Stuff what I did
Time to upgrade some of my binary Blinkenlights plug-ins to 7-segment LED hexadecimal versions. In the design of my Hol-1 8-bit CPU I have been leaving rows of pin headers for the attachment of LED indicators. Mainly because you can never have enough Blinkenlights twinkling on a homebrew computer but also because they have their […]
Following on from the Combinational Logic Tutor this next item is on the next rung up the computing evolutionary ladder. To explain I’d better start with combinational vs sequential logic theory. Combinational and Sequential Logic As seen in my previous post, connect the different logic gates and the Combinational Logic Tutor’s output is generally* a […]
A COMPUKIT Combinational Logic Tutor ascends to Silicon Heaven. My Own Silicon Heaven For some variety and whilst I’m stuck at home under corona virus lock-down I thought I’d start to catalogue my old computer and test equipment collection. I’ll tag these as ‘Silicon Heaven’ because, according to Red Dwarf, that’s where electronic equipment goes […]
Improving the clock signal on my 8-bit “Hol-1” CPU. As my homebrew 8-bit CPU takes shape I find I’m continually fighting temptation to re-design the boards that have been created so far. I realise though that that would be unproductive as no sooner had I created a version 2 of a board then I’d get […]
Building an Arithmetic & Logic Unit (ALU) with TTL logic. Recap: My quest to build an 8-bit central processing unit (CPU) from transistor transistor logic chips (TTL) continues. This initial venture into CPU design being very much guided by Ben Eater’s video tutorials for a computer built on breadboards. Please refer to Ben’s videos for […]
Building CPU registers with TTL logic and some blinkenlights. Recap: Previously I posted about my quest to build a computer’s central processing unit (CPU) from transistor transistor logic chips (TTL). This initial venture into CPU design being very much guided by Ben Eater’s video tutorials for a computer built on breadboards. Please refer to Ben’s […]
Building a CPU clock and controller from 555 timers and TTL logic. Update: Please note my later post which contains an improvement to this TTL clock signal generator. Why?: Back in 2015 when I posted an item on Logic Buffers I intended to produce follow-up posts covering common logic chips. Producing each in a simple […]
With computer programming I’m drawn toward low level languages. Somehow hoping to understand what all the 1’s and 0’s are doing to truly feel in control of the computer. An understanding of those basic building blocks is really important even though using them in most projects would be too time consuming and error prone. With […]