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   UltrascreenNEC (NEC PC-8201A / PC-8300) release history
==============================================================================

UltrascreenNEC gives the NEC PC-8201A and PC-8300 a 60-column by 10-line
small-font display where the ROM natively does 40 by 8. It is a port of
Daniel Born's Ultrascreen100. Many thanks to Daniel Born and Richard Eckerlin
for making this a reality.

Editions (from 1.4 on):
  Full       the complete build, with a full-screen BASIC editor. Roughly
             4.8K resident.
  Lite       (L) drops the full-screen editor for a simple Model-100-style
             line editor. Roughly 2.9K resident.
  Lite Fast  (X, formerly LT) Lite line input plus the char-skip TEXT shadow,
             so TEXT keeps up like the Full edition. Roughly 3.8K resident.


1.7  (2026)  Full, Lite (1.7L), Lite Fast (1.7X)
  Safe PC-8300 detection. The 1.6 releases always wrote to the ROM-bank select
  port (163) at install to bring in the 8201A-compatible image, on the belief
  that the write was a harmless no-op on a real PC-8201A. On actual 8201A
  hardware it is not: that write hangs the machine. UltrascreenNEC now reads a
  ROM signature first and only switches banks when it is genuinely running on a
  PC-8300, so the PC-8201A is never touched. Both machines are hardware
  confirmed. The guard costs eight bytes, so the load addresses moved down by
  eight across all three editions (Full 57350, Lite 59443, Lite Fast 58523).


1.6  (2026)  Full, Lite (1.6L), Lite Fast (1.6X)
  Automatic PC-8300 support. UltrascreenNEC now runs on the NEC PC-8300 as well
  as the PC-8201A, with nothing to switch by hand. At install it selects the
  8201A-compatible ROM image, which was believed to be a harmless no-op on a
  real 8201A, so a single build serves both machines. (See 1.7: that write was
  in fact not harmless on the 8201A, and 1.7 gates it behind a hardware check.)

  Smaller footprint. The scroll scratch buffers moved into a ROM line buffer
  that sits idle while Ultrascreen is showing 60 columns, trimming about 100
  bytes off both the code and the resident size across all three editions.


1.5  (2026)  Full
  Snappier full-screen BASIC editor. Backspacing and deleting used to repaint
  more of the line than they strictly needed to. The editor now recognizes
  when there is nothing to pull in behind the cursor and skips the extra work,
  and it keeps the fast screen-shadow trick going during ordinary cursor
  editing, so editing feels noticeably lighter.


1.4X  (2026)  Lite Fast
  Same build as 1.4LT, re-badged 1.4X. Only the banner version string changed;
  no functional difference.


1.4  (2026)  Full, Lite (1.4L), Lite Fast (1.4LT)
  Faster TEXT. The small font used to redraw a lot of pixels on every
  keystroke, so this release keeps a shadow copy of the screen and repaints
  only the cells that actually change. Also uses the NEC's native TEXT
  end-of-line and end-of-file glyphs, and moves the screen shadow out of the
  shipped .CO so the file on disk is smaller.

  Introduced the edition split: Lite (1.4L, line-input only) and Lite Fast
  (1.4LT, Lite line input plus the char-skip TEXT shadow) join the Full build.


1.3  (2026)  Full, Lite (1.3L)
  First stable UltrascreenNEC. Full 60x10 driver with a full-screen BASIC
  editor, SCREEN 0 / SCREEN 1 to toggle 40 and 60 columns, and CLEAR-based
  uninstall. 1.3L is the Lite companion: the same 60x10 display with a simple
  line editor and no screen shadow.


1.2  (2026)  Full
  Short-lived first release. Withdrawn as unstable and superseded by 1.3.
