11/07/2019 at 08:42 •
The good news is: the first bit of the Q register and the ALU have been wired and they're working! Also proving that the more efficient ALU designs are a reality!
I tested for convenience the full adder and for the logic part the NAND operation, but all other logic ones are straightforward to see operating.
Below for example 1 of the Q register is added to 1 of the bus and a 1 carry in, resulting in a one on a "flying" bit of the R register and a carry out on second bit (note that relay view is upside down):
The bad news is that mounting it with fastons as I did is extremely difficult with "dense" relay utilization...
10/28/2019 at 20:08 •
The frame start to get populated:
50 might be a little number of relays but surely is already providing quite an intricate mess of wires and a lot of headaches if not properly planned (and even if properly planned): at least let's try to manage at best!
Following a bit more detailed overall schema of the PC (more details of the various circuits will come in later posts):
And below a tentative to put some order between units in the frame:
As of last image a drawing guide for the wiring of the first bit of the ALU (the famous "no dollars" one of @roelh):
(the full layout of the MY4NJ can be found in first project log)
10/28/2019 at 07:05 •
First things first: let's start to see if the relays are properly working...
For the purpose I built a little tester rig:
Result? Bad. Out of the 62 relays I've found that 13 of them work unreliably and 3 not working properly at all. Partly good news is anyway that I've 46 remaining that seems working, let's see.
In the meantime I built also a frame to keep the relays of the mounted computer. Here the last assembly step:
10/20/2019 at 17:33 •
Relays finally arrived, and now it's time to start build the computer!
I bought around 60 of them, hoping even to spare few with 8bit implementation... In reality I might spare even more realizing at least the first version with 4bit word lenght: easier to assemble, to debug, and anyway reaching all goals of the project, and "expanding" it later. I will decide building it. Anyway the design allows for the word to be any multiple of 4bit (e.g. 8, 16, 32 and even 64 bits) since there is no delay accumulation increasing the word size.
The relays number in this moment do not account for the memory. For which I will probaly buy a different type (trough hole) for easyness of assembly with condenser (if the current design will work).