Johnnyo: added legend

2025-05-04T01:58:23Z

added legend

← Older revision		Revision as of 02:58, 4 May 2025
Line 368:		Line 368:

	\|}		\|}


			The meaning of the codes in the column 1 of the table:
			; X : The variable should not be changed, the system might crash.
			; N : Changing the variable will have no lasting effect
			; R : Routine entry point. The content should not be changed.

Johnnyo: adding the variables starting with $5B00

2025-05-04T01:45:26Z

adding the variables starting with $5B00

← Older revision		Revision as of 02:45, 4 May 2025
Line 2:		Line 2:

	! Status/width !! Address !! Mnemonic !! Description		! Status/width !! Address !! Mnemonic !! Description
			\|-

			\| R16 \|\| $5B00 \|\| SWAP \|\| Paging subroutine.
			\|-

			\| R17 \|\| $5B10 \|\| STOO \|\| Paging subroutine. Entered with interrupts already disabled and AF, BC on the stack.
			\|-

			\| R9 \|\| $5B21 \|\| YOUNGER \|\| Paging subroutine.
			\|-

			\| R16 \|\| $5B2A \|\| REGNUOY\|\| Paging subroutine.
			\|-

			\| R24 \|\| $5B3A \|\| ONERR \|\| Paging subroutine
	\|-		\|-

Julian S at 15:39, 26 April 2019

2019-04-26T15:39:55Z

← Older revision		Revision as of 16:39, 26 April 2019
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	\|-		\|-

	\| *N1 \|\| $5B68 \|\| FLAGN \|\| Flags for the ~~NextOS~~ system.		\| *N1 \|\| $5B68 \|\| FLAGN \|\| Flags for the NextZXOS system.
	\|-		\|-

Line 70:		Line 70:
	\|-		\|-

	\| *1 \|\| $5B75 \|\| TILEBNK2 \|\| Tiles bank for ~~layer2~~.		\| *1 \|\| $5B75 \|\| TILEBNK2 \|\| Tiles bank for Layer 2.
	\|-		\|-

Line 88:		Line 88:
	\|-		\|-

	\| 2 \|\| $5B7C \|\| TILEWL \|\| Width of lo-res tilemap		\| 2 \|\| $5B7C \|\| TILEWL \|\| Width of Lo-res tilemap
	\|-		\|-

	\| 2 \|\| $5B7E \|\| TILEW2 \|\| Width of ~~layer2~~ tilemap		\| 2 \|\| $5B7E \|\| TILEW2 \|\| Width of Layer 2 tilemap
	\|-		\|-

	\| 2 \|\| 5B80H \|\| TILEOFFL \|\| Offset in bank for lo-res tilemap		\| 2 \|\| 5B80H \|\| TILEOFFL \|\| Offset in bank for Lo-res tilemap
	\|-		\|-

	\| 2 \|\| $5B82 \|\| TILEOFF2 \|\| Offset in bank for ~~layer2~~ tilemap		\| 2 \|\| $5B82 \|\| TILEOFF2 \|\| Offset in bank for Layer 2 tilemap
	\|-		\|-

Line 115:		Line 115:
	\|-		\|-

	\| 1 \|\| $5B8E \|\| INKL \|\| INK colour for lo-res mode		\| 1 \|\| $5B8E \|\| INKL \|\| INK colour for Lo-res mode
	\|-		\|-

	\| 1 \|\| $5B8F \|\| INK2 \|\| INK colour for ~~layer2~~ mode		\| 1 \|\| $5B8F \|\| INK2 \|\| INK colour for Layer 2 mode
	\|-		\|-

Line 124:		Line 124:
	\|-		\|-

	\| 1 \|\| $5B91 \|\| INKHR \|\| INK colour for hi-res mode		\| 1 \|\| $5B91 \|\| INKHR \|\| INK colour for Hi-res mode
	\|-		\|-

	\| 1 \|\| $5B92 \|\| ATTRHC \|\| Attributes for hi-colour mode		\| 1 \|\| $5B92 \|\| ATTRHC \|\| Attributes for Hi-colour mode
	\|-		\|-

Specnext: 1 revision imported

2019-04-14T10:00:22Z

1 revision imported

← Older revision		Revision as of 11:00, 14 April 2019
(No difference)

wiki>Hyphz: Created page with "{| class="wikitable" ! Status/width !! Address !! Mnemonic !! Description |- | X2 || $5B52 || OLDHL || Temporary register store while switching ROMs. |- | X2 || $5B54 || OL..."

2017-10-08T18:30:46Z

Created page with "{| class="wikitable" ! Status/width !! Address !! Mnemonic !! Description |- | X2 || $5B52 || OLDHL || Temporary register store while switching ROMs. |- | X2 || $5B54 || OL..."

New page

{| class="wikitable"

! Status/width !! Address !! Mnemonic !! Description
|-

| X2 || $5B52 || OLDHL || Temporary register store while switching ROMs.
|-

| X2 || $5B54 || OLDBC || Temporary register store while switching ROMs.
|-

| X2 || $5B56 || OLDAF || Temporary register store while switching ROMs.
|-

| N2 || $5B58 || TARGET || Subroutine address in ROM 3.
|-

| X2 || $5B5A || RETADDR || Return address in ROM 1.
|-

| X1 || $5B5C || BANKM || Copy of last byte output to {{PortNo|$7FFD}}. This byte must be kept up to date with the last value output to the port if interrupts are enabled.
|-

| X1 || $5B5D || RAMRST || RST 8 instruction. Used by ROM 1 to report old errors to ROM 3.
|-

| N1 || $5B5E || RAMERR || Error number passed from ROM 1 to ROM 3. Also used by SAVE/LOAD as temporary drive store.
|-

| 2 || $5B5F || BAUD || RS232 bit period in T states/26. Set by FORMAT LINE.
|-

| N2 || $5B61 || SERFL || Second-character-received-flag, and data.
|-

| N1 || $5B63 || COL || Current column from 1 to WIDTH.
|-

| 1 || $5B64 || WIDTH || Paper column width. Defaults to 80.
|-

| 1 || $5B65 || TVPARS || Number of inline parameters expected by RS232.
|-

| 1 || $5B66 || FLAGS3 || Various flags. Bits 0, 1, 6 and 7 unlikely to be useful. Bit 2 is set when tokens are to be expanded on printing. Bit 3 is set if print output is RS232. The default (at reset) is Centronics. Bit 4 is set if a disk interface is present. Bit 5 is set if drive B: is present.
|-

| X1 || $5B67 || BANK678 || Copy of last byte output to {{PortNo|$1FFD}}. This byte must be kept up to date with the last value output to the port if interrupts are enabled.
|-

| *N1 || $5B68 || FLAGN || Flags for the NextOS system.
|-

| *N1 || $5B69 || MAXBNK || Maxmium available RAM bank number.
|-

| X2 || $5B6A || OLDSP || Old SP (stack pointer) when TSTACK is in use.
|-

| X2 || $5B6C || SYNRET || Return address for ONERR.
|-

| 5 || $5B6E || LASTV || Last value printed by calculator.
|-

| *1 || $5B73 || TILEBNKL || Tiles bank for Lores.
|-

| *1 || $5B74 || TILEML || Tilemap bank for Lores.
|-

| *1 || $5B75 || TILEBNK2 || Tiles bank for layer2.
|-

| *X1 || $5B77 || NXTBNK || Bank containing NXTLIN.
|-

| *1 || $5B78 || DATABNK || Bank containing DATADD.
|-

| 1 || $5B79 || LODDRV || Holds 'T' if LOAD, VERIFY, MERGE are from tape, otherwise holds 'A', 'B' or 'M'.
|-

| 1 || $5B7A || SAVDRV || Holds 'T' if SAVE is to tape, otherwise holds 'A', 'B' or 'M'.
|-

| 1 || $5B7B || L2SOFT || Soft copy of {{PortNo|$123B}}
|-

| 2 || $5B7C || TILEWL || Width of lo-res tilemap
|-

| 2 || $5B7E || TILEW2 || Width of layer2 tilemap
|-

| 2 || 5B80H || TILEOFFL || Offset in bank for lo-res tilemap
|-

| 2 || $5B82 || TILEOFF2 || Offset in bank for layer2 tilemap
|-

| 2 || $5B84 || COORDSL || x,y coords of last point plotted (lo-res)
|-

| 2 || $5B86 || COORDS2 || x,y coords of last point (layer 2)
|-

| 2 || $5B88 || COORDSULA || x,y coords of last point (standard)
|-

| 2 || $5B8A || COORDSHR || x,y coords of last point (hi-res)
|-

| 2 || $5B8C || COORDSHC || x,y coords of last point (hi-colour)
|-

| 1 || $5B8E || INKL || INK colour for lo-res mode
|-

| 1 || $5B8F || INK2 || INK colour for layer2 mode
|-

| 1 || 5B90H || ATTRULA || Attributes for standard mode
|-

| 1 || $5B91 || INKHR || INK colour for hi-res mode
|-

| 1 || $5B92 || ATTRHC || Attributes for hi-colour mode
|-

| 1 || $5B93 || INKMASK || Softcopy of {{NextRegNo|$42}} (or 0)
|-

| N8 || $5B94 || STRIP1 || Stripe one bitmap
|-

| N8 || $5B9C || STRIP2 || Stripe two bitmap
|-

| X91 || $5BFF || TSTACK || Temporary stack grows down from here. Used when RAM page 7 is switched in at top of memory (while executing the editor or calling +3DOS). It may safely go down to $5B9D (and across STRIP1 and STRIP2 if necessary).
|-

| N8 || $5C00 || KSTATE || Used in reading the keyboard.
|-

| N1 || $5C08 || LASTK || Stores newly pressed key.
|-

| 1 || $5C09 || REPDEL || Time (in 50ths of a second) that a key must be held down before it repeats.
|-

| 1 || $5C0A || REPPER || Delay (in 50ths of a second) between successive repeats of a key held downs.
|-

| N2 || $5C0B || DEFADD || Address of arguments of user defined function (if one is being evaluated), otherwise 0.
|-

| Nl || $5C0D || K DATA || Stores 2nd byte of colour controls entered from keyboard.
|-

| N1 || $5C0E || TVDATA || Stores bytes of colour, AT and TAB controls going to TV.
|-

| X38 || $5C10 || STRMS || Addresses of channels attached to streams.
|-

| 2 || $5C36 || CHARS || 256 less than address of character set (which starts with space and carries on to (C)). Normally in ROM, but you can set up your down in RAM and make CHARS point to it.
|-

| 1 || $5C38 || RASP || Length of warning buzz.
|-

| 1 || $5C39 || PIP || Length of keyboard click.
|-

| 1 || $5C3A || ERRNR || 1 less than the report code. Starts off at 255 (for -1) so 'PEEK 23610' gives 255.
|-

| X1 || $5C3B || FLAGS || Various flags to control the BASIC system.
|-

| X1 || $5C3C || TVFLAG || Flags associated with the TV.
|-

| X2 || $5C3D || ERRSP || Address of item on machine stack to be used as error return.
|-

| N2 || $5C3F || LISTSP || Address of return address from automatic listing.
|-

| N1 || $5C41 || MODE || Specifies 'K', 'L', 'C', 'E' or 'G' cursor.
|-

| 2 || $5C42 || NEWPPC || Line to be jumped to.
|-

| 1 || $5C44 || NSPPC || Statement number in line to be jumped to. Poking first NEWPPC and then NSPPC forces a jump to a specified statement in a line.
|-

| 2 || $5C45 || PPC || Line number of statement currently being executed.
|-

| 1 || $5C47 || SUBPPC || Number within line of statement currently being executed.
|-

| 1 || $5C48 || BORDCR || Border colour multiplied by 8; also contains the attributes normally used for the lower half of the screen.
|-

| 2 || $5C49 || E PPC || Number of current line (with program cursor).
|-

| X2 || $5C4B || VARS || Address of variables.
|-

| N2 || $5C4D || DEST || Address of variable in assignment.
|-

| X2 || $5C4F || CHANS || Address of channel data.
|-

| X2 || $5C51 || CURCHL || Address of information currently being used for input and output.
|-

| X2 || $5C53 || PROG || Address of BASIC program.
|-

| X2 || $5C57 || NXTLIN || Address of next line in program.
|-

| X2 || $5C57 || DATADD || Address of terminator of last DATA item.
|-

| X2 || $5C59 || E LINE || Address of command being typed in.
|-

| 2 || $5C5B || K CUR || Address of cursor.
|-

| X2 || $5C5D || CH ADD || Address of the next character to be interpreted - the character after the argument of PEEK, or the NEWLINE at the end of a POKE statement.
|-

| 2 || $5C5F || X PTR || Address of the character after the [] marker.
|-

| X2 || $5C61 || WORKSP || Address of temporary work space.
|-

| X2 || $5C63 || STKBOT || Address of bottom of calculator stack.
|-

| X2 || $5C65 || STKEND || Address of start of spare space.
|-

| N1 || $5C67 || BREG || Calculator's B register.
|-

| N2 || $5C68 || MEM || Address of area used for calculator's memory
|-

| 1 || $5C6A || FLAGS2 || More flags. (Bit 3 set when CAPS SHIFT or CAPS LOCK is on.)
|-

| X1 || $5C6B || DF SZ || The number of lines (including one blank line) in the lower part of the screen.
|-

| 2 || $5C6C || S TOP || The number of the top program line in automatic listings.
|-

| 2 || $5C6E || OLDPPC || Line number to which CONTINUE jumps.
|-

| 1 || $5C70 || OSPPC || Number within line of statement to which CONTINUE jumps.
|-

| N1 || $5C71 || FLAGX || Various flags.
|-

| N2 || $5C72 || STRLEN || Length of string type destination in assignment.
|-

| N2 || $5C74 || T ADDR || Address of next item in syntax table (very unlikely to be useful).
|-

| 2 || $5C76 || SEED || The seed for RND. This is the variable that is set by RANDOMIZE.
|-

| 3 || $5C78 || FRAMES || 3 byte (least significant byte first), frame counter incremented every 20ms.
|-

| 2 || $5C7B || UDG || Address of first user-defined graphic
|-

| 1 || $5C7D || COORDS || X-coordinate of last point plotted.
|-

| 1 || $5C7E || || Y-coordinate of last point plotted.
|-

| *1 || $5C7F || GMODE || Graphical layer/mode flags.
|-

| X2 || 5C80h || PRCC || Full address of next position for LPRINT to print at (in ZX printer buffer). Legal values 5B00 - 5B1F.
|-

| 2 || $5C82 || ECHO E || 33-column number and 24-line number (in lower half) of end of input buffer.
|-

| 2 || $5C84 || DF CC || Address in display file of PRINT position.
|-

| 2 || $5C86 || DF CCL || Like DF CC for lower part of screen.
|-

| X1 || $5C88 || S POSN || 33-column number for PRINT position.
|-

| X1 || $5C89 || || 24-line number for PRINT position.
|-

| X2 || $5C8A || SPOSNL || Like S POSN for lower part.
|-

| 1 || $5C8C || SCR CT || Counts scrolls - it is always 1 more than the number of scrolls that will be done before stopping with 'scroll'?
|-

| 1 || $5C8D || ATTR P || Permanent current colours, etc., (as set up by colour statements).
|-

| 1 || $5C8E || MASK P || Used for transparent colours, etc. Any bit that is 1 shows that the corresponding attribute bit is taken not from ATTR P, but from what is already on the screen.
|-

| N1 || $5C8F || ATTR T || Temporary current colours, etc., (as set up by colour items).
|-

| N1 || 5C90h || MASK T || Like MASK P, but temporary.
|-

| 1 || $5C91 || P FLAG || More flags.
|-

| N30 || $5C92 || MEMBOT || Calculator's memory area - used to store numbers that cannot conveniently be put on the calculator stack.
|-

| 2 || $5CB0 || NMIADD || Holds the address of the users NMI service routine.
|-

| 2 || $5CB2 || RAMTOP || Address of last byte of BASIC system area.
|-

| 2 || $5CB4 || P RAMT || Address of last byte of physical RAM.
|-

|}

System Variables - Revision history

Johnnyo: added legend

Johnnyo: adding the variables starting with $5B00

Julian S at 15:39, 26 April 2019

Specnext: 1 revision imported

wiki>Hyphz: Created page with "{| class="wikitable" ! Status/width !! Address !! Mnemonic !! Description |- | X2 || $5B52 || OLDHL || Temporary register store while switching ROMs. |- | X2 || $5B54 || OL..."