The TRS-80 model II, is the obscure brother of the TRS-80 family. Many internet pages deal with the models 1,3 and 4 but omit the model 2... This is maybe because the TRS-80 Model 2 was intended to be a business computer for use in offices and labs. Thus it is equiped with a full height Shugart 8'' drive with a capacity of 500k which is a lot compared to the 87k offered by the TRS-80 Model 1 system disk.
It is also possible to connect up to 4 floppy disk units, so you could have 2MB disk space online !
It runs under TRSDOS, but can also achieve CP/M compatibility.
Options for the machine included a hard disk controller, an arcnet network card, a graphics card and a 6 MHz 68000 board set with extra memory (up to 512K) so it could run XENIX.
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Mark Brumlik reports to us:
Actually, there was a Hi-Res Graphics Mode for this machine, which mapped every pixel on the screen (still in monochrome). There was very limited software for it.
The machine had the capacity in hardware to utilize multiple 64K banks of memory but this was never implemented in production software. This is the same techiique the IBM PC and other clone 8-bit machines achieved 640K of memory (10 banks of 64K).
Edward Griffin adds:
This machine could also read IBM formatted Mainframe and data entry unit disks. The data entry units (IBM 3742's I think) would write information directly to 8 inch floppys as the operater depressed the Carriage Return button, and then the disks could be taken from these large units and insterted into the drive of the model II for verification and other checking. I recall a Model II being expressly used for this purpose. It also came with a neat Radio Shack acoustic coupler!!
These machines did experiance frequent power supply problems though!
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I had a Model II with a 10MB hard drive. It was a separate unit in a matching case, so the twin 8" drives were also usable. And it was the size of a PC lying in its side, if a little less wise. I remember opening it up for a look-see and finding a belt driving the hard drive and the motor off to one side. This when all in one drives such as we see today were becoming the norm.
I had quite a bit of software for it: Scripsit, DBase and BASIC, all running off TR-DOS, plus some CP/M disks which were (sadly) corrupted.
Friday 17th January 2014
JonB
To Tom94022: The Shugart Hard Drives were sold in a separate box. The HD units could also be used with the Model III and 4 too as I recall. They also had a key lock on them for security.
Sunday 5th December 2010
Chuck Rose (USA)
In late 70's I developed a lot commercial software (accounting, insurance, etc.) for this machine (in Basic, with several critical routines written in Z80 machine language) and my company sold several of TRS-ModII. The problems with power supply involved mainly a tantalium condenser in the video card, which caused a black-out of the screen. On the other hand, it was a very good computer for its time.
Tuesday 6th November 2007
Sergio Internicola (Italy)
NAME
TRS 80 MODEL II
MANUFACTURER
Tandy Radio Shack
TYPE
Professional Computer
ORIGIN
U.S.A.
YEAR
May 1979
BUILT IN LANGUAGE
Basic delivered on disk
KEYBOARD
Full-stroke keyboard with separated numeric keypad
CPU
Zilog Z80 A
SPEED
4 MHz
RAM
32 / 64 KB depending on models
ROM
Unkown
TEXT MODES
40 x 24 / 80 x 24
GRAPHIC MODES
None, but 32 graphical symbols are available to simulate graphics
COLORS
monochrome built-in monitor
SIZE / WEIGHT
Heavy !
I/O PORTS
Centronics/Parallel port, 2 x serial/RS232 ports
BUILT IN MEDIA
One full height Shugart 8'' drive, single sided floppies with a capacity of 500K
