Well this project has really developed over the past month or so. I teamed up with Jeff Mazur (an Apple ][ programming guru), slung a CPLD on the underside and ended up with the following features:
1. Same low profile, small footprint as the first board!
2. No switches! System boots a menu screen from the ROM at first powerup - all ROM selections are done from the keyboard!
3. 16 ROM images including the master boot image!
4. All 16 ROM images including the master boot image are user programmable
in system!
5. ROM-LINK interface to a text ROM board - with text ROM selection through the same menu!
6. You can set a default ROM image for both system and text ROM - system menu will time out and boot your default!
7. Info (128 bytes) can be stored for each ROM image!
8. We've registered the domain theromexchange.com - will be used to share ROM images!
The 2316B SPCL Text ROM replacement (connects to the main ROMX board via ROM-LINK interface, so you can use the menu to select text ROMS):
There is another version of the text ROM board for pre rev 7 mainboards which upgrades the text capability on the pre rev 7 to that of the rev 7.
Proof of concept running in my ][ europlus:
Undergoing timing analysis/debug during development:
PCB's shown in the Altium renders above are with DHL and I'm hoping to receive them this week! I'll be changing the JTAG header for a TAG-Connect one on the production boards, but hopefully this is it - quite possibly the ultimate ROM setup for an Apple ][/][+...