RC2016/10 is a little more than halfway over... so where am I?
Pretty much in the weeds.
I'm almost at the point where I wanted to be at the beginning of the challenge. I'm still working on finishing up the SD loader routines. Well, I've finished the SD/Micro side of things (in the SSDD1 module - Serial SD Drive) both for the real physical drive as well as for the emulator, for loading only. The emulation also supports writes now, and both support file/directory manipuations: Directory listings, make directory, remove directory/file. (For the FAT filesystem anyway.)
I've got a bunch of things on my plate right now, between work, finishing up a contract or two, the animatronic bird project has reappeared a bit, plus time for the family, lack of sleep, and general lack of motivation for anything.
I haven't done any of the sector IO stuff yet, as I want to get regular files working.
In any event, here's a quick bullet summary of the current state of the project:
- Hardware for SD interface
- Hardware for ROM/RAM switcher
- SSDD1 process design (see image above)
- SD drive (SSDD1) firmware (preliminary)
- SSDD1 emulation for file and directory support
- SSDD1 firmware for directory support and file reading
- CP/M research to figue out what needs to be done, prior work.
- SSDD1 firmware for file writing
- SSDD1 firmware and emulation for simulated sector IO
- Z80 SSDD1 decoder (Hex string+checksum to proper formatter)
- Z80 IHX decoder (stream from SSDD1 to RAM writer
Gameplan tasks (Roughly in order of probable completion):
- Z80 IHX decoder
- Load a ROM from the SD card into RAM, switch off the boot ROM, restart, run from RAM
- Backport emulation into the firmware to get them equal
From here, I can go down one of two paths. I can completely flesh out the rest of the SSDD1, and get the sector IO code implemented, which is probably the best course of action, just for completeness. Or I could start working on porting/implementing the CP/M bios ROM, which might give me the "win" kick that I need to get the Sector interface implemented... although once I have the regular file IO stuff done (which it is) the sector IO stuff is the same plus a bit more wrapper implementation... after all it's just a bunch of 128 byte files in subdirectories... so...
- Sector IO SSDD1 emulation
- Backport Sector IO to SSDD1 firmware
- CP/M Bios
- CP/M Bootloader into LLoader ROM
- Burn new LLoader ROM to 27C512 EPROM
- Boot a RC2014 to CP/M!