Rev. 2.0 boards and what’s next 4

Rev. 2.0 boards and what's next
This is how a box full of printed circuit boards looks like. That’s 30 boards total – memory card and 5 CPU cards, each in 5 copies nicely sealed in plastic. They have been sitting in my drawer since last Summer. In the meantime I have undergone a little surgery, moved to a new house, ...

Works like a charm 9

As announced last time, I powered up the CPU. In all honesty, I was expecting to see a blank screen and was prepared to spend some quality debugging time in front of a scope and logic analyzer, but was positively surprised to see that the CPU worked on the very first attempt. I even let ...

EPROM emulator hacked and working

EPROM emulator hacked and working
The EPROM emulator I mentioned in my last post now works with the memory board. Making it work was an easy task and required a few simple hacks in hardware and software. Now I have a convenient and reliable development environment based on real hardware, and free of the hassle of EEPROM programming. I know ...

Hardware testing completed 3

Hardware testing completed
Yes – the wire wrapped CPU prototype now passes all tests. Since I finished construction a couple of months ago I have been trying to eliminate all outstanding logic bugs and make the machine more stable. Only at this point I am confident enough to declare the preliminary QA phase completed and happily spread this ...

My bookshelf

My bookshelf
A while ago I told a colleague at work that I build a custom CPU in my free time. His first question was – how come I still have free time? Considering our type of work, this was the most obvious first question to ask – currently I can only spendfew hours each weekend to ...

It works! 1

It works!
Finally! It’s been 532 days (or 1 year, 5 months and 24 days) since my very first post here, and today I have a real, working machine, able to run programs and perform useful computations. Last night my CPU successfully executed the fibonacci program from this post from May (all homebrew CPU guys run fibonacci, right?). The code snippet ...