The shell printed "finished" every time a program gave the machine back.
That made sense when starting a program and getting the machine back was
most of what the machine did and the prompt was the only other thing on
the screen. Under a listing, between two commands, it is noise.
And it was printed whatever the program made of it, so a program that had
just explained what went wrong was answered with the word "finished" -
"there is no such directory: nowhere" and then, immediately, "finished".
The prompt coming back is what says a program is over. It is the same
argument osLastStatus is made of: a program that failed has already said
so in words, and anything the shell adds beside that is the shell talking
over it. A program that FAULTED still says so, because the fault screen
printed in red above and a program that is gone should not look like one
that ended.
A NEWLINE ONLY IF ONE IS WANTED. A program that stopped part way along a
line would leave the prompt sitting in the middle of its last output,
which the word used to prevent by accident. The console knows which
column the cursor is in, so the shell asks - where a blank line printed
every time would be right about half of the time, and an empty directory
listed with ls would be followed by a blank line for no reason.
Fifty nine recorded sessions lose the word. Two of them move a cursor up
a row with it, which is the same fact seen from the screen.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
CosmOS had 1,161 bytes of Program Memory left before the address applications
load at, and Tab completion is not going to fit in that with anything to spare.
So the wall moves up one page: the system keeps below 0x4FFF and 0x2FFF, and an
application is based at 0x5000 and 0x3000.
A PAGE IS A CHEAP THING TO GIVE IT AND AN EXPENSIVE THING TO RUN OUT OF. An
application still has 44K of Program Memory before the vector table and the
largest one here uses 7.5K, so what was taken from applications is space nothing
has ever asked for - while what the system gained is the difference between
building the next thing and counting bytes while building it.
Not doubling, which was the version that would have cost application space worth
minding. One page, and the same again when it is needed.
Nothing in the machine knows where the wall is, so this is 34 #Base lines, one
threshold in the fault handler, and the table in the CosmOS README that
Tests/docs.sh reads its limits out of.
The native assembler's scratch map had to move with it, and docs.sh said so
before anything ran: its data reached 0x40D6 and its buffers began at 0x4000, so
they were sitting on its variables. That file already carries a paragraph about
the floor coming up and the map staying where it was. It has happened twice now,
and been caught by a check the first time wrote.
Twenty three recordings are the same runs a page higher.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
osReadLine goes through the shell's editor now, so anything that asks the system
for a line gets arrows, Home, End and Delete. The editor is a program, and a word
typed with two letters the wrong way round can be put right without starting the
line again.
IT DOES NOT GET THE HISTORY, and that is the interesting half. Edit would
otherwise fill the history with the text of somebody's document, and pressing Up
in the middle of writing one would put "dir" into it. The history belongs to the
thing whose lines are commands. Two entry points rather than a flag the caller
sets first, so a caller cannot forget which it wanted.
And the console is put back the way it was FOUND rather than the way the shell
likes it. A program that had asked for key mode and then read a line through the
system used to be handed back a console in line mode having asked for nothing of
the sort. The status port reports all three things the control port can ask for,
in the same order two bits along, so one shift turns what the console IS into
what to write to make it that again.
Which uncovered a real fault in the console. READING THE STATUS PORT WAS EATING A
KEY: in line mode the poll consumed an arrow key and dropped it, so a program
that looked and then asked for key mode - exactly what reading a line now does -
found the first key it was reaching for already gone. A look must not consume
what it cannot report, because the mode can change. It is held now and delivered
as soon as something will take it. A blocking read still discards it, and must:
that read IS the delivery, and a byte held there would be met again forever.
Four recordings gained a program's echo, and cosmosEdit's went from
"> : : : : > : : > 1: alpha" to a session you can read. VERIFIED THE SAME WAY AS
BEFORE: with only the program side of the echo silenced, all 192 tests pass
against the recordings as they were before this commit, so the echo is the whole
of what changed.
cosmosEditService is the new test and it checks both halves at once. Inside Edit,
Left/Delete/Left puts "alpah" right. Up and Down do nothing there - were a
program's line walking the shell's history, the next line would come out as the
echo command from the top of the file instead of the word. And one press of Up
back at the prompt finds the command typed before Edit was started, which is the
proof that nothing the editor read went into the history at all.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
AnachronautandClaude Opus 5