Notes on the Zorro II SID card ------------------------------ 1. The design is very simple - no AutoConfig, only write accesses and a hacked chip select/clock logic. 2. The wiring on the "B" side of the 74HC688 selects the address range of the card. This is currently at $a0xxxx (where Frodo expects is to be). 3. The SID's reset line is not connected to /RESET or /IORST but to /LED to have the possibility to reset the SID independently of the Amiga. This is because some SIDs have problems with the clock signal being pulled down on write access and sometimes one or more envelope generator "crashes" and requires a reset to work properly again. So it is connected to /LED and Frodo cycles the power LED to reset the SID. 4. The whole circuit can be built upon a standard raster board. A custom PCB layout is not required (besides, I don't have one). 5. The "AUDIO OUT" signal can directly be connected to headphones or an amplifier. The "AUDIO IN" signal can be used to mix and filter external audio signals with the SID signal. A note on the programs "EnableSID" and "DisableSID" --------------------------------------------------- As the SID card doesn't use AutoConfig, it's address space will be marked as invalid by the 68040.library on systems with a 68040/060, and the card is not accessable. The EnableSID and DisableSID programs use the 68040/060's transparent translation feature (DTT0) to open the address space and mark it as non-cacheable. Simply run them once to enable resp. to disable access to the SID card (they can only be started from the Shell). The source is included in case you have problems with your MMU setup, so you can modify the programs to fit your system. The DeliTracker player "C64SID" ------------------------------- "C64SID" is what Frodo started out as: A DeliTracker player module for replaying PSID (i.e. PlaySID one-file) music files on the SID card. Simply put it into your "DeliPlayers" directory and enjoy. Be sure to remove "DeliSID" first to make sure that PSID files are opened by C64SID. Christian Bauer