This page is dedicated to the CP-500, a brazilian computer manufactured by Prologica during the 1980’s. Here you will find every information that you need to revive a realistic experience with that computer and also to get in touch with other people who share the same interest. Everything has been gathered in a single page, in order to make it more practical and useful.

The CP 500 is 100% compatible with the TRS-80, which means that all software developed for the American machine runs perfectly in the Brazilian one and vice-versa.

There is a significant community of TRS-80 fans in the US and around the world, and thanks to those people, software exist which allow the emulation of a TRS-80 in modern computers. Also, hundreds of TRS-80 floppy disks are available in the Internet in virtual form and those floppies can be used in emulators, reproducing the exact same behavior that you would expect from a real computer. Some emulators are so impressive that even the disk drive noises are reproduced, making you feel like if you were in front of a real machine!

Prologica Logo

Four CP 500 models were produced and, in regards to the TRS-80, the number is way larger. There are the TRS-80 models I, II, III, 4, the laptop versions 100, 102, 200, 600, the CoCos 1, 2, 3, the MC-10 and also eight different versions of Pocket Computers, not to mention the international clones among which the CP 500 is just one. Not all of these models are compatible among each other, so the table below shows the four CP 500 models ever created and their relationship to the American models of TRS-80.

Model Year CPU ROM RAM Text Graphics Compatibility
CP 500 1982 Z80 2MHz 16KB 48KB 64×16, 32×16 128×48 TRS-80 Model I/III
CP 500 M80 1985 Z80 2MHz 16KB or 2KB* 48KB or 64KB* 64×16, 32×16, 80×24 128×48 TRS-80 Model I/III/4
CP 500 M80C 1986 Z80 2MHz 16KB or 2KB* 48KB or 64KB* 64×16, 32×16, 80×24 128×48 TRS-80 Model I/III/4
CP 500 Turbo 1987 Z80 4MHz 16KB or 2KB* 48KB or 64KB* 64×16, 32×16, 80×24 128×48 TRS-80 Model I/III/4

*The CP 500 M80 and the models produced after that were equipped with a board that enabled them to run the CP/M operating system. The CP/M leaves 64KB of RAM available to the system and reduces the ROM addressing to only 2KB.

Alright, it’s time to see this beauty running, so here goes a list of everything you need to accomplish the task:

  • A TRS-80 emulator compatible with your operating system
  • A file containing a TRS-80’s ROM image to use in the emulator
  • A file containing a floppy image of a TRS-80 compatible operating system
  • More floppy images containing games, applications, utilities etc.
  • Operation manuals

Worry no more. In the following sections I present to you the best options available to fulfill each of these requirements. Also, save some time to check my Favorites page, where you will find a nice list of links to other TRS-80 pages around the world. If you want to get in touch with more TRS-80 fans, see the Discussion Groups in the end of that list.

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Let me save your time and recommend the best emulators I know:

Name: TRS32Author: Matthew Reed
OS: Windows
Description: This program emulates the TRS-80 Model I, III, 4, and 4P. The CPU emulation is extremely accurate, supports all known instructions, and runs at exact TRS-80 speed. It is also extremely fast, being written in assembly language, and can exceed actual TRS-80 speed on any computer capable of running Windows. The floppy disk emulation is incredibly accurate and will even work great with self-booting or protected disks, such as Super Utility.
Page: www.trs-80emulators.com

Name: xtrs
Author: Tim Mann
OS: Unix
Description: xtrs is a Radio Shack TRS-80 Model I/III/4/4P emulator for Unix and the X Window System. It includes lower case, the real time clock, hi-res graphics, serial port, parallel printer, mouse, cassette, sound and music output (requires OSS), 5″ and 8″ floppy disk drives in single and double density, and even hard disk drives.
Page: tim-mann.org

Author: Mark Grebe
OS: Mac OS
Description: sdltrs is a Radio Shack TRS-80 Model I/III/4/4P emulator for Macintosh OSX, Windows, and Linux. It has been ported from Tim Mann’s excellent X-Windows UNIX emulator xtrs. Instead of using the X-Window system for graphics, it uses the portable SDL library.
Page: sdltrs.sourceforge.net

Author: Peter Phillips
Description: This web page emulates a TRS-80 Model III using only Javascript. This emulator is really a testament to the extreme speed of modern computers and the astounding new Javascript interpreters. The combination can easily emulate the function of the TRS-80 running at 2MHz. That’s well over 100,000 emulated instructions per second!.
Page: people.cs.ubc.ca/~pphillip

Name: Other
Author: Other
OS: Other
Description: If you need an emulator for other operating systems, I suggest that you research the trs-80.com website. Ira Goldklang maintains a list of all known emulators along with the links for downloading them.
Page: www.trs-80.com

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ROM Images

Thanks to the Prof. Gustavo E. A. P. A. Batista, the CP 500 community had access to the first image of a CP 500 ROM extracted directly from the computer chips with an EPROM reader. The CP 500 ROM has 16KB unlike the 14 KB found in the TRS-80. According to an analysis made by Matthew Reed, these 2KB extra contains the Z80 resident monitor, which appears to be an exclusive feature of the CP 500. A comparison between both ROMs also showed that only 90 bytes differ, mostly because of translated messages from English to Portuguese.

Because the Z80 monitor occupies a memory range conflicting with video and keyboard addresses of the original TRS-80, this feature does not work in the TRS32 emulator. For some unknown reason, to access the CP 500 ROM (like when you turn on the computer without floppies in the drives) you must first boot the emulator with a DOS500 disk and then reboot it again without disks. Maybe there is something in the DOS code that “enables” the ROM.

If you are a happy owner of a CP 500 and wishes to extract a ROM image by yourself, you can use the following code written in Disk BASIC:

10 OPEN "O",1,"CP500/ROM"
30 CLOSE 1

In case you don’t have a real machine to extract a ROM image, you can download it from here:

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Operating Systems

The most interesting about the 1980’s is that the market wasn’t dominated by one or two operating systems as it is today. For a TRS-80 or CP-500 you could use any of the following operating systems:

  • DOS500 (Prologica)
  • DOSPLUS (Micro-Systems Software)
  • LDOS (Misosys)
  • MULTIDOS (Cosmopolitan Elec.)
  • NewDOS/80 (Apparat)
  • OS-80 III (Percom)
  • RapidOS (Rapidynamic Software)
  • TRSDOS (Tandy)
  • CP/M (Digital Research)

Below you will find links to download some of these operating systems. Others can be found in the web sites indicated in the Links section ahead.

DOS500_ LDOS_ RapidOS_
DOS 500 LDOS RapidOS

TRSDOS NewDos80 MultiDOS


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Assorted Software

It is really pleasant to realize that a computer equipped with a 8-bit 2 MHz processor and 48 kB of memory is capable of doing so many interesting things. Among the software available for the CP-500 you can find:

  • BASIC, Pascal, C, COBOL, APL, Assembly and other language compilers
  • Text processors (SuperScripsit, Allwrite, HyperTyper etc.)
  • Spreadsheets (Visicalc)
  • Databases (Profile III+, Data Handler, AIDS-III etc.)
  • Graphics & Sound (Speech Synthesizer, Organ Synthesizer, MDraw, Power Draw etc.)
  • Utilities (Copycat, Hyperzap, Super Utility, Floppy Doctor etc.)
  • Games (Robot Attack, Crazy Painter, Outhouse, Meteor Mission, Lunar Lander etc.)

Below you will find links to download some of these softwares. Many others can be found in the web sites indicated in the Links section ahead.

Demon_ Clone_ Chicken_
Painter_ MusicBox_ Apps_Hyperzap

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Operation Manuals

The CP-500 came with two manuals, one targeting the computer operation and BASIC programming and the other oriented to the use of the DOS500 operating system. Luckly, digital copies of both of them (written in Brazilian Portuguese) can be found in the Internet. Also, other technical manuals about the TRS-80 are available on-line. Below you will find links to the main technical references about the CP-500. Other documents can be obtained in the web sites indicated in the Links section ahead.
Also a very rare to find technical manual written in Portuguese by Prologica is here, thanks Luccas.

BASIC_ DOS-500_ TechRef_

Service_ Diags_ Manual_Tecnico_CP500


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cp-12 cp-13



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Discussion Groups

Forum: CP-500
Host: Google
Language: Portuguese
Description: Fórum brasileiro criado recentemente e que reúne proprietários e fãs do CP-500 para a troca de informações e outros itens

Forum: comp.sys.tandy
Host: Usenet
Language: English
Description: From about Tandy, focus on TRS-80 I/III/4.

Forum: TRS-80
Host: Yahoo
Language: English


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http://www.cp500.com.br (CP-500 “Mdutra”)
http://www.datacassete.com.br (Data Cassete)
http://www.emuladores.com.br (Emuladores)
http://www.lojinhadomoises.com.br (Lojinha do Moises)
http://www.luccas.com.br/site (Luccas Eletronica)
http://www.revistavintage.info (Revista Vintage)
http://www.poucosbits.com (Pouco Bits)


Note: The original text was written by mdutra.com. Some texts have been updated and/or changed.