Hi
Read through this forum for many months, to get supplement to my class studies. Unfortunately, I am now completely surrendering myself to your guys input, because I am truly out of breath and energy to push through any further with my lab project.
Here is my class' project objective:
--Design and implement the hardware and software of a simple EEPROM programmer with common TTL IC's that are mostly available. The EEPROM program is designed to connect to a standard PC's parallel printer port and work independent of processors speed. An assembly program to read and write data from/to the EEPROM programmer from a PC is also to be developed.
I have hard wired a schematic, using the following devices:
32Kx8 EEPROm ( ATC28C256)
4 74LS374
74LS257 Mux
74LS138 Decoder
Printer Cable DB25
the DB25
-- Base +0 address will be used to send output data that are used as address signals to EEPROM, data to EEPROM, and control signals to EEPROM
--BASE+1 address will be used to read 4-bit data from EEPROM
--BASE+2 address will be used to send 4-bit output to use as control and input signals of 74LS138 and select signals to 74LS257 MUX
Welll...
the hardwiring is pretty much taken care because we were given a general schematic and I have completed the actual wiring on my breadboard.
However, using the DOS system, I am completely stuck on how to read,write to the EEPROM. Data is to be verified correct, in our case , I will be using LED's.
But if you guys can figure a way to use DOS to read/write through the DB25, I am open to ideas.
I have spent the last few days trying to get this work, and have always failed at writing the assembly program.
Thanks.
Read through this forum for many months, to get supplement to my class studies. Unfortunately, I am now completely surrendering myself to your guys input, because I am truly out of breath and energy to push through any further with my lab project.
Here is my class' project objective:
--Design and implement the hardware and software of a simple EEPROM programmer with common TTL IC's that are mostly available. The EEPROM program is designed to connect to a standard PC's parallel printer port and work independent of processors speed. An assembly program to read and write data from/to the EEPROM programmer from a PC is also to be developed.
I have hard wired a schematic, using the following devices:
32Kx8 EEPROm ( ATC28C256)
4 74LS374
74LS257 Mux
74LS138 Decoder
Printer Cable DB25
the DB25
-- Base +0 address will be used to send output data that are used as address signals to EEPROM, data to EEPROM, and control signals to EEPROM
--BASE+1 address will be used to read 4-bit data from EEPROM
--BASE+2 address will be used to send 4-bit output to use as control and input signals of 74LS138 and select signals to 74LS257 MUX
Welll...
the hardwiring is pretty much taken care because we were given a general schematic and I have completed the actual wiring on my breadboard.
However, using the DOS system, I am completely stuck on how to read,write to the EEPROM. Data is to be verified correct, in our case , I will be using LED's.
But if you guys can figure a way to use DOS to read/write through the DB25, I am open to ideas.
I have spent the last few days trying to get this work, and have always failed at writing the assembly program.
Thanks.