; upload in similarly massive however vital chips just like the 6522 interface adapter, ROM and RAM chips, and a few strengthen ICs, and one breadboard isn’t going to chop it. Fortunately, some frugal engineers at MOS again within the 70s got here up with the 6507, a variant at the 6502 in a 28-pin DIP. The opposite key to this construct is the 6532 RAM-I/O-timer chip or RIOT, which places a tiny quantity of RAM and a few IO strains on a unmarried 40-pin DIP. Along side a 28-pin ROM, a 14-pin hex inverter, and a bit crystal oscillator, all of the chipset simply slightly suits on a unmarried breadboard.
However what can this minimalist 6502 in reality do? As you’ll be able to see within the video under, anything else a 555 timer can do, and possibly a bit bit extra. That’s no longer a dig, after all — [Anders] in reality calls out his preliminary blinkenlight utility as a bit greater than a glorified 555, and in reality comes up with a slightly extra advanced utility simply to end up the purpose. The attention-grabbing section this is coping with the restrictions imposed through the restricted assets to be had in this system.
We’re taking a look ahead to no matter comes subsequent for this suave construct. It’s arduous to peer how one of the most plans [Anders] has for it is going to nonetheless have compatibility on a unmarried breadboard, although — this stuff have a tendency to unfold out as they cross.