This is a text file generated
programmatically from the original Sinclair ZX Spectrum ROM. It
can be used as a source file by Zilog Z80 cross-assemblers to
generate a binary image of the Spectrum ROM for use in
Originally all comments were added automatically. These are gradually being converted to human comments to form a simple online reference that may assist you in any alterations you make to the Spectrum ROM.
Online ZX Spectrum Assembly File
The adventure continues! Secret Passageway discovered in ZX Spectrum at
This is featured in the new "Gosh Wonderful" ROM
The ZX range of computers run Minimal BASIC as their
As the assembly file is
quite large, download the Z80 source code for offline use.
ZX ROMs Assembly Files Collection Download
The file zx.zip contains zx82.txt, zx81.txt, zx80.txt, if1_1.txt, if1_2.txt and ace.txt.
As an example, zx82.txt assembles to zx82.obj
is 16384 bytes in length and may be used in your emulator
in place of the standard 16K ROM that came with it.
e.g. tasm -80 -b zx82.txt
If you are eager to see the benefits,
make the one-line change that cures the CHR$ 9 error and test
Don't stop there. You are in control now.
A temporary posting area for items of
interest to the Sinclair Community.
Patents, FAQ, Scans, Z80 Source, SOFT ROM and TS2068 files.
A complete assembly listing of the ROM of the Sinclair ZX81 / Timex TS-1000.
Note. that this is the "Improved" ZX81 ROM. You can read a list of the Differences at Stephen Agate's Emulator Homepage.
Note. an even earlier ROM has come to light. There are, as yet, no Bootleg copies of the ROM but this is the keyboard it would have used.
There is also my customized ZX81 ROM
variant which uses space-saving techniques to make way for
Newton's square root calculation, improved decimal number input
and consistent output to the screen and printer of floating point
The Shoulders of Giants ZX81 ROM Assembly.
Download the 8K ROM from here sg81.rom
A complete assembly listing of the
legendary Integer Basic Sinclair ZX80 ROM.
Perhaps the most influential computer program ever written.
or right-click this text file to save and compile your own version of the ZX80 ROM for use in emulators.
A rudimentry assembly listing of the
FORTH-based Jupiter Cantab Ace ROM.
By the author of the ZX Spectrum BASIC ROM.
Online Jupiter Ace ROM
or right-click this text file to save and compile your own version of the Jupiter Ace ROM for use in emulators.
Two assembly listings of the
Shadow ROM that gave Spectrum Users access to real printers,
fast storage devices and a Local Area Network.
Online Interface 1
ROM - version 1
Online Interface 1
ROM - version 2 - after serial number 87315
or click this link to download plain source code for use in emulators.
An adaptation of the standard assembly listing
of the Basic Sinclair ZX Spectrum ROM.
This is a major rework of the ROM which starts by relocating the System Variables where the ZX Printer buffer was. Don't expect much software to work as all the routine addresses are changed.
Online ZX Sea Change
ROM Assembly File Listing
These are the main features of the Sea Change ROM
This is a work-in-progress project so sometimes new features are introduced unintentionally. They shouldn't hang around too long and at the moment the ROM is believed to be completely bug-free. Get it here
right-click this text file to save and compile your own version of the ZX SEA CHANGE ROM for use in emulators.
visitors to this page.