Maintenance script: Initial automated import

2016-02-06T06:04:05Z

Initial automated import

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The system flags are a special place in memory pointed to by the IY index register, which points to ''flags''. They contain vital information that can be stored in 1 bit, so they have been compressed into 1 bit to save space. If you ever need to restore the IY register back before quiting, do this:

ld IY,flags

To do something to the flags (set, reset, or bit), do this:

set trigDeg,(IY+trigFlags) ;trigDeg is now 1
res trigDeg,(IY+trigFlags) ;trigDeg is now 0
bit trigDeg,(IY+trigFlags) ;Tests trigDeg

== Assembly Flags ==

If you look at the bottom of the flags table, you'll notice that there are 3 bytes for assembly flags. These are flags that are not used by the OS, and can be used by assembly programmers for their own purposes.

#define shoot asm_Flag1_0
# define weaponFlags asm_Flag1

= System Flags Breakdown =

Here's a breakdown of the system flags:

{| class="wikitable"
! Flag Name !! IY Offset !! Equate Description !! Comments
|-
| trigDeg || trigFlags || 0 = radian angle mode ||
|-
| || ||1 = degree angle mode ||
|-
| plotLoc || plotFlags || 0 = write to display and buffer ||
|-
| || || 1 = write to display only ||
|-
| plotDisp || plotFlags || 0 = graph screen not in display ||
|-
| || || 1 = graph in display ||
|-
| grfFuncM || grfModeFlags || 0 = not function graph mode || Please note that the grfMode functions must have only 1 set and the rest reset; otherwise, the calculator will crash.
|-
| || || 1 = function graph mode ||
|-
| grfPolarM || grfModeFlags || 0 = not polar graph mode || Please note that the grfMode functions must have only 1 set and the rest reset.
|-
| || || 1 = polar graph mode ||
|-
| grfParamM || grfModeFlags || 0 = not parametric graph mode || Please note that the grfMode functions must have only 1 set and the rest reset.
|-
| || || 1 = parametric graph mode ||
|-
| grfRecurM || graphFlags || 0 = not sequence graph mode || Please note that the grfMode functions must have only 1 set and the rest reset.
|-
| || || 1 = sequence graph mode ||
|-
| graphDraw || grfDBFlags || 0 = graph is up to date ||
|-
| || || 1 = graph needs to be updated ||
|-
| grfDot || grfDBFlags || 0 = graph connected draw mode ||
|-
| || || 1 = graph dot draw mode ||
|-
| grfSimul || grfDBFlags || 0 = Draw functions one at a time ||
|-
| || || 1 = Draw all functions simultaneously ||
|-
| grfGrid || grfDBFlags || 0 = graph mode grid off ||
|-
| || || 1 = graph mode grid on ||
|-
| grfPolar || grfDBFlags|| 0 = Rectangular coordinates ||
|-
| || || 1 = Polar coordinates ||
|-
| grfNoCoord || grfDBFlags || 0 = graph coordinates off ||
|-
| || || 1 = graph coordinates on ||
|-
| grfNoAxis || grfDBFlags || 0 = graph draw axis ||
|-
| || || 1 = graph no axis ||
|-
| grfLabel || grfDBFlags || 0 = graph labels off ||
|-
| || || 1 = graph labels on ||
|-
| textEraseBelow || textFlags || 0 = Don't erase line below || Only on small text
|-
| || || 1 = erase line below ||
|-
| textInverse || textFlags || 0 = Regular text || Affects both small and large text
|-
| || || 1 = write in reverse video ||
|-
| onInterrupt || onFlags || 0 = No on-key interrupt || The on-key is interrupt driven but doesn't stop execution. Flag is set by the interrupt handler when the on-key is pressed.
|-
| || || 1 = On-key interrupt encountered ||
|-
| statsValid || statFlags || 0 = Stat results invalid ||
|-
| || || 1 = Stat results valid ||
|-
| fmtExponent || cell-content || 0 = Normal Mode || Either fmtExponent, fmtEng, or neither is set.
|-
| || || 1 = scientific display mode ||
|-
| fmtEng || fmtFlags || 0 = Normal Mode || Either fmtExponent, fmtEng, or neither is set.
|-
| || || 1 = engineering display mode ||
|-
| fmtReal || fmtFlags || 0 = Not real math mode || Either fmtReal, fmtRect,or fmtPolar must be set
|-
| || || 1 = real math mode ||
|-
| fmtRect || fmtFlags || 0 = Not rect complex math mode || Either fmtReal, fmtRect,or fmtPolar must be set
|-
| || || 1 = rect complex math mode ||
|-
| fmtPolar || fmtFlags || 0 = not polar complex math mode || Either fmtReal, fmtRect,or fmtPolar must be set
|-
| || || 1 = polar complex math mode ||
|-
| curAble || curFlags || 0 = Cursor flash disabled ||
|-
| || || 1 = Cursor flash enabled ||
|-
| curOn || curFlags || 0 = Invisible cursor ||
|-
| || || 1 = cursor is showing ||
|-
| curLock || curFlags || 0 = Cursor not locked ||
|-
| || || 1 = Cursor is locked off ||
|-
| appTextSave || appFlags || 0 = Don't write to textShadow || Places a copy of the character written to the display into the textShadow buffer.
|-
| || || 1 = Save characters written in textShadow ||
|-
| appAutoScroll || appFlags || 0 = Don't auto scroll || Scrolls text if on last line of large text
|-
| || || 1 = auto-scroll text on last line ||
|-
| indicRun || indicFlags || 0 = run indicator off ||
|-
| || || 1 = run indicator on ||
|-
| comFailed || getSendFlg || 0 = com did not fail ||
|-
| || || 1 = com failed ||
|-
| apdRunning || apdFlags || 0 = APD off ||
|-
| || || 1 = APD on ||
|-
| indicOnly || indicFlags || 0 = Run indicator not only priority || Sets the interrupt handler to update the run indicator, but not to process APD, blink the cursor, or scan for keys. It is useful when executing I/O link port operations for speed.
|-
| || || 1 = only update run indicator ||
|-
| shift2nd || shiftFlags || 0 = second key not pressed ||
|-
| || || 1 = second key pressed ||
|-
| shiftAlpha || shiftFlags || 0 = Normal mode ||
|-
| || || 1 = Alpha mode ||
|-
| shifLwrAlpha || shiftFlags || 0 = not lowercase mode || Alpha mode also active if set
|-
| || || 1 = lower case mode ||
|-
| shiftALock || shiftFlags || 0 = Not Alpha lock || Alpha mode also set
|-
| || || 1 = Alpha lock ||
|-
| grfSplit || sGrFlags || 0 = Normal graph mode || Either grfSplit, vertSplit, or neither must be set
|-
| || || 1 = horizontal graph split mode ||
|-
| vertSplit || sGrFlags || 0 = Normal graph mode || Either grfSplit, vertSplit, or neither must be set
|-
| || || 1 = vertical graph split mode ||
|-
| textWrite || sGrFlags || 0 = small font writes to display ||
|-
| || || 1 = small font writes to buffer ||
|-
| fullScrnDraw || apiFlag4 || 0 = Can't use column 95 or row 0 ||
|-
| || || 1 = allows draws to use column 95 and row 0 ||
|-
| bufferOnly || plotFlag3 || 0 = Draw to display and buffer ||
|-
| || || 1 = draw to graph buffer only ||
|-
| fracDrawLFont || fontFlags || 0 = small font with UserPutMap || Affects small text routines
|-
| || || 1 = draw large font in UserPutMap ||
|-
| customFont || fontFlags || 0 = Standard OS fonts ||
|-
| || || 1 = draw custom characters ||
|-
| lwrCaseActive || appLwrCaseFlag || 0 = Lowercase disabled for GetKey ||
|-
| || || 1 = enable lower case in GetKey loop ||
|-
| asm_Flag1_0 || asm_Flag1 || Your choice || Not used by the OS.
|-
| asm_Flag1_1 || asm_Flag1 || Your choice || Not used by the OS.
|-
| asm_Flag1_2 || asm_Flag1 || Your choice || Not used by the OS.
|-
| asm_Flag1_3 || asm_Flag1 || Your choice || Not used by the OS.
|-
| asm_Flag1_4 || asm_Flag1 || Your choice || Not used by the OS.
|-
| asm_Flag1_5 || asm_Flag1 || Your choice || Not used by the OS.
|-
| asm_Flag1_6 || asm_Flag1 || Your choice || Not used by the OS.
|-
| asm_Flag1_7 || asm_Flag1 || Your choice || Not used by the OS.
|-
| asm_Flag2_0 || asm_Flag2 || Your choice || Not used by the OS.
|-
| asm_Flag2_1 || asm_Flag2 || Your choice || Not used by the OS.
|-
| asm_Flag2_2 || asm_Flag2 || Your choice || Not used by the OS.
|-
| asm_Flag2_3 || asm_Flag2 || Your choice || Not used by the OS.
|-
| asm_Flag2_4 || asm_Flag2 || Your choice || Not used by the OS.
|-
| asm_Flag2_5 || asm_Flag2 || Your choice || Not used by the OS.
|-
| asm_Flag2_6 || asm_Flag2 || Your choice || Not used by the OS.
|-
| asm_Flag2_7 || asm_Flag2 || Your choice || Not used by the OS.
|-
| asm_Flag3_0 || asm_Flag3 || Your choice || Not used by the OS.
|-
| asm_Flag3_1 || asm_Flag3 || Your choice || Not used by the OS.
|-
| asm_Flag3_2 || asm_Flag3 || Your choice || Not used by the OS.
|-
| asm_Flag3_3 || asm_Flag3 || Your choice || Not used by the OS.
|-
| asm_Flag3_4 || asm_Flag3 || Your choice || Not used by the OS.
|-
| asm_Flag3_5 || asm_Flag3 || Your choice || Not used by the OS.
|-
| asm_Flag3_6 || asm_Flag3 || Your choice || Not used by the OS.
|}|

{{lowercase}}
[[Category:Z80 Assembly]]
[[Category:Z80 Heaven]]

Z80:System Flags - Revision history

Maintenance script: Initial automated import