NotesAddressNameDescription
HexDec
X25B5A23386RETADDRReturn address in ROM 1
X15B5C23388BANKMCopy of last byte output to I/O port 7FFDh (32765). See Chapter 23 – The Memory. This byte must be kept up to date with the last value output to the port if interrupts are enabled
X15B5D23389RAMRSTRST 8 instruction. Used by ROM 1 to report old errors to ROM 3
N15B5E23390RAMERRError number passed from ROM 1 to ROM 3. Also used by SAVE/LOAD as temporary drive store
15B5F23391INKLINK colour for LoRes
15B6023392INK2INK colour for Layer 2
15B6123393ATTRULAAttributes for standard mode
15B6223394ATTRHRAttributes for HiRes (only paper colour in bits 5:3 is used)
15B6323395ATTRHCAttributes for HiColour
15B6423396INKMASKSoftcopy of EnhancedULA InkMask (or 0)
N15B6523397LSBANKTemporary bank number in LOAD/SAVE and other operations
15B6623398FLAGS3Various 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
X15B6723399BANK678Copy of last byte output to I/O port 1FFDh (8189). This port is used to control the +3 extended RAM and ROM switching (bits 0..2 – if bit 0 is 0 then bit 2 controls the 'vertical' ROM switch 02 and 13), the disk motor (bit 3) and Centronics strobe (bit 4). This byte must be kept up to date with the last value output to the port if interrupts are enabled
X15B6823400FLAGNFlags for the NextZXOS system
15B6923401MAXBNKMaximum available RAM bank
X25B6A23402OLDSPOld SP (stack pointer) when TSTACK is in use
X25B6C23404SYNRETReturn address for ONERR
55B6E23406LASTVLast value printed by calculator
15B7323411TILEBNKLTiles bank for LoRes
15B7423412TILEMLTilemap bank for LoRes
15B7523413TILEBNK2Tiles bank for Layer2
15B7623414TILEM2Tilemap bank for Layer2
X15B7723415NXTBNKBank containing NXTLIN
X15B7823416DATABNKBank containing DATADD
15B7923417LODDRVHolds 'T' if LOAD, VERIFY, MERGE are from tape, otherwise holds 'A', 'B' or 'M'
15B7A23418SAVDRVHolds 'T' if SAVE is to tape, otherwise holds 'A', 'B' or 'M'
N15B7B23419L2SOFTSoftcopy of Layer 2 port
25B7C23420TILEWLWidth of LoRes tilemap
25B7E23422TILEW2Width of Layer 2 tilemap
25B8023424TILEOFFLOffset in bank for LoRes tilemap
25B8223426TILEOFF2Offset in bank for Layer 2 tilemap
25B8423428COORDSXX Coordinate of last point plotted (Layer 1/2)
25B8623430COORDSYY Coordinate of last point plotted (Layer 1/2)
15B8823432PAPERLPAPER colour for LoRes mode
15B8923433PAPER2PAPER colour for Layer 2 mode
Nx5B8A23434TMPVARSBase of temporary system variables (space shared with bottom of TSTACK)

ZX Spectrum Next User Manual, 3rd Edition (ISBN 978-1-5272-5496-1), written and illustrated by Phoebus R. Dokos. Copyright © 2020-2024 Phoebus Dokos / SpecNext Ltd. Licensed under CC BY-NC-SA 4.0. This is a transcription and can contain errors; check any doubt against the printed page.