Editing ABC 80

{{Short description|1979 home computer}}
{{More citations needed|date=July 2020}}
{{Infobox information appliance
| name = ABC 80
| title = 
| aka = Advanced BASIC Computer 80
| logo = 
| image = ABC 80 Personal Computer.jpg
| caption =
| developer = [[Dataindustrier AB]] (DIAB)
| manufacturer = [[Luxor AB]]
| family = 
| type = [[Home computer]]
| generation = 
| releasedate = {{Start date and age|1978}}
| lifespan = 
| price = 
| discontinued = 
| unitssold = 
| unitsshipped = 
| media = 
| os = 16&nbsp;KB ROM with Luxor [[BASIC]]<ref name="greentacblog_080701">{{cite web|title=Greentac Blog: July 2008 |url=http://www.greentacblog.com/2008/07/ancient-computer.html |url-status=dead |archiveurl=https://web.archive.org/web/20080911105932/http://www.greentacblog.com/2008/07/ancient-computer.html |archivedate=September 11, 2008 }} 090502 greentacblog.com</ref>
| power = 
| soc = 
| cpu = [[Zilog Z80]] @ 3&nbsp;[[Hertz|MHz]]<!-- 2.9952 MHz http://mess.toseciso.org/mess:drivers:abc80:abc80 -->
| memory = 16–32&nbsp;KB RAM + separate screen memory
| storage = 
| memory card = 
| display = 12-inch monochrome monitor,<ref name="greentacblog_080701" /> Text mode 40×24 [[monochrome]] [[Teletext]]<ref name="toseciso_drivers_abc80">{{cite web|title=mess:drivers:abc80:abc80 [MESS DevWiki] |url=http://mess.toseciso.org/mess:drivers:abc80:abc80 |url-status=dead |archiveurl=https://web.archive.org/web/20090223103039/http://mess.toseciso.org/mess%3Adrivers%3Aabc80%3Aabc80 |archivedate=2009-02-23 }} 090502 mess.toseciso.org</ref>
| graphics = 78×72 block graphics<ref name="toseciso_drivers_abc80" /> (equivalent resolution of 312×287 @ 50 Hz)<ref name="toseciso_drivers_abc80" />
| sound = 1-channel [[Texas Instruments SN76477|SN76477]]<ref name="toseciso_drivers_abc80" />
| input = 
| controllers = 
| camera = 
| touchpad = 
| connectivity = Tape recorder, relay, display/sound/power, {{nowrap|2×32 pin CPU bus}} (4680), [[RS-232]]
| platform = 
| service = 
| dimensions = 
| weight = 
| topgame = 
| compatibility = 
| predecessor = 
| successor = 
| related = 
| website = <!--{{URL|example.org}}-->
}}

The '''ABC 80''' ('''Advanced BASIC Computer 80''') is a [[home computer]] engineered by the Swedish corporation [[Dataindustrier AB]] (DIAB) and manufactured by [[Luxor AB|Luxor]] in [[Motala]], [[Sweden]] in the late 1970s and early 1980s.<ref>{{Cite web |title=Advanced BASIC Computer 80 |url=https://www.mediaarchaeologylab.com/collection/advanced-basic-computer-80-e04ab4c |access-date=2023-02-23 |website=The Media Archeology Lab |language=en}}</ref> It was introduced on the market in August 1978.<ref>{{Cite web |last=Rautiainen |first=Sami |date=February 13, 2020 |title=The History of Luxor ABC |url=http://www.devili.iki.fi/Computers/Luxor/history.en.html |access-date=2023-02-23 |website=www.devili.iki.fi}}</ref>

The ABC 80 was based on an earlier modular computer system from the same company<ref>This system was called ''DIAB Data Board 4680'' and could initially also use the 4004 or 6800 CPUs before the newer Z80 CPU was available.</ref> and built around a [[Zilog Z80|Z80]] and {{nowrap|16 KB}} of [[Read-only memory|ROM]] containing a fast semi-compiling [[BASIC]] [[Interpreter (computing)|interpreter]]. It had {{nowrap|16–32 [[Kilobyte|KB]]}} of [[random-access memory|RAM]] as [[main memory]] and a dedicated (included) tape recorder for program and data storage, but could also be expanded to handle disk drives as well as many other peripherals.  The ROM could be extended in increments of 1 or 4&nbsp;KB in order to handle such so called "options". The [[computer monitor|monitor]] was a black and white [[television set|TV set]] modified for the purpose, an obvious choice since Luxor also made TVs.

The ABC 80 was used in schools and offices around Scandinavia and parts of Europe.<ref>{{Cite web |title=ABC 80 Luxor |url=https://www.old-computers.com/museum/computer.asp?st=1&c=37 |access-date=2023-02-23 |website=www.old-computers.com}}</ref> It was also used for [[industrial automation]], [[science|scientific]] [[measurement]] and [[control system]]s. Like its successor, the [[ABC 800]], the computer had an unusually quick and usable BASIC with excellent I/O response times, something that was often discovered when trying to switch to [[IBM Personal Computer|IBM PC]]-based [[personal computer]]s. Due to its roots in an industrial computer system, the ABC 80 also had a flexible [[bus (computing)|bus extension]] system with many (external) expansion and peripheral cards available for various purposes and applications, as well as high quality support and documentation.

ABC 80 was also manufactured on license as '''BRG ABC80''' by ''Budapesti Rádiótechnikai Gyár'' in [[Hungary]].<ref>{{Cite web |title=East-European Home-Computer Hungary |url=http://www.homecomputer.de/pages/easteurope_hu.html |access-date=2023-02-23 |website=Home Computer Museum}}</ref> It used the same keyboard, but the case was metal instead of plastic.

== Popularity ==
In addition to its widespread use in schools, offices and industrial applications, the {{nowrap|ABC 80}} initially also grasped a majority share of the rising personal computer market in [[Sweden]], partly thanks to its [[office software]] in [[Swedish language|Swedish]]. The computer was robust and well engineered, mechanically and electrically, and its BASIC was fast enough that it could be used to write [[arcade game]]s, without resorting to [[assembly language]]. However, despite such technical virtues, it couldn't defend the home market against the dedicated gaming computers with color and sound that appeared in the early 1980s, neither against the cheap ultra simplistic [[home computer]]s of the same era,<ref>With the [[VIC 20]] and the [[ZX81]] being typical examples, respectively.</ref> even though a new low cost version was released that could use an ordinary [[Television set|TV]] instead of the dedicated monitor.

[[Luxor AB|Luxor]] (and Facit) held on to its more professional markets for some more years with the ABC 800 series (also sold as Facit DTC). It had a more extensive BASIC, more memory, color, and a 512×240 graphics mode. From 1985 DIAB and [[Luxor AB|Luxor]] also tried to compete against the [[IBM Personal Computer|IBM PC]] in the industrial and office markets with its high performance [[ABC 1600]] and ABC 9000 series of computers based on DIABs [[real-time operating system]] called [[DNIX]], but failed.

However, many ABC 80 and ABC 800 machines used in industrial or scientific applications were in use in their respective installations for many years to come, sometimes well into the late 1990s, despite no longer being produced.<ref>This was practical enough as the ABC 80 as well as most I/O, peripheral, and expansion cards used almost no custom designed parts. Most of the ROM, DRAM and SRAM memory ICs were socketed and replaceable for many years. The Z80 family and most of the [[integrated circuit]]s in the 74-series used to implement the logic are actually still readily available, as of 2016.</ref>

== Performance ==
In order to see how the ABC 80 would compare to other contemporary personal computers, in 1982, the Swedish magazine ''[[MikroDatorn]]'' ran the [[Rugg/Feldman benchmarks]] of eight short BASIC programs (referred to as BM1~BM8) originally published by the American ''[[Kilobaud Microcomputing]]'' magazine and routinely used by the British magazine [[Personal Computer World]] for testing new machines. The result was that ABC 80's interpreter turned out to be faster than most other BASICs used in popular machines, especially when [[integer]] variables are used, the results for some well known computers were as follows (times in seconds, lower is better):

{| class="wikitable"
|- 
! Computer              || [[Central processing unit|CPU]] || &#91;[[Hertz|MHz]]&#93; ||BM1 ||BM2 ||BM3 ||BM4 ||BM5 ||BM6 ||BM7 ||BM8
|-
| ABC 80 Integer
|rowspan="2"| [[Zilog Z80|Z80]]
|rowspan="2"| 3   ||0.3 ||1.1 ||3.5 ||3.5 ||3.6 ||5.8 ||9.3 ||65
|-
| ABC 80 Floating point ||1.0 ||2.1 ||11.0 ||11.0  ||12.5 ||17.5 ||24.0 ||130
|-
| colspan="11"|&nbsp;
|-
| [[IBM PC]] || [[Intel 8088|8088]] || 4.77  <!-- Assumed!! --> ||1.5 ||5.2 ||12.1||12.6||13.6||23.5||37.4||35
|-
| [[Apple III]] || [[Synertek|S6502]] || 2 ||1.7 ||7.2 ||13.5||14.5||16.0||27.0||42.5||75
|-
| [[VIC-20]] || [[MOS Technology 6502|6502]] || 1.108 || 1.4 ||8.3 ||15.5||17.1||18.3||27.2||42.7||99
|-
| [[ZX81]] in "fast mode" || [[Zilog Z80|Z80]] || 3.25 || 4.5 || 6.9 || 16.4 || 15.8 || 18.6 || 49.7 || 68.5 || 229
|}

The ABC 80 was  up to {{nowrap|4.7 times}} as fast as the [[IBM PC]] using integers and up to {{nowrap|2.5 times}} as fast using [[floating point]] math. However, due to a sub-optimal [[exponentiation]] [[algorithm]], the ABC 80 was slow on BM8 (which was fixed in the [[ABC 800]]). Compared to the [[ZX81]], the ABC 80 was {{nowrap|15 times}} as fast on the simple loop of BM1 (with the ZX81 running in ''fast'' mode, i.e. without a continuous TV-picture).

== Sound ==
* [[Sine]], [[noise]], [[Square wave (waveform)|square wave]]. And [[Electronic mixer|mixing]] these.<ref>ABC80 manual page 36</ref><!-- Port 6 "OUT 6,X -->
* Quick [[envelope (music)|decay]], sine overlay, high or low tone, pulse tone control, on and off.

== Books ==
The circuitry in the ABC 80 is described in detail in the book ''Mikrodatorns ABC'' (''The microcomputer ABC''), by [[Gunnar Markesjö]]. It starts off with a course in digital electronics and microcomputer principles (assuming some general knowledge in electronics) and then presents a large number of block diagrams and partial circuit schematics, covering most of the computer, along with detailed explanations of how it works and why certain solutions were chosen.

== See also ==
* [[ABC 800]]
* [[ABC 1600]]
* [[Compis]]

== References ==
{{Reflist}}

== External links ==
* [https://www.abc.se/ ABC user group] (in Swedish)

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[[Category:Z80-based home computers]]
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[[Category:Computer-related introductions in 1978]]