Zeus Assembler#Monitor and disassembler

{{short description|Assembler development tool}}

{{Infobox software

| name = Zeus Assembler

| title =

| logo =

| logo caption =

| logo_size =

| logo_alt =

| screenshot =

| caption =

| screenshot_size =

| screenshot_alt =

| collapsible =

| author = Neil Mottershead
Simon Brattel

| developer = Crystal Computing

| released = {{Start date and age|1983}}

| discontinued = yes

| latest release version =

| latest release date =

| latest preview version =

| latest preview date =

| frequently updated =

| status =

| programming language =

| operating system =

| platform = ZX Spectrum

| size =

| language =

| language count =

| language footnote =

| genre = {{Plainlist|

| license = Proprietary commercial software

| alexa =

| website =

| standard =

| AsOf =

}}

Zeus Assembler is an assembler development tool for the Z80 originally written by Neil Mottershead for the Nascom 2 and then ported to the ZX Spectrum by Neil Mottershead and Simon Brattel in 1983. It was published by Crystal Computing. The program was designed to make Z80 machine code programming easier,"Six of the Best", ZX Computing, December–January 1983/84 issue(p.71), Argus Specialist Publications with full symbolic instructions, and an editing style similar to the Spectrum's built-in BASIC.

Zeus Assembler was later re-released by the manufacturer of the ZX Spectrum, Sinclair Research.

A Commodore 64 version was released in 1984. {{cite web |url=https://www.computinghistory.org.uk/det/56232/Zeus-64-Assembler/ |title=Zeus 64 Assembler}}

Overview

{{see also|Zilog Z80#Z80 assembly language}}

Zeus is a two-pass assembler which uses the standard Zilog Z80 instruction set mnemonics. It was one of the first assemblers to tokenise source code as it is entered, along with MAC/65 for the Atari 8-bit computers, similar to how many BASIC implementations work.

It has two command modes: assembler and editor,"Zeus Assembler review", Home Computing Weekly, issue 36 (p.52), Argus Specialist Publications, November 1983 and includes an auto line-numbering facility, and various subroutines for use within the user's programs, as well as printer output and basic assembler features such as labels and expressions."New Companies on the Sinclair Bandwagon", Sinclair User, issue 21 (p.64), ECC Publications, December 1983

Monitor and disassembler

The previous year Crystal Computing had released another machine code tool for the 16K ZX Spectrum called Monitor and Disassembler that could be used in conjunction with Zeus. While Zeus has a monitor included,"The Extended Spectrum", Big K, issue 9 (pp.70-71), IPC Business Press, December 1984 the more extensive Monitor and Disassembler allows for disassembly, the display and editing of the processor registers, as well as code substitution and the ability to move blocks of memory. Alongside Zeus, Monitor and Disassembler was later re-released by Sinclair Research.News, Home Computing Weekly, issue 29 (p.5), Argus Specialist Publications, September 1983

Reception

Zeus Assembler was well-received by the computing press. Your Computer praised it as well thought-out, with good auto-line number, renumber, and block delete functions."Spectrum Assemblers and Monitors", Your Computer, Vol. 3, No. 5 (pp.54-55), IPC Business Press, May 1985 Sinclair User and Big K highlighted the program's ease of use for beginners,[https://archive.org/details/sinclair-user-magazine-015] "Zeus Assembler Review", Sinclair User, issue 15 (p.29), ECC Publications, June 1983 while also being a very powerful tool in the hands of an expert. The necessity of exiting the assembler in order to save any generated code was cited as a potential drawback, especially for beginners.

Sinclair User also praised the documentation as the best of any assembler available at the time, for its use of step-by-step instructions and code examples.

Windows version

In 2008 Simon Brattel rewrote Zeus under the same name as a cross-assembler for Microsoft Windows together with integrated emulator and debugger. This was later bundled with various changes to help ZX Spectrum Next developers.

References

{{Reflist}}