Folks! Good news.

It worked. The problem was in the ACIA baudrate. I use a 1.8432 MHz crystal connected to ACIA ports 6 and 7. Port 7 before was connected to a capacitor and it was on GND. I removed the capacitor and it worked. The baudrate of 9600 was accurate!

: D: D: D: D: D

A long time ago I ...

Hello guys. It's me one more time.

I checked the cables, looped the TX and RX and I can receive the sent characters correctly.

I'm using a baudrate of 9600. Below is the logical analysis of when I press some character on the keyboard. Look through the zero channel of the analyzer that nothing ...

How can I do this? Put a little dead time between bytes?

Hello guys. It's me again.

I came back with a new 6502 processor and by the time I communicated with the ACIA (6551) it worked correctly. Now I'm trying to do a serial output with "Hello World!". I'm trying to use Putty but I do not see anything in the text output. Using the logic analyzer, every ...

Hi guys,

I was thinking here, the 6502 processor has as the RESET VECTOR the address FFFC (1111 1111 1111 1100) and FFFD (1111 1111 1111 1101), both needing 16 bits for correct addressing?

Since 6507 has only 12 bits of address, it is correct to state that in this case, the RESET VECTOR would be ...

You haven't answered all the questions, hitlp. What do you use to load the AE29f2008-12 flash ROM with the file produced by the assembler? I'd like to ensure that that tool is being directed properly -- that you're telling it to do the right thing.

Hi Dr. Jefyll. I forgot to answer. I use the ...

The 6551 has /CS1 (active low) and CS0 (active high). Presumably you've tied CS0 high?

Yes .. I put CS0 on VCC.


So you have an assembled object file. How is that getting into the ROM? And given that you have a 2KB address range mapped to the ROM, why is your image 8KB long?

It is a good ...

More questions. Sorry! :)

You can ask all questions that you need. lol

Except the AE29f2008-12 has one more address input than the AT28C256, is that right? Just checking.

Actually the AE29f2008-12 has 3 more address input that the AT28C256. AE29f2008-12 have A15, A16 and A17. All those pins I ...

I tied A13, A14 and A15 at low (GND).

I tried now and got a similar garbage.

What values may need to be changed?

Hello guys,

Well answering the questions, I tested with baudrate of 1200 and 9600 and kept getting trash on the way out. I am using as clock source, a crystal of 1.8432 MHz connected in pins 6 and 7 of 6551.

Answering Dr Jefyll, since the 6507 only has addressing up to A12, I connected this port ...

Hello guys,

I have some news about my project. While I can not get a real 6502, I'm using 6507 taken from an old Atari. The processor is responding correctly, for example when I use the data bus as "EA" (NOP). I made the connection to the EEPROM and it worked correctly.

Now, following the project ...

Hello guys.

It's me again and I'm just totally stuck. I reset all my circuit and simply when I set up the data bus to run NOP forever, A0 stays at 500 Hz. That is, it is not consuming 2 CPU cycles. Is it possible for this processor to have a "cache" of execution?

If you can also put a link where ...

Hello guys.

It's me again and I'm just totally stuck. I reset all my circuit and simply when I set up the data bus to run NOP forever, A0 stays at 500 Hz. That is, it is not consuming 2 CPU cycles. Is it possible for this processor to have a "cache" of execution?

If you can also put a link where I ...