8bitnews

One of the most interesting news of the last week comes from David Schor, author for WikiChip Fuse. And it's once again about the 6502 - or rather a modern incarnation of the 8-bit CPU.

The reasons why processors like the 6502 are still being built almost 50 years after their release, are certainly manyfold. Manageable complexity, extremely low power consumption, relatively small netlist and an enormous amount of software and toolchains available. Western Design Center still produces a modern offshoot of the CPU successfully and in quantities.

However, the really interesting innovation we are talking about here, is a completely different one and is called FlexlogIC.

The Flex6502 is a fully functional processor on a flexible substrate just 30 μm thick. Scientists at the University of KU Leuven developed the technology together with partners imec and PragmatIC Semi and call the result "TFT-based processors".

There are certainly plenty of application scenarios for it, the question remains whether and when the technology will be commercially available.

You have some time to spare? Very well. You're going to need it. What Steven Hugg has been compiling since 2017 touches on a whole bunch of 8-bit icons and unfortunately only landed on our screen last week.

On his site 8bitworkshop, Steven offers 4 on-topic books as well as lots of detailed knowledge on the usual suspects: VCS, NES, Apple ][+, ColecoVision, MSX but also Arcade systems like VIC Dual, Midway 8080 or Galaxian.

But it gets really meaty 🥩 when you start the JS based IDE. Here you can emulate not only the mentioned systems, but a lot more. In addition you can run Verilog directly in an emulator.

For each supported platform there is a whole set of examples, whose source you can edit and try out directly in the browser. In combination with Steven's books - for example Designing Video Game Hardware in Verilog - the whole thing totally makes sense. Fantastic learning resource.

Unfortunately we missed it completely, but definitely the recommendation of the week for all those who want to learn something old new.

From time to time the schematic of PONG appears somewhere in the net. Interesting because the original did not need a CPU but was based on an optimized number of discrete logic ICs only.

Not too many people know what to do with the schematic alone, but if you separate the individual modules and make them work in a circuit simulation, it gets really interesting.

That's exactly what Paul Falstad did, and he also made the results available online here.

If you are developing hardware yourself, you certainly won't find a tutorial here. But the ideas in PONG's implementation are an excellent basis for your own experiments. And the visual circuit simulation helps to understand more complex circuits. Well done.

In any case worth a look.

IoT and the Apple // line don't sound like something that would be compatible in any way. Nathanial Hendler thought to change just that. 

His Apple2Idiot board is actually a simple idea. Take a dual-ported RAM, an ESP32, put both on an expansion card and off you go. ⚡️

The Apple then simply writes and reads to the RAM and the ESP32 does whatever it likes with the contents. Kind of like memory-based IO with total freedom to do whatever you want with it. For example, sending a Slack message, retrieving data from HTTP-based API's, or doing all the other fun things an ESP32 should be able to get up to.

Nathanials GitHub repo comes with a number of examples, and you can use those to for your own experiments. A simple and ingenious idea. The only question is where to get dual-ported RAM today? 🤔

And since we're on the subject of electronics, here's another little gem that shouldn't be missing from any link collection. 

Bill Bowden has compiled a whole army of different circuits, which can be useful every now and then. For each of them there is a schematic and a short explanation.

Whether the whole thing is useful depends entirely on the reader, so decide for yourself.

Only drawback: Comic Sans 😄 - (I thought the font would be banned today on pain of death).

James Sharman has been criminally neglected so far. This has to be changed, because the good man has - probably inspired by Ben Eater - startet to implement his own CPU architecture about 3 years ago. 

In contrast to others, however, James has seen the thing through to the end. And in his current video #100 he not only draws a conclusion. He compares his build it to other 8-bit systems, and the results are surprisingly interesting.

If you enjoyed Ben Eater's 8-bit CPU series, you're in pretty good hands with James, as he not only takes the initial SAP architecture much further, but tackles very classic challenges like CPU pipelining, UART, VGA, audio, and others.

His style is his own, but the videos are definitely worth watching.