I've built a homebrew ATA controller for my II systems - according to my research, it should boot (the appropriate version of) ProDOS perfectly on just about any II within reason. My GS-3 boots every version of ProDOS I throw on it, impressively fast considering how simple the design is. Trouble is, GS/OS won't boot.
Now, currently the conditions are:
1. I haven't finalized the ROM code yet, to make it non-slot-dependent - currently it only works in slot 7.
2. I've written a generic ProDOS block driver for it, which simply maps 65535 blocks to the lowest 16 bits of LBA sectors.
3. Partitioning hasn't yet been under consideration.
4. GS/OS booting from 3.5 floppy can see the darned thing!
5. Recently the last rev of the ROM was written to support second drive, and to save/set/restore the emulation bit upon calling the block driver.
Currently my concerns are:
1. Partitioning - is it necessary?
2. Will GS/OS refuse to talk to me until I have a SmartPort ROM implemented?
3. A boot driver? Is there one for a generic block device? Will I have to write one? :o
4. Are ScsiHD.driver and SCSI.Manager working against me?
5. Is my problem caused by something stupid, like it won't boot from slot 7, or stupid stuff like that?
6. Am I still too much of a n00b on the 65C816, like is there more I have to do than set the emulation bit (like changing bank regs or something)?
Now I'm a really old hand with the II systems, but never having a GS until recently, I'm new to GS/OS, and having only a 3.5 to boot from is a bummer - hence this project. Problem is, knowing so little about GS/OS is convincing me that I don't know enough to answer my own questions. I may have to boot trace through the stinking thing or tear apart the boot block to see if I can figure out what's wrong.
Anyone have any ideas? Or perhaps want to lend a hand? Just for a credit though - I plan to publish this project in full to the general public when it's done, not to make money. Zero budget nerd wants to help other zero budget nerds, etc. - anyone who knows how to solder and has a small supply of parts and a TTL book or two ought to be able to duplicate my design easily. Even now it should be totally suitable to give to the II*,II+,//e crowd, but goshdarnit I want the thing to be complete before I do that.
* yes - I know, as long as the II in question has had its ROMS replaced with Applesoft ROMS and has a language card.