Electronics/Computer Projects

So, I'll be needing an EEPROM programmer in order to actually provide some startup software for my Z80 computer. I intend to make one using a set of shift registers, and a couple optoisolators, so that I can use any microcontroller with 8 I/O pins (7 output, 1 input), assigned as follows: Input: 1 = Data Read Output: 1 = Address/Data Write 2 = Shift 3 = ~WE 4 = ~CE 5 = ~OE 6 = ERASE/VPP (EEPROM/EPROM) 7 = Read Data The design will be as such that any microcontroller that uses either 3.3V, or 5V I/O can safely operate it. An interesting design requirement involves needing to have either 3.3/5V or 12V sent to the ~OE pin of an EEPROM, as the 5V signal is used to read from it, but the 12V is required in order to erase it. A possible solution will be to use a diode to prevent the 12V signal from feeding back to the microcontroller, and an optoisolator to gate the 12V to the same pin during an erase cycle. To obtain the 5V and 12V power rails, I will use a simple regulat

This blog is intended to showcase my electronics and computer projects, as well as educating about related concepts. I currently have an ongoing project consisting of an 8-bit computer I call Zephyr (because I'm bad at coming up with names). Details as follow: CPU: Zilog Z80 rated to 10MHz (Currently running at 625KHz) Memory: 8KB of ROM, 32KB of RAM with room for expansion I/O: Serial Currently it doesn't do anything since I need to create an EEPROM programmer, which I plan to make using shift registers and a controller of some variety. I also have plans to create another 8-bit computer project called CosNaut (Again, bad at names) using an RCA 1802 'COSMAC' CPU, though anything else is not set in stone. Will post updates as necessary.