====== Tandy/Radio Shack TRS-80 Model I (1977) ======
===== Features =====
* CPU: Zilog Z80 1.77 MHz
* RAM: 4 kb / 16 kb depending on models (up to 48 kb)
* VRAM: 1 kb
* ROM: 4 kb (Basic Level 1) or 12kb (Basic Level 2)
* Text Modes: 32 x 16, 64 x 16
* Graphic Modes: 128 x 48
* Colors: monochrome
* Sound: None
* I/O Ports: Monitor, cassette interface, expansion port
* Keyboard: Full-stroke keyboard, 53 Keys, optional numeric keypad
* OS: TRS DOS - NEW DOS
* Built In Language: Basic Level 1 (4k ROM models), Basic Level II (12k ROM models)
===== Usage =====
== Keyboard ==
The emulated keyboard is relatively close to the original layout.
Take a look into the "Options" menu, accessible by hitting TAB, and choose "Keys (This Machine)" to find out more about the key mapping.
== Cassettes ==
Emulation of virtual tapes supported. Use
SYSTEM
or
CLOAD
commands to read images.
SYSTEM supports 6 character filenames and loads the corresponding FILENM.CAS image.
CLOAD loads a file named BASIC(N).CAS, where (N) is the character you supplied (e.g. CLOAD"M" loads BASICM.CAS)
== Disks ==
Emulation of virtual floppy discs supported. Use a NEWDOS/80 boot disk for drive 0 and set up correct PDRIVE parameters for the other drives. If only drives 0 to 2 are used they can be double sided by interpreting drive select 3 as head select bit.
Under the "Options" menu, accessible by hitting TAB, there are three settings.
* "Floppy Disc Drives" - enable or disable floppy disc controller.
* "Video RAM" - enable upper case only or upper/lower font.
* "Virtual E000-EFFF" - enable 4K Extension ROM or make it RAM.
===== Known Issues =====
The TRS-80 driver should run most of the known programs out there. It supports a WD 179x floppy disc controller with up to four virtual floppy disc drives contained in image files.
===== History and Trivia =====
The Tandy TRS-80 model 1, released in August 1977 at a US retail price of $399 for just the keyboard/computer or $599 including display and cassette storage unit, was the first member of one of the most famous computer families.The earliest models used a poor BASIC interpreter called Basic Level 1 (the interpreter and the OS fit in the 4 KB ROM) which had no instruction to save the program! It was replaced later with the Basic Level 2 which needed a 12 KB ROM. To offset its poor characteristics, Tandy developed a device called the Expansion Interface which brought a lot of new features: 16, 32 or 48 KB RAM, two tape unit connectors, a printer port, a floppy disk controller, a serial port and a real time clock.
When it was connected to a floppy disk unit, the TRS 80 used the TRS DOS operating system, it was pretty bugged and most of the TRS80 users preferred NEW DOS, it is an operating system done by a third-party company called Apparat. This OS was the real TRS 80 operating system.
The Model 1 was followed with the TRS 80 model II and model III (the model III had almost the same characteristics as the model I).
===== Links =====
* Ira Goldklang's Page -- http://www.trs-80.com/
* Timm Mann's TRS-80 Page -- http://www.tim-mann.org/trs80.html
* TRS-80 Model I at old-computers.com -- http://old-computers.com/museum/computer.asp?c=409
===== Other Emulators =====
* David Keil's TRS-80 Model I Emu -- http://discover-net.net/~dmkeil/trs80/model1.htm
* Jeff Vavasour's TRS-80 Model I Emu -- http://www.vavasour.ca/jeff/trs80.html#model1
* TRS32 -- http://www.arrowweb.com/mkr/
* TRSF-80 -- http://members.aol.com/trsf80/
Generated on Sun Jul 19 10:17:28 2009