* interpro: headless boot working
These fixes enable booting and CLIX installation on headless InterServe systems (InterPro systems without graphics) using a VT100 or VT220 compatible terminal on serial port 2 (0 for ip6000). It's now possible to install and boot CLIX on the ip6000 system, as this works around the issues with the incomplete graphics hardware support in the driver.
* interpro: tidy serial configuration, add missing control lines
* ioga: fix serial dma
* z80scc: update /WREQ when transmitter is enabled/disabled, use 0 for assert state of active low output
* softlist: added 60x0 CLIX root floppies
* z80scc: tidy (nw)
Many changes, most notable end result is the ability to boot the "blue screen" rebuild floppy, and nearly booting CLIX (hangs trying to mount the filesystems).
Summary of changes:
* added a softlist
* refactored cpu/mmu memory access
* added alignment faults
* implemented most c400 instructions
* fixed wait instruction
* corrections to interpro driver
* removed broken forced interrupt handling
* added support for dma virtual addressing
