wbc wrote:Another question here - AFAIK ROM legal status is still unclear now, so prototypes will not be equipped with onboard ROM I guess
The legal status of the official 1 MiB ROM is very much known. With no less than three companies having copyrights on the data in that ROM, it would be just about impossible for a small community project to obtain a license to use that exact ROM image. Even if they were willing to offer a license, we likely don't have the budget for it to be worth their time to even talk to us.
There could be some chance of being able to legally use the 4 MiB set from Eye & I, but when I mentioned it recently, nobody expressed any interest in that option or in even asking them again. So, as it stands, we cannot distribute any of those instrument banks.
Since this is a solder-it-yourself project, there will be no ROM or flash included at all. You get only the card and InterWave IC; what you put in the ROM footprint, and what data you program into it, is your business. Currently, any JEDEC-compliant 5V, 44-pin wide-body SOIC (a.k.a. SOP) parallel flash IC or mask ROM will do. These are almost always 2 MiB or less, when you can find them (Digi-Key does currently stock the SOIC 29F800).
wbc wrote:so does IWSBOS (or modified versions) work without original rom or it is still required for something? (lazy to read previous posts, sorry 😵 )
The officially-released versions of IWSBOS support two modes of operation; RAM and ROM. In ROM mode, an on-board ROM is required (as expected). The ROM must then contain a somewhat-valid SBOS chunk, or IWSBOS will abort. In RAM mode, the presence of the ROM is ignored, and a set of IWL files is used instead. These files can be generated from any FFF/DAT bank, but the data will be re-sampled so that it fits within files of a certain size. You will typically end up with inferior sound quality, compared to a complete ROM with SBOS chunk (that may not always be the case, but our testing up to this point supports that claim).