◆ SD Music card

SD Music card compatibility issue

이안김 2017. 7. 20. 22:36

Dear friends,


I developed the SD Music card to enhance old mockingboard of APPLE II.

In fact, I love this approach and sound quality.

In that version,

I replaced all electrolytic capacitors to tantalum capacitors for better sound quality and life.

And used RC filter on output AMP and some more improved.


But, It has compatibility issue following part's LOT#. It means that some chips works on some model with some software running.

In fact, After made this board, I've tested it on my APPLE //e and ][+ with SKYFOX and Ultima 4,5 before to ship. All fine then I sent it.

It works fine on APPLE //e even IIGS with Mockingboard patch.

But, I found it didn't work some software and some of APPLE ][+ model.


I really having hard time to find this cause...

It is happen because of the 6522 timing doesn't match well on APPLE II with 6502 CPU.

With some more research, I could find good way to overcome this issue and quickly applied on new PCB for SD Music card.

Sample card ordered and waiting for this.

On the CPLD testing, It works perfect on my APPLE //e and ][+ with all softwares.

and will test some of APPLE ][+ clones..

Please wait for some weeks for new board.

I will post when I have new board with testing results.


** NOTICE **

If you are not happy with your old version of SD Music card due to compatible issue, I will replace your card to new one. 

Please ask me the address and send your card with sure way.

When I received it, I will send new board for you. 


* I will test all arrived board, 

it if it failed to work with some another reason, It will be charged some costs,

Good working conditioned board will be replaced without return shipping charge.


Thank you very much;

Ian Kim