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Homemade Z80 Computer Project

Electronics_Wiz

Jan 16, 2018
4
Joined
Jan 16, 2018
Messages
4
Hello everyone! This is my first time posting on this forum. I signed up because I am having a bit of trouble with my Z80 computer ( depicted below the code ). I already put the computer on a perforated board, but the system does not seem to output any correct data. Here is the code that I programmed into EEPROM:
Code:
    org 0x0000
uart_init:
    ld a, 0x80
    out (0x03), a
    ld a, 12
    out(0x00), a
    ld a, 00
    out(0x01), a
    ld a, 0x03
    out(0x03),a
uart_out:
    in a, (0x05)
    bit 5, a
    jp z, uart_out
    ld a, 0x41
    out (0x00), a
    jp uart_out
z80_system_IO.png z80_system_memory.png z80_system_processor.png
 

Electronics_Wiz

Jan 16, 2018
4
Joined
Jan 16, 2018
Messages
4
NOTE: There is a problem I found, that is that two of the CS pins on the UART are tied low when they should be high. This is a simple error in the schematic, but is not present in the system I already have built. Also, the processor seems to be able to activate the UART, as the UART does print data. The only thing is that the data is just a bunch of random characters.
 
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