I believe your code is incomplete. As you specify that the A reg holds the byte value to be printed, your first instruction (TXA) overwrites that value. As it's written, the value in the Y reg would be used. You also don't need the CLC instruction as the carry flag will be set based on the ASL ...

I'm using the following code for that in my monitor program. It is written in Ophis Assembler and for the 6502, so optimization for the 65C02 can be done.

k_wchr is the subroutine to output one character.


;
; print out the 8bit value in A as binary code
; X,Y is preserved, A is destroyed ...

Not sure what version of Ophis you're using, but

CMP #'Q

works fine for me.


...
LDA K_BUFFER ; Get length
CMP #1 ; Is it 1?
BNE ATryImm
LDA K_BUFFER+1 ; Get first char of operand
JSR ToUpper
CMP #'A ; Is it 'A?
BNE ATryImm
LDA #AM_ACCUMULATOR ; Yes, is is accumulator mode
STA AM ...

I'm quite sure that Ophis supports the full set of all 6502 and 65C02 instructions. But you need to set the "-c" commandline parameter to tell Ophis to use the 65C02 instruction set.

Mario.

To question 1) I'm using one of the inexpensive PL2303HX USB2Serial adapter like this one: http://amzn.to/2vdc2xU . They are strong enough to even power a small system and run on 5V TTL level, so you don't have to use a MAX232 to convert to RS-232 voltage levels.
The PL2303HX is directly supported ...

I would also suggest using CoolTerm, it is really easy to use and has some nice features.
Beside the Ophis assembler (be sure to check the " handbook ) I'm using the py65mon for local debugging. You can write your assembler code and test it with this 6502/65C02/65Org16 emulator. It's perfect for ...

I'm also a Mac User and had no problems at all to build my 6502 SBC.
I'm using the ophis assembler, that is written in Python and runs easy on MacOS.
Also KiCad for schematic and pcb development works natively on MacOS.

The built in "screen" command on MacOS can open a serial connection without ...

Hi,
I have built one of Grant Searle's 7-chip 6502 computer based on his modified OSI Rom with Load and Save "nulled"


How did you connect the both ATMega for video and keyboard to the rest of the system? Are they connected to the 6850 ACIA?
If so, how do you distinguish between RS232 and ...

The listings are pictures, so you have to hack it into your editor instead of copy the content and prevent type mistakes.
I'll simply state for small enough examples (for assorted definitions of small), I think typing the code in, mistakes and all, is much better for learning than cut and pasting ...

What I'm missing (beside any company or personal information about the seller) is the lack of any communication possibilities except the I/O ports. Also the software provided seems a problem. The listings are pictures, so you have to hack it into your editor instead of copy the content and prevent ...

Although it says it will time out, when it does so, it seems you don't get a result.

How the timeout works is not clear. Maybe after a defined number of cycles or just depending on the time the code is executed.
But as seen in the description, it will always return the specified memory block at ...

Some people are really creative:

http://www.6502cloud.com/

It seems that the 6502 is now "cloud ready". You can run 6502 code as a cloud service. I'm still thinking about a serious use case, but hey it's really cool

I'm not sure if somebody already mentioned this here. The article is from 2016:

https://scarybeastsecurity.blogspot.de/2016/11/0day-exploit-compromising-linux-desktop.html

A detailed description how 6502 code in a library playing NES sound files is used to cause some trouble on a linux desktop ...

Wow, this thread started exactly (Apr. 05 2013) 4 years ago and still somebody is using this little thing I created just as a simple tool for my project. It turned out that this spin-off has become quite usable in the community.
It's always a good idea to share your work with others it seems ...

Hello everyone,

I found this book Programming the 65816: Including the 6502, 65C02, and 65802 created by WDC on Amazon. Is it worth buying? Has anyone the kindle version of this book. Often the kindle version is only scanned and images and tables are really hard to read.

With best regards,
Mario.