In this project, I will show you how to make a wireless circuit using photoresistor, LM741 Op-Amp IC and 4017 decade counter. When you take your hand over the photoresistor while the switch is off, it will turn the appliance on. For the second time,...
One of my motivations is to also get it to work on my 8085 SBC. It turns out to be fairly straightforward. I have a hacked asz80 that flags instructions that are not in the 8080 subset. Here is the output of a grep '^[a-z]' efz80.lst a 0105 ED 79 [12]...
There are various well known and documented patterns and best practices to create FSM (finite state machine) designs that work well on FPGAs. However from what I have seen, not much in terms of how to have a simple, good microcode pattern. One could...
This component serves 2 purposes:- illustrates that microcoding can easily be used for non-CPU circuits such as display, I/O, disk, or any other custom controllers- useful in the project to trace main CPU instructions executing for debugging or illustration...
In the previous log it was identified that SIMPL would be hosted as a virtual machine running from ROM on the chosen microcontroller.In this log I explore the practicalities of creating a simulated stack machine running on a Teensy 4.0 and programmed...
# 2022-09-06 Tracing the function board This board holds 48 keys. Function board, front Function board, back detail Arbitrarily numbering things: function clusters cluster A-D as seen from left to right from the frontNote: cluster E is located on...
The main point of this project was to recreate a working CPU by following a technical document from 1978, illustrate micro-programming in a practical way and recreate the ICs (especially Am29XX) from the era in a FPGA. Maybe not the best (which...
I've been working on this turret off and on for over 5 years. I hit a huge milestone on May 29th 2019. The turret successfully tracked and shot down a Tiny Whoop (micro drone)! The next day I set the turret up in my living room and captured some footage...
Microcoding as a technique is very much aligned with "test-driven development" concept. Essentially it means first to build the scaffolding needed to test the circuit, and then the circuit itself. Just like the microcoding itself, the advantage here...
Before getting back to general architecture, let's talk about Super Mode, because that's pretty fundamental to the memory protection scheme. This is going to be quite a long brain dump of where I've got to in thinking about this. I'll try to add...
Automatic bed leveling has become a standard feature in the last 2 years & has standardized on hall effect sensor pin testers. Hall effect sensors can measure distance down to the .1mm precision required. The lion kingdom got a cheaper 3dtouch...
The calculator/CPU cannot function on its own, without being embedded in a system that gives it the I/O, clock, outside hardware connections etc. on the FPGA board. The top-level object that does this is sys_sbc8816.vhd (simplified schema, bolded...
This little computer ultimately is going to be a standalone system. I am working towards this goal to hopefully one day cut the cord and get rid of the need for a PC as a host computer / cross-development platform. In the recent months I have been working...
In this project, instead of using a standard embedded processor and programming it to execute 3 tasks at hand (parsing HEX character stream, generating HEX character stream, and writing character stream to video RAM driving VGA), I created 3 independent...