my suggestion is to build at least one SID core with the PIC16F as a reference. Since the current JDM programmer possibly needs some modifications to supply the PIC18F, the ramp-up of the new design can be pretty difficult w/o electronic knowledge. Hope that it will get easier when enough experienced people tried it.
LTC: it’s only an electronic extension, sure it works also with the SID. You can also connect the J11:MI and J11:Vs pins of the cores w/o MIDI interface to J11:MI/J11:Vs of the core with MIDI interface together. On this way the MI pins acts as “MIDI Through”. Additional amplifiers (74HC00) are not required as long as the additional cores are not stuffed with optocouplers.
For a better understanding:
J11:MI is the digital MIDI In which goes to the Rx pin of the PIC. It can be used to supply the Rx (digital MIDI In) pin if no optocoupler is connected, or to forward the MIDI stream which goes through the optocoupler (digital MIDI Through)
J11:MO is the digital MIDI Out which comes from the Tx pin of the PIC. It can be used to chain MIDI modules (MIDI Out 1st core -> MIDI In 2nd core). This method is not supported by the SID module, because it requires an internal MIDI Merger.
If you wire the MI or MO pin from one to another core, the ground pins (J11:Vs) have to be connected also.
LEDs can be connected to both pins: J11:MI for MIDI In LED, J11:MO for MIDI Out LED - but they require an amplifier which can be found on the LTC module.
I realized it on the same way on the first days. Later I built my SIDs into two seperate boxes, so that I’m able to lend one to friends and to use the other for my daily pleasure
A particular variation is the way I realized the MIDI In - it comes with an integrated MIDI Thru on the outer pins, also know as “Extended MIDI In” (Atari ST). Here a schematic:
no, the extended MIDI In is not standardized, but it’s usefull I only know it from the Atari ST.
The 15V input is ok for both modules - since no LCD, no pots and no LEDs are connected to the core module, the 7805 will not get too hot like on common applications.
