When designing my register file, I kept in mind that I'd want this to be implementable in (mostly) TTL. I wanted to keep programmable logic to a minimum. But I also wanted to have a useful, flexible architecture, which would be...
I finally overcame inertia, took advantage of some reasonably nice weather and built up two frames so I could do some testing during the winter season. Testing in summer, at least here in Colorado, is easy. Weather is fine and there is an...
In the southeastern United States, the ring-tone chirping of crickets at night is accompanied by a percussive rattle that's common from mid-summer through fall. Where I live in northwestern Virginia, the dominant percussionist in our nighttime chorus...
After printing a few more hexagonal pieces, I quickly learned that joining them with bolts was simply unsustainable. Aside from physical injuries due to pieces snapping when I can't get them positioned just so, I realized that snap-fits are...
An early log talked about 16 possible video modes. This is still the case, but a lot has changed since then. The following should clarify what the current modes are and how they are supported. The 16 modes are defined by 4 bits with the following states:...
This post will meander quite a bit; I got back from my trip safely and have started working on this project again. I also started a new job at a local maker space, one of my job perks is the usage of their space. The access to a shop again is rather...
With the Input, Output, and Core Panels done it was time to tackle something a little more challenging, the ALU. Since I had a small stash of signal relays burning a hole in the bottom of my parts bin (graciously donated to my makerspace Kwartzlab...
Time for another update. Mind you, at this point I am not documenting work that was already done in the past, but am following my actual development in real time. Therefore updates will be spaced much further apart, depending on how much time I can devote...
As noted above, the EXTEST instruction is not safe if you do not have the electronic schematic. For example, some unused pins can be connected to ground. Forced change of the state of such pins to 0 or 1, using the EXTEST command, can lead to...
Boian Mitov1:04 PMThank you @Usagi Electric (David) and @Dan Maloney :-) Usagi Electric (David)1:05 PMThank you all for the excellent discussion! I don't actually have any plans though, so I'll be hanging around a bit more, haha And although we have...
Summary I had a 'hard drive' (really, SD card) crash, and now I am in data recovery mode. I will have to rebuild the server. I will lick my wounds in the modern, containerized, way. Deets Youth I have run a home server for decades -- I assume...
Timings are crucial! Let's check if we can go with a 4MHz clock using 70nS SRAM and the EEPROM. CPU timings First of all I want to try to recap CPU informations about timings from the WDC W65c02s datasheet. In the picture: PHI2: at 4MHz clock...
This winter we’ve been experimenting with our engraving process to lock down the best methods for different materials & cups. In this series I’ll be sharing some interesting tips we learned along the way in a small easily digestible format. First enjoy...
Software components Vintagephone software is composed by different parts. We have some functions to control the bells, the rotary encoder and the switch. We have functions that handle the clock methods, for setting the time and check the timer for...
Although this is an on-going project, I have been working on it for over a year before publishing anything, so I'll try and capture some of my approach, experiences and lessons learnt to bring this site up to date. One thing I have been doing over the...