jake/SplitBit-Emulator
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Give the screen back: osTakeScreen, and the RAM disk earns its keep

Browse Source 
A program that takes the whole screen leaves the shell a blank one, and
whatever was on it is gone. There was nowhere to put 48K of video memory on
a machine with 64K of Data Memory that CosmOS already lives in.

A DRIVE MADE OF MEMORY IS SOMEWHERE. The screen goes to a file on the
scratch drive - the first volatile drive found at boot - like any other
file, and comes back from handleExit alongside the vectors and console mode
already put back there. The filesystem does the allocating, so this
invented nothing: it is 196 pages of tiles, map and palette, with a block
on the front holding the cursor, the four scroll registers and the mode.

NOT AUTOMATIC, and that is the whole design. Saving on every program start
would be cheap enough; restoring on every exit would be wrong, because dir
and Files and Say print and stop and their output is the reason you ran
them. A program says it took the screen, and one that says nothing behaves
exactly as every program did before this existed.

It deleted thirty lines of Grid, and they were all wrong anyway: four
scroll registers put back by hand, the map filled with spaces, the cursor
sent home, palette bank 0 written out - and the other fifteen banks kept
Grid's colours, because there was nowhere to have kept the real ones. Grid
is 64 bytes smaller and gives back what was actually there.

The check compares the screen before against the screen after, CELL BY
CELL, and allows only the rows around the cursor to differ - found from
where the text ends rather than guessed at, because the first version
assumed the cursor was near the bottom of the screen and let three real
differences through.

Two things cost time and neither was the feature:

  - An edit adding "SWI osTakeScreen" to Grid was in the same script as a
    failing s.index, so the file was never written - and the COMMENT
    describing the call did land, from a later edit. Grid documented a call
    it did not make, and read as though it should have worked.
  - docs.sh caught osTakeScreen having no row in the services table, which
    is the check the service layer added for exactly this and the second
    time it has earned itself.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
This commit is contained in:
Anachronaut
2026-08-31 18:47:44 -04:00
co-authored by Claude Opus 5
parent 04f1ffabd4
commit ab72443b99
12 changed files with 551 additions and 71 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Programs/CosmOS/Apps/Grid.asm
+14 -65
View File
@@ -44,6 +44,14 @@ start:
INIA 0x03
OUTA 0xE8 ; RegisterBank.
; ---- Asking for the screen back afterwards ----
;
; Everything below overwrites a tile, all sixteen colour schemes and every cell of the map,
; and none of that is this program's to keep. The system puts it somewhere and gives it back
; at exit - and if it says it cannot, this carries on anyway, because it did before there
; was anywhere to put it.
SWI osTakeScreen
CALL putTile
CALL putPalette
CALL putMap
@@ -119,74 +127,15 @@ finished:
; ---- Putting the screen back ----
;
; All four scroll registers, or the shell inherits a view that begins half way into a cell.
RSTA
OUTA 0x36
OUTA 0x37
OUTA 0x38
; The row origin too, and then every cell of the map and not just the visible ones. A
; console that scrolls would otherwise walk down into rows this program filled, and find a
; grid underneath its own output.
OUTA 0x34 ; A is still nought, from the three above.
INIA 0d4
OUTA 0xE3
INIA 0x40
OUTA 0xE4
RSTA
OUTA 0xE5
OUTA 0xE2 ; The byte to write: tile 0 is the space, attribute 0 is plain.
INIA 0x80
OUTA 0xE6
RSTA
OUTA 0xE7 ; 0x8000 bytes, which is the whole map.
INIA 0x02
OUTA 0xE8 ; Fill.
; ---- And the cursor back to the top ----
; ---- What used to be here ----
;
; The Fill above empties the map and says nothing to the console about it, so the shell
; carried on writing from wherever the cursor had been left standing when this program
; started - part way down a screen that no longer has anything on it. Clearing is what
; puts a cursor home, and it costs one write.
INIA 0x01
OUTA 0x05
; ---- And the colours it woke up with ----
; Four scroll registers put back, the whole map filled with spaces, the cursor sent home,
; and palette bank 0 written out by hand - and it was STILL wrong, because the other fifteen
; banks kept this program's colours and there was nowhere to have put the real ones.
;
; Only the first pair, and that is worth being honest about. The console's own scheme is
; sixteen banks - colours on black in 0 to 7, the same colours inverted in 8 to 15 - and
; this program wrote over all of them, because the attribute nibble lands on exactly the
; entries the console uses and there is nowhere else for it to land. Putting all thirty two
; back would mean copying the device's own table into an application, which is the kind of
; duplication that goes stale the first time somebody picks a nicer green.
;
; So it restores bank 0, grey on black, which is what plain text has always been and what
; the shell will be using when it gets the machine back. The other fifteen keep this
; program's colours until something else writes them, which is visible only to a program
; that sets the console's attribute port.
;
; THE REAL ANSWER IS A COMMAND TO THE SCREEN saying "give me back what you woke up with",
; the same way the console has one for clearing. There is not one, and this program is the
; first thing that ever wanted it.
INIA 0d4
OUTA 0xE3
INIA 0xFC
OUTA 0xE4
; All of it is osTakeScreen's now, and it gives back what was actually there rather than
; what a clean machine looks like.
RSTA
OUTA 0xE5
OUTA 0xE9 ; Entry 0, the paper: black.
OUTA 0xE9
OUTA 0xE9
OUTA 0xE9
INIA 0xD8
OUTA 0xE9 ; Entry 1, the ink: grey.
OUTA 0xE9
OUTA 0xE9
RSTA
OUTA 0xE9
OUTA 0x02 ; Line mode, the way it was found.
RSTA ; splitlint[redundant-assignment]: an exit status, not a mode
SWI osExit
Programs/CosmOS/README.md
+31
View File
@@ -870,6 +870,36 @@ too, and that is no use on a disk which has not got one. The directory is sixtee
names, chosen rather than worked out: a scratch disk runs out of names long before it runs out
of room, and this machine cannot divide.
### Giving The Screen Back:
A program that takes the whole screen leaves the shell a blank one, and whatever was on it -
the listing you were reading, the error you were about to act on - is gone. There is nowhere
to put 48K of video memory on a machine with 64K of Data Memory that CosmOS is already living
in.
**A drive made of memory is somewhere.** `SWI osTakeScreen` says *"I am about to use the whole
screen, and would like what is on it now put back when I exit."* The system writes video
memory to a file on the scratch drive and restores it from `handleExit`, alongside the vectors
and console mode it already puts back. Q is zero if that was arranged; a machine with no
volatile drive says no, and **a program told no should carry on regardless**, because it was
going to before this existed.
**It is not automatic, and that is the point.** Saving on every program start would be cheap
enough, but restoring on every exit would be wrong: `dir`, `Files` and `Say` print and stop,
and their output is the reason you ran them. A program that says nothing behaves exactly as
every program did before this existed.
**Tiles, map and palette all go** - 196 pages, and a block on the front holding the cursor,
the four scroll registers and the mode. The map's off-screen rows are the console's
scrollback; the tiles are the font, which a program that redefines one has overwritten; and
the palette is where the console's own colours live. `Grid` used to give back the map and not
the colours, and handed the shell green text on a blue ground.
It also replaced thirty lines of `Grid`: four scroll registers put back by hand, the map
filled with spaces, the cursor sent home, and palette bank 0 written out - all of which was
*still* wrong, because the other fifteen banks kept `Grid`'s colours and there was nowhere to
have kept the real ones.
### Where A Program Is Looked For:
Three places, tried in order:
@@ -939,6 +969,7 @@ Those numbers are written down once, in `Programs/CosmOS/Source/services.asm`, w
| osPrintNumber | A and B together are a number. Prints it in decimal, without leading zeroes. |
| osBreak | Stops the program, shows every register as it had them, waits for a key, and carries on. |
| osLastStatus | Q answers what the last program exited with: 0 it did what it was asked, 1 it did not, 2 it was asked wrongly. A program may give its own meanings if it says so. |
| osTakeScreen | Says this program is about to use the whole screen and would like what is on it put back when it exits. Q is zero if that was arranged; anything else means it was not, which is the ordinary answer on a machine with no volatile drive. See Giving The Screen Back. |
| osBootState | Q answers how the last start went: 0 settled, 1 trying, 2 fell back. A machine with no disk answers settled, because there is nothing there to be unsettled about. |
| osBootSettle | Puts it back to settled, which is how a machine that fell back is told the situation has changed. Q is zero if the disk took it. **Settling is the only write a program gets** - marking a start as trying or fallen back is the loader's business, and a service that let a program claim either would let it lie about something the loader cannot check. |
Programs/CosmOS/Source/cosmos.asm
+393
View File
@@ -1840,6 +1840,373 @@ scriptNoName:
;
; SET WHEREVER A PROGRAM STARTS, of which there are two: run, and typing a program's name.
; Restored in handleExit, which is the one place they both come back through.
; ---- Putting the screen somewhere and getting it back ----
;
; A program that takes the whole screen leaves the shell a blank one, and everything that was
; on it - the listing you were reading, the error you were about to act on - is gone. There is
; nowhere to put 32K on a machine with 64K of Data Memory that CosmOS is already living in.
;
; A DRIVE MADE OF MEMORY IS SOMEWHERE. The map goes to a file on the scratch drive like any
; other file, and comes back the same way; the filesystem does the allocating, and this had to
; invent nothing at all to have somewhere to put it.
;
; EVERYTHING A PROGRAM CAN DISTURB, which is more than the part on screen. The map's off
; screen rows are the console's scrollback; the tiles are the font, which a program that
; redefines one has overwritten; and the palette is where the console's own colours live -
; Grid could give back the map and not the colours, and handed the shell green text on blue.
;
; 192 pages of tiles and map, which are next to each other, then the four of palette. 196 in
; all, and a register block on the front.
;
; ---- Saved on being asked, restored on the way out ----
;
; Saving on every program start would be cheap enough. Restoring on every exit would be
; WRONG: dir, Files and Say print and stop, and their output is the reason you ran them.
; So a program says it is taking the screen, and one that says nothing behaves exactly as
; every program did before this existed.
screenTake:
SETD.0 SbfsScratch1
LDA.0
INIB 0xFF
CCF
SUB
BRQ screenNoScratch ; No volatile drive, so nowhere to put it.
; Where the caller was, and where the file is going.
INA 0x24
SETD.0 ScreenWasDrive
STA.0
SETD.0 SbfsScratch1
LDA.0
CALL sbfsUse
CALL screenBank
; A hundred and twenty nine blocks: one of registers, then the map.
SETD.0 SbfsFileBlocks
RSTA
STA.0
INCD.0
INIA 0d197
STA.0
SETD.0 SbfsFileTail
RSTA
STA.0
SETD.0 ScreenFileName
CALL sbfsStreamStart
BNQ screenTakeFailed
; Block nought is where the screen was, rather than what was on it: the cursor, the four
; scroll registers and the mode. A picture put back under a different origin is not the
; picture that was taken.
CALL screenClearBlock
SETD.0 ScreenBlock
INA 0x03
STA.0
INCD.0
INA 0x04
STA.0
INCD.0
INA 0x34
STA.0
INCD.0
INA 0x36
STA.0
INCD.0
INA 0x37
STA.0
INCD.0
INA 0x38
STA.0
INCD.0
INA 0x31
STA.0
RSTA
RSTB
SETD.2 SbfsIndex
STA.2
INCD.2
STB.2
SETD.1 ScreenBlock
CALL sbfsStreamWrite
BNQ screenTakeFailed
; And the map, a block at a time through the one buffer there is.
RSTA
SETD.0 ScreenAt
STA.0
screenTakeBlock:
SETD.0 ScreenAt
LDA.0
CALL screenPageFor
MVQA
CALL screenFromVideo
SETD.0 ScreenAt
LDA.0
INCA
SETD.2 SbfsIndex
RSTB
STB.2
INCD.2
STA.2 ; Block n of the map is block n+1 of the file.
SETD.1 ScreenBlock
CALL sbfsStreamWrite
BNQ screenTakeFailed
SETD.0 ScreenAt
LDA.0
INCA
STA.0
INIB 0d196
CCF
SUB
BNQ screenTakeBlock
SETD.0 SbfsFileBlocks
RSTA
STA.0
INCD.0
INIA 0d197
STA.0
SETD.0 SbfsFileTail
RSTA
STA.0
CALL sbfsStreamDone
BNQ screenTakeFailed
INIA 0x01
SETD.0 ScreenSaved
STA.0
CALL screenGoBack
RSTA
RSTB
CCF
ADD
RET
screenTakeFailed:
RSTA
SETD.0 ScreenSaved
STA.0
CALL screenGoBack
screenNoScratch:
RSTA
INIB 0d1
CCF
ADD
RET
; Whatever screenTake put away, put back. Nothing at all if it never ran.
screenGive:
SETD.0 ScreenSaved
LDA.0
BRA screenGiveNone
RSTA
STA.0 ; Once only: the next program takes its own.
INA 0x24
SETD.0 ScreenWasDrive
STA.0
SETD.0 SbfsScratch1
LDA.0
CALL sbfsUse
CALL screenBank
SETD.0 ScreenFileName
CALL fileLookup
BNQ screenGiveDone
; The map first, then the registers, so that nothing is drawn under an origin that is about
; to change.
RSTA
SETD.0 ScreenAt
STA.0
screenGiveBlock:
SETD.0 ScreenAt
LDA.0
INCA
SETD.2 SbfsIndex
RSTB
STB.2
INCD.2
STA.2
SETD.1 ScreenBlock
CALL sbfsReadOne
BNQ screenGiveDone
SETD.0 ScreenAt
LDA.0
CALL screenPageFor
MVQA
CALL screenToVideo
SETD.0 ScreenAt
LDA.0
INCA
STA.0
INIB 0d196
CCF
SUB
BNQ screenGiveBlock
; And where it was.
RSTA
RSTB
SETD.2 SbfsIndex
STA.2
INCD.2
STB.2
SETD.1 ScreenBlock
CALL sbfsReadOne
BNQ screenGiveDone
SETD.0 ScreenBlock
LDA.0
OUTA 0x03
INCD.0
LDA.0
OUTA 0x04
INCD.0
LDA.0
OUTA 0x34
INCD.0
LDA.0
OUTA 0x36
INCD.0
LDA.0
OUTA 0x37
INCD.0
LDA.0
OUTA 0x38
INCD.0
LDA.0
OUTA 0x31
screenGiveDone:
CALL screenGoBack
screenGiveNone:
RET
; Video memory as bank 4, which is what makes it reachable at all. Bank 3 is the disk's; see
; the table in the CosmOS README, which exists because a program once took 3.
screenBank:
INIA 0d4
OUTA 0xE3
INIA 0x30
OUTA 0xE2
INIA 0x03
OUTA 0xE8
RET
; Back to the drive whoever called was standing on.
screenGoBack:
SETD.0 ScreenWasDrive
LDA.0
CALL sbfsUse
RET
; ---- Which page of video memory a saved block is ----
;
; Nought to 191 are the tiles and the map, which sit next to each other from 0x0000. After
; that comes 16K of nothing, so 192 to 195 jump to 0xFC and are the palette. One sum rather
; than two loops, because two loops is two places to get the file's block numbers wrong.
screenPageFor:
INIB 0d192
CCF
SUB
BRC screenPageDirect ; Borrowed, so it is below 192 and the page is the index.
MVQA
INIB 0xFC
CCF
ADD
RET
screenPageDirect:
RSTB
CCF
ADD
RET
; A holds a page of video memory. Its 256 bytes come into ScreenBlock.
screenFromVideo:
PSHA
INIA 0d4
OUTA 0xE0
POPA
OUTA 0xE1
RSTA
OUTA 0xE2
INIA 0x01
OUTA 0xE3 ; Into Data Memory.
CALL screenBufferDest
CALL screenLength
INIA 0x01
OUTA 0xE8
RET
; A holds a page of video memory. ScreenBlock goes back into it.
screenToVideo:
PSHA
INIA 0d4
OUTA 0xE3
POPA
OUTA 0xE4
RSTA
OUTA 0xE5
INIA 0x01
OUTA 0xE0 ; Out of Data Memory.
CALL screenBufferSource
CALL screenLength
INIA 0x01
OUTA 0xE8
RET
; Where ScreenBlock is, told to the controller. A Data Pointer's two bytes cannot be read out
; of it, so it goes to memory first and comes back a byte at a time.
screenBufferDest:
SETD.1 ScreenBlockAt
SETD.0 ScreenBlock
STD.0.1
LDA.1
OUTA 0xE4
INCD.1
LDA.1
OUTA 0xE5
RET
screenBufferSource:
SETD.1 ScreenBlockAt
SETD.0 ScreenBlock
STD.0.1
LDA.1
OUTA 0xE1
INCD.1
LDA.1
OUTA 0xE2
RET
screenLength:
INIA 0x01
OUTA 0xE6
RSTA
OUTA 0xE7 ; 0x0100, which is one block.
RET
; The block, emptied. Everything the register block below does not fill has to be nought, or
; a screen restored would carry whatever the last file read left in here.
screenClearBlock:
SETD.0 ScreenBlock
RSTB
screenClearByte:
RSTA
STA.0
INCD.0
DECB
BNB screenClearByte
RET
; ---- run ----
;
; Hands the machine to whatever was loaded. Where the Stack is now is written down first,
@@ -2683,6 +3050,16 @@ bootSettleNo:
ADD ; A is the answer, so Q becomes it.
SRET
; The program is about to draw over everything. Q says whether what is there now will come
; back, and a program that is told no carries on anyway.
handleTakeScreen:
CALL screenTake
MVQA
MVSD.2
DPUP.2 0d02
STA.2
RETI
handleExit:
; ---- What the program made of it ----
;
@@ -2695,6 +3072,9 @@ handleExit:
SETD.1 LastStatus
STA.1
; What was on the screen before this program had it, if it asked for that.
CALL screenGive
; The drive the person was on, whatever the program did with it.
PSHA
SETD.1 RunDrive
@@ -3909,6 +4289,8 @@ Separator:
; Where a program is looked for when it is not where you are. One fixed place rather than a
; list somebody sets, because a list would need somewhere to live between one boot and the
; next, and there is no such place yet.
ScreenFileName:
"sbfs.screen"
AppsPrefix:
"/Apps/"
SystemAppsPrefix:
@@ -4194,6 +4576,16 @@ SearchDrive:
0x00
RunDrive:
0x00
ScreenSaved:
0x00
ScreenWasDrive:
0x00
ScreenAt:
0x00
ScreenBlockAt:
0x00 0x00
ScreenBlock:
#Reserve 0d256
FileCacheValid:
0x00
FileCacheName:
@@ -4391,6 +4783,7 @@ CommandLine:
osPrintNumber handlePrintNumber
osBreak handleBreak
osLastStatus handleLastStatus
osTakeScreen handleTakeScreen
osBootState handleBootState
osBootSettle handleBootSettle
Device 0x20 diskDone
Programs/CosmOS/Source/sbfs.asm
+27
View File
@@ -284,6 +284,9 @@ sbfsMountAll:
SETD.1 SbfsDrive
STA.1
OUTA 0x24 ; Drive 0, whatever the controller was left on.
INIA 0xFF
SETD.1 SbfsScratch1
STA.1 ; No scratch drive until one is found.
; The live record belongs to nobody yet, so every slot starts empty and a drive that fails
; to mount keeps an empty one.
@@ -347,6 +350,26 @@ sbfsMountEach:
BNQ sbfsMountNext
sbfsMountGot:
; ---- And whether this is the one to keep scratch on ----
;
; A volatile drive is somewhere the system may write without asking, because nothing on it
; outlives the machine. The FIRST one found is the scratch drive; a machine with two has
; made a decision nobody expressed, and taking the lower number is at least predictable.
INA 0x26
INIB 0x01
AND
BRQ sbfsMountNotScratch
SETD.1 SbfsScratch1
LDA.1
INIB 0xFF
CCF
SUB
BNQ sbfsMountNotScratch ; There is one already.
SETD.1 SbfsDriveAt
LDA.1
SETD.1 SbfsScratch1
STA.1
sbfsMountNotScratch:
; Mounted: remember which, and put the live record where it belongs.
SETD.1 SbfsDriveAt
@@ -3661,6 +3684,10 @@ SbfsDriveCount:
0x00
SbfsDriveAt:
0x00
; Which drive the system may write scratch to, or 0xFF for a machine with none. It is a drive
; the machine called volatile, so nothing written there was ever going to survive anyway.
SbfsScratch1:
0xFF
SbfsPathWanted:
0x00
Programs/CosmOS/Source/services.asm
+11
View File
@@ -167,3 +167,14 @@
; print it: a program that failed has already said so in words, and a number beside that
; would be noise. This is for the thing that cannot read words.
osLastStatus 0d35
; ---- Taking the screen, and giving it back ----
;
; Says that this program is about to use the whole screen and would like what is on it now put
; back when it exits. Q is zero if that was arranged; anything else means it was not, which is
; the ordinary answer on a machine with no volatile drive to keep it on - and a program told
; no should carry on regardless, because it was going to before this existed.
;
; NOT AUTOMATIC, and that is the point: dir and Say print and stop, and their output is the
; reason you ran them. Only a program that says it took the screen gets the screen put back.
osTakeScreen 0d36
Tests/expected/cosmosCrossDisk.out
+1 -1
View File
@@ -12,7 +12,7 @@ Snake.sbx 2164
Keys.sbx 664
Say.sbx 156
Break.sbx 149
Grid.sbx 543
Grid.sbx 479
notes.txt 21
Apps <dir>
hi.script 121
Tests/expected/cosmosDrives.out
+1 -1
View File
@@ -7,7 +7,7 @@ Snake.sbx 2164
Keys.sbx 664
Say.sbx 156
Break.sbx 149
Grid.sbx 543
Grid.sbx 479
notes.txt 21
Apps <dir>
hi.script 121
Tests/expected/cosmosGrid.out
+2 -2
View File
@@ -1,7 +1,7 @@
CosmOS
> it says: before Grid
finished
> finished
> finished
> > it says: after Grid
finished
> greet.sbx 211
@@ -11,7 +11,7 @@ Snake.sbx 2164
Keys.sbx 664
Say.sbx 156
Break.sbx 149
Grid.sbx 543
Grid.sbx 479
notes.txt 21
Apps <dir>
hi.script 121
Tests/expected/cosmosRun.out
+1 -1
View File
@@ -7,7 +7,7 @@ Snake.sbx 2164
Keys.sbx 664
Say.sbx 156
Break.sbx 149
Grid.sbx 543
Grid.sbx 479
notes.txt 21
Apps <dir>
hi.script 121
Tests/expected/cosmosSlowDisk.out
+1 -1
View File
@@ -6,7 +6,7 @@ Snake.sbx 2164
Keys.sbx 664
Say.sbx 156
Break.sbx 149
Grid.sbx 543
Grid.sbx 479
notes.txt 21
Apps <dir>
hi.script 121
Tests/samescreen.py
+47
View File
@@ -0,0 +1,47 @@
# Two screens, compared a cell at a time: is the second the first, restored?
#
# Cells rather than pixels, and "ink or no ink" rather than colour, because what is being
# checked is that the TEXT came back - a restore that got the map right and the palette wrong
# would still be a restore that lost the colours, and that is checked by the colours being
# the console's own elsewhere.
#
# THE ROWS AROUND THE CURSOR ARE ALLOWED TO DIFFER, and they are found rather than guessed at.
# The screen is given back and THEN the shell carries on writing to it - a "finished" and a
# prompt, two or three lines - so the bottom of what was there is where they land. The cursor
# is not near the bottom of the SCREEN, so "the last few rows of the screen" is the wrong
# exemption and let a real difference through the first time this ran.
#
# Everything above that is what the restore is judged on, which here is 25 rows of 28.
import sys
def cells(path):
data = open(path, "rb").read()
fields = data.split(b"\n", 3)
width, height = (int(n) for n in fields[1].split())
body = fields[3]
out = []
for cy in range(height // 8):
row = ""
for cx in range(width // 8):
inked = any(
body[((cy * 8 + j) * width + cx * 8 + i) * 3:
((cy * 8 + j) * width + cx * 8 + i) * 3 + 3] != b"\x00\x00\x00"
for j in range(8) for i in range(8))
row += "#" if inked else "."
out.append(row)
return out
before, after = cells(sys.argv[1]), cells(sys.argv[2])
if len(before) != len(after):
print("the screens are different sizes")
sys.exit(0)
differ = [n for n, (b, a) in enumerate(zip(before, after)) if b != a]
inked = [n for n, row in enumerate(before) if "#" in row]
settled = (max(inked) - 3) if inked else 0
early = [n for n in differ if n < settled]
if early:
print("row %d is not what it was" % early[0])
else:
print("yes")
Tests/video.sh
+22
View File
@@ -838,6 +838,28 @@ else
result no "a program drew a grid of its own tile" "no picture came out"
fi
# ---- A program gives the screen back ----
#
# Grid takes the whole screen: it redefines a tile, writes all sixteen colour schemes over the
# console's own, and fills every cell of the map. Then it asks the system for what was there
# before, and the system has somewhere to put it because the machine has a drive made of
# memory.
#
# WHAT IS COMPARED IS THE SCREEN BEFORE AGAINST THE SCREEN AFTER, cell by cell. Checking that
# it merely looks like text would pass on a restore that put back somebody else's text, and
# checking a few pixels would pass on one that got the palette right and the map wrong.
python3 -c "open('$BUILD/before.keys','wb').write(b'dir\n' + b'Say a line to come back to\n' + b'\x00'*200)"
python3 -c "open('$BUILD/after.keys','wb').write(b'dir\n' + b'Say a line to come back to\n' + b'Grid\n' + b'\x00'*600 + b'q' + b'\x00'*200)"
for phase in before after; do
timeout 30 "$EMU" --fast --cycles 200000000 --keyboard "$BUILD/$phase.keys" \
--screen "$BUILD/$phase.ppm" --disk "$ROOT/Tests/build/disks/cosmos.img" \
--ram-disk 2048 "$BUILD/cosmos.bin" > "$BUILD/$phase.out" 2>&1 || true
done
SAME="$(python3 "$ROOT/Tests/samescreen.py" "$BUILD/before.ppm" "$BUILD/after.ppm")"
[ "$SAME" = "yes" ] \
&& result ok "a program gives the screen back" "every row it did not write on is as it was" \
|| result no "a program gives the screen back" "$SAME"
# ---- Clearing puts the cursor back at the top ----
#
# A screen with nothing on it and a cursor half way down it is not a cleared screen. This