TTL Computer II #10 - Monitor & Keyboard

My 8 bit TTL retro computer build using Digital simulation and modular PCB manufacturing.
I want to thank ‪@PHILG2864‬ for sharing his Z80 monitor code for my Z80 computer some time ago. I have adapted Phil's monitor for use with TTL Computer II.

[@PHILG2864]

Hey Charlie, many thanks for the mention and I'm pleased to have helped in a very small way
with the monitor code :-) and thank you for featuring my channel, I'm no videographer and mine is a very amateurish bunch of hobby videos so I'm really happy to have been noticed!
Cheers - Phil_G

[@CharliesChips]

Thanks Phil and all the same can be said of my channel!

[@terryjames8238]

I have been following this TTL Computer build and constructed each component from video #1. The item i am stuck on is the 32K Ram. I used the 8K ram that is included in the software and increased the address to 15 bits. Does this expand the RAM size or do I need to use 4 x 8K ram chips connected together? Will you be posting a link to the ROM code and making it available for download?

[@CharliesChips]

Hey Terry thanks. I am tickled to hear someone is duplicating the build. Yes, that is what I did also. Took the 8k ram and expanded the address bits. I can't post a picture here so have a look at my community section and I will post a picture of my modification along with a note on trying to make the project available. Charlie.

[@CharliesChips]

Hi Terry I should be able to release a full version of the Digital project after next weeks video is published.

[@terryjames8238]

That will be fantastic. I have completed the build exactly following your videos. I'm having a fault on running the computer with B7 on the ALU chip. I've opened up the ALU and it runs correctly. The error I'm getting is, No output connected to B7 in tunnel (B7) state of wire is undefined ?? Any ideas??

[@CharliesChips]

@@terryjames8238 Its hard to say. Check that all the wires are connected (sometimes they are just short of the pin). Make sure you did not use a tunnel when you intended an input. Make sure all your tunnels are named correctly. Hope that helps.

[@terryjames8238]

I've solved that issue and it was the incorrect label of the tunnels. Both B and A were labeled as B and A. Should of been L and R bus labels. I am error correcting at the moment step by step. Hopefully will get it sorted soon.