MDOS (short for Myarc Disk Operating System) is an

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

commercialized by Myarc. It was designed and implemented specifically for the

Geneve 9640 The Geneve 9640 is an enhanced TI-99/4A clone. It was sold by the company Myarc as a card to fit into the Texas Instruments TI Peripheral Expansion System. Released in 1987, it is in many ways similar to the earlier TI-99/8, which was in prototyp ...

by Paul Charlton. MDOS was designed to fully emulate the

TI-99/4A The TI-99/4 and TI-99/4A are home computers released by Texas Instruments in 1979 and 1981, respectively. Based on the Texas Instruments TMS9900 microprocessor originally used in minicomputers, the TI-99/4 was the first 16-bit home computer. T ...

computer while providing an advanced (for its time) virtual memory operating environment with full support for mouse,

GUI The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...

, and complex mathematical applications. In 1993, Beery Miller the publisher of 9640 News, organized a group of Geneve 9640 owners and was able to purchase all rights to the source code for MDOS,

Advanced Basic The IBM Personal Computer Basic, commonly shortened to IBM BASIC, is a programming language first released by IBM with the IBM Personal Computer, Model 5150 (IBM PC) in 1981. IBM released four different versions of the Microsoft BASIC interpre ...

, the PSYSTEM runtime module, and the GPL Interpreter from Myarc and Paul Charlton. Over the years, MDOS has been updated by individuals including T. Tesch, Clint Pulley, Alan Beard, John Johnson, James Schroeder, Mike Maksimik, James Uzzell, Tony Knerr, Beery Miller, and others. Support adding

SCSI Small Computer System Interface (SCSI, ) is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, electrical, optical and logical interface ...

, IDE, and larger ramdisks were added in the earlier years from the buyout. In late 2020 and early 2021 with the release of the TIPI for the TI-99/4A, the Geneve was interfaced with the TIPI and a

Raspberry Pi Raspberry Pi () is a series of small single-board computers (SBCs) developed in the United Kingdom by the Raspberry Pi Foundation in association with Broadcom. The Raspberry Pi project originally leaned towards the promotion of teaching basic ...

providing TCP socket access and nearly unlimited high speed hard-drive like file access. A small but active base of users still exist on www.Atariage.com as of 2021 where T. Tesch, Beery Miller, and others provide support. MDOS was written specifically for the TMS9995 16-bit CPU and the

Yamaha V9938 The Yamaha V9938 is a video display processor (VDP) used on the MSX2 home computer, as well as on the Geneve 9640 enhanced TI-99/4A clone and the Tatung Einstein 256. It was also used in a few MSX1 computers, in a configuration with 16kB VRAM ...

video display processor. All source code for the Geneve 9640 is in the

public domain The public domain (PD) consists of all the creative work to which no exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly waived, or may be inapplicable. Because those rights have expired, ...

External links

Myarc Geneve 9640 Family ComputerMyarc Geneve 9640 Software9640News Software
- a close look at the system board and sales flyer

* ttp://hometown.aol.com/swim4home/geneve2.html Geneve items@ Richard Bell's Company
Photo of Geneve 9640 booting
- HD-based vertical PEB system belonging t
Photo of Geneve showing swan image
- fro

- mixed Geneve 9640 and TI-99/4A photos
Geneve 9640
- at old-computers.com * elnet://heatwave.ddns.net:9640 Heatwave BBS- Telnet BBS operating on a Myarc Geneve 9640 under MDOS. {{Disk operating systems TI-99/4A Products introduced in 1987 Proprietary operating systems Disk operating systems