2nd March 2021
ROMXc/ROMXe firmware is progressing well. We hope to show you the current status next weekend, with a few screen captures of the menu system, and ProDOS etc.
In between smashing out code for the new ROMXc and ROMXe boards, Jeffs been looking at Apple II clones/reproductions, and any modifications required for ROMX.
First of these is the ReActiveMicro.com Apple II Plus, Rev 7 RFI Motherboard.
ReActiveMicro.com offers two versions of its Rev 7 RFI Motherboards. One uses 93-series ROMS and is fully compatible with ROMX. You can use this motherboard even if you do not have any of the original ROMs.
The 27-series motherboard is designed to use 27xx type EPROMS and corrects the INH pin polarity by adding a 74LS04 inverter chip in the normally vacant location H11.
Aside from power and ground, only two pins on this chip are used: 8 and 9. To work with ROMX, you need to remove this chip and add a small jumper between these two pins. This could be done using a 14-pin DIP header or component carrier. Or you can just insert a small jumper wire into the two socket pins.
ROMX can then be installed in the F11/F12 positions as per normal and will operate as intended.