05 Dec 2022 - 8 min read
Controller Design: MOV8, MOV16 & MISC Instructions
Way back in 2019 I discussed how you can’t ‘half design a PCB’ and that, as a result, my controller cards already have all the required functionality laid …
21 Dec 2019 - 1 min read
In my last couple of posts I covered off the full design for the controller unit. As the PCBs have now arrived I can get on with soldering up the cards and giving them a test. …
20 Dec 2019 - 4 min read
Controller Design: Schematic & PCBs
In my last couple of posts I finalised the controller schematic designs for the ALU, SETAB, MOV8 and GOTO class of instructions. Now it’s time to bring all those …
07 Dec 2019 - 3 min read
Controller Design: ALU, MOV8 & SETAB Instructions
In my last post I covered off the controller design for the GOTO instruction. Being as I’ve decided to implement the controller on a new set of PCB cards I need to …
30 Nov 2019 - 3 min read
Controller Design: GOTO Instruction
With the sequencer now designed and constructed I’m much closer to getting branching working on my relay computer. The next hurdle is updating the controller cards so …
06 Oct 2019 - 4 min read
In my last post I covered the design for the GOTO opcode which will enable my relay computer to perform branching, loops and so on. Here’s where I got to last time: …
23 Sep 2019 - 7 min read
There’s been a common theme recently in the comments on my YouTube videos … people are ready to see my relay computer gain the power of branching and become a …
27 Mar 2018 - 4 min read
Auxiliary Control Construction
In my last three posts I covered the design of the auxiliary control unit which will ease entering and inspecting programs in the computer’s memory. With the design ‘in the …
07 Feb 2018 - 4 min read
Auxiliary Control Design (Part 3 of 3)
This is the last post in a mini-series of three covering the design of the auxiliary control unit which will ease entering and inspecting programs in the computer’s …
29 Jan 2018 - 12 min read
Auxiliary Control Design (Part 2 of 3)
In my last post I made a start on the auxiliary control design which once completed will make it much easier to load instructions in to memory - effectively it’s a …
24 Jan 2018 - 6 min read
Auxiliary Control Design (Part 1 of 3)
My relay computer is now at the point where it can execute a program in memory without assistance. In order to do that though, of course, the program needs to be loaded into …
16 Jan 2018 - 3 min read
Fetch and Increment - Construction and Test
This is a bit of a landmark moment … at least for the construction of my relay computer. For a long time now my blog posts have been leading up to the point where my …
17 Sep 2017 - 5 min read
Control Design: Fetch and Increment
The design of the computer’s memory, incrementer and program counter are now complete but there’s one last piece of the ‘puzzle’ required to get the …
01 Jan 2016 - 3 min read
Controller Construction: MOV-8, ALU and SETAB
So yea, it’s been a while since my last post … in fact it’s been just over six months. For some reason I decided I didn’t have enough to do in the …
04 Apr 2015 - 6 min read
Control Design: MOV-8, ALU and SETAB (part 2 of 2)
In part one of this two part post I introduced the design of the control relays for each of the MOV-8, ALU and SETAB instructions. With these in hand I can now move on to …
31 Mar 2015 - 9 min read
Control Design: MOV-8, ALU and SETAB (part 1 of 2)
Over the last five posts I’ve been building up the design of a set of cards so that the computer will be able to understand and perform the MOV-8, ALU and SETAB …
19 Sep 2014 - 11 min read
Sequencing & Control Design: Overview
I’ve now got my computer to a state where I can perform ALU operations and push values around the four registers by manually operating the various control lines. …