These days, a serial adapter is widely understood as a way to convert a TTL serial stream to a more "modern" (read: more pointlessly complicated) protocol. And that's what the Central Scrutinizer does in its most basic incarnation by converting the serial...
The Simon project was hand assembled and hand typed. That was a lot of fun and was rewarding. However, you quickly hit the limit of what can reasonably be done that way. Several days after posting it on Hackaday, we had a brief...
While it's fun to play with a keypad, GPIOs, and 7 segment displays, you really can't do much without some more RAM. In particular, I wanted to be able to run some vintage Altair software and do the normal "computery" things. So, after...
2023-10-14 After a lot of reading and feeling like D.P. Gumby saying "My brain hurts!", I've now got a better grasp of what is going on. I started from Andy's ZX81 logic in TTL. You might think "surely that is just a ZX80" but it is isn't. The ZX81 had...
When I started working in 1986, companies usually stocked a wide range of 74LS logic chips. Programmable logic in the form of PAL chips had started to make life a lot easier by mopping up most of the small-scale logic. This reduced the amount of...
I was quite happy with how Phase 1 of my JJ65C02 project ended up. I had a pretty solid miniOS coded up. I had ported EHBasic to not only my system but also to the (more robust) ca65 development system, and removed hard-coded addresses allowing it to...
Now that a lot of the hardware work has been done on the latest revision of JJ65C02, it's time to circle back and dive into the software side of things. My previous logs have described the updates to my miniOS for the system, and the integration with...
Let's look at the central control circuitry next. If we take a look at the subsystem breakdown in BJR_LOG_02, we can see the central control circuit already has it's inputs and outputs defined. The following figure is a context diagram, which shows the...
BACKGROUND While physical serial ports are becoming increasingly rare on modern PCs, the serial port has persisted thanks to virtual serial port adaptors like FT232 or CP2102-based USB to UART converters. These converters play crucial...
We have been testing WiSer in various scenarios. One such important test is the actual RF range of WiSer devices. The purpose of the test was to determine the physical distance from which WiSer devices can reliably communicate with each other. HOW TO...
While numerous development boards exist in the market, the Raspberry Pi stands as the go-to device for hobbyists and tinkerers. And why not? It's remarkably straightforward to connect a Raspberry Pi to an HDMI display, attach a keyboard and mouse, and...
In embedded systems, any ESP32 development board is a formidable platform for developers and enthusiasts alike. But what if we told you there's a way to enhance the programming experience, eliminating the need for cumbersome cables and providing the...
The 'Find Pair' button on WiSer-USB device is not just about locating your paired WiSer devices; it holds additional functionalities, such as toggling the RTS/CTS hardware flow control. Let's discover the workings of the 'Find Pair' button. Identifying...
We're enabling Broadcast Mode on WiSer! This significant upgrade opens up a world of possibilities for users with multiple host systems and embedded devices in their environment. So what does it do? The Broadcast Mode in WiSer enables wireless serial...
The IQR83 main computer communicates with the outside world through the obscure TMS9900 "CRU" interface. CRU is short for "Communications Register Unit". The CRU interface has been described as 4096 wires but it is actually one input pin, one output...