This implements the principle of "least surprise", in that users won't
normally expect to start overwriting an existing file on these devices.
Real hardware didn't behave that way. A new (empty) file can always
be created with the -N switch on the ATTACH.
1. Added RP03 support and supporting "SET" commands.
2. Fixed implementation of DPCF (it's a full reset and not blocked by BUSY).
3. Fixed handling of JOB DONE flag (not touched by NOP, SEEK, or RECAL).
- Added unix v0 terminal support
- Added 3-cycle databreak set/show entries
- Revised for dynamically allocated memory
- Added support for -u modifier (UC15 and Unix v0)
These changes are to support the Unix v0 bringup and to implement a
"Unix input" mode on the console terminal. In Unix mode, CR and LF are
swapped (so that a modern terminal can use 'enter' instead of CTRK-J to
create the newline Unix expects), escape is mapped to altmode (175),
upper and lower case are enabled and the parity bit is forced to 1. This
most closely matches the characteristics of the KSR-37, but there is no
definitive evidence of the terminal that was actually used.
This merges the latest PDP18B changes from Bob Supnik:
- It adds the RB disk to the PDP-7 and the drum (DRM) to the PDP-9, per the
discoveries in the 18b services listing.
- It tweaks the switches for examine and deposit to support Unix v0 and
(eventually) the Unichannel.
