System 80 Models and Variants
following text details the form, function and various manifestations of
the System 80. As the index above suggests, the machine went through several
evolutionary variations. These were relatively minor, amounting mostly
to incompatibility fixes and incorporating features which were available
in earlier models as add-ons (such as lower case).
The interesting thing about these releases
(apart from the Mark II) was that they were never publicised or heralded.
The case still bore the simple name "System 80" with no version
number to indicate the changes inside. The business model had the legend
"Mark II" on the case but the names for the Mark I variants
were ones that were given by users themselves. I've used the terms, v.1
and v.2 to distinguish between the different variants of the Mark I.
Those who want to take a closer look at
the System 80 and what's inside can click
2.0 The System 80 Mark I (version 1)
Dick Smith Electronics Ltd was the sole
supplier of the System 80 to Australia and New Zealand, at least for 1980
and 1981. EACA also sold the machine to distributors in Western
Europe as the Video Genie, and it appeared in the North American market
A brand new System-80 retailed at about
$NZ1200 or $A800 (about $US500). It came with
Like the Model 1, the System-80 had a
full-stroke keyboard but there the visual similarities ended. The latter
was housed in an attractive sloping case, with tapering plastic wood-veneer
sides. The keys were white, set in a black surround. The case itself was
cream and black. Unlike the TRS-80 Model 1, the System 80 had the cassette
recorder, RF modulator (so you could plug it straight into a TV) and power
supply all built-in to the unit. With the early System 80s, if you looked
closely you could see that two of the keys were missing, i.e. the CLEAR
and Right Arrow key. The equivalent of the Up arrow in the Model I was
called ESC, the down key (coloured grey) was CNTL and the Left Arrow key
was called BACK SPACE. The ENTER Key was called NEW LINE.
Around the back of the unit was the on/off
switch (on the right), the reset button (on the left) and a button called
"Video cut" (about the middle).
The photo above shows the ports on the
back LHS (The socket and switch at the right-hand top is a hardware modification
by the previous owner). The Video Cut button "cut" the video
display in half, displaying the first 32 characters in a much larger font
(handy for those less-than-ideal TV's).
The second, right-hand side of the output
(also in the large font) could be viewed by pressing a grey button above
the keyboard called PAGE. Just to the right of PAGE was a twin button
labeled F1. Depressing it switched the cassette recorder on so that users
could position the tape manually with the control buttons.
Under the hood, the System-80's specifications
were very similar to the TRS-80 Model 1. The unit was powered with a Zilog
Z80 microprocessor running at 1.79Mhz and boasted 16K memory on-board.
It ran a version of Microsoft Basic which was the same as that in the
Tandy Radio Shack TRS-80 model 1 machines. Characters were displayed on
the screen 64 wide by 16 deep and graphics mode was the same 128 x 48
grid as the latter. Interfacing was done either through the second cassette
port, or a 50-pin expansion bus unique to the System-80. This bus could
interface with an optional System-80 expansion unit, offering 32K of extra
memory, disk drives, a centronics-compatible parallel printer port and
Early System 80s had upper case only,
but later models included lower case. Like the TRS-80 model 1, it suffered
from keyboard bounce, which could be cured with either disk or cassette-based
For those of a more technical persuasion,
I've included on this site scanned pages
from the System 80 Technical Manual.
Differences between the original System 80 and the TRS-80 Model 1
- In the first release, two keys were absent, the CLEAR
and the Right Arrow key (a serious deficiency for game players but
rectified in the later System-80 release)
- The 32 character mode was achieved by way of the
switch at the back of the unit called "Video Cut". A button
on the top of the unit called "Page" showed the other 32
characters on the (now invisible) right-hand side of the screen.
The normal way of achieving 32-character mode in the TRS-80 Model
1 was to use the BASIC command CHR$(23). In the System 80 all this
did was to put a space after each character, effectively making the
video display 32 characters wide, but with the same font as before.
- The unit had a built-in cassette deck and a second
cassette port. The latter was only found on the expansion interface
of the Model 1.
- An RF Modulator was built-in so you could plug the
unit straight into a TV set.
- The "arrow keys" and ENTER had different
labels (discussed above)
- The computer also showed different symbols corresponding
to the arrow ASCII codes. The Up Arrow was "[", the Down
Arrow was "\", the Left Arrow was "]" and the
Right Arrow was "^". Similar to the TRS-80 Model 3.
- At non-disk boot-up "Memory size?" was
"Ready?" and no copyright notices appeared when BASIC initialised.
- The printer port was addressed differently. The System-80
used the I/O address "FD" whereas that in the TRS-80 used
memory address "37E8". This meant patching machine language
programs like SCRIPSIT to get them to work.
- The serial interface was also addressed differently.
In the System-80, I/O addresses "F8" and "F9"
were used, whereas the TRS-80 used memory addresses "37DE"
- Switching between the two cassettes recorder ports
differed in the use of addresses
Assembly-code aficionados wishing to explore
the System-80 ROM calls can download and read Eddy Paay's (TRS-80 Model
1) Level II
ROM Reference Manual from this site, and then can click
here to see the exact ROM differences between the System-80 and the
A frank and detailed review of the original
System-80 (from the pages of Micro-80) can be found here.
Another review (this one from 80-Microcomputing) can be read on www.trs-80.com
Mark I (version 2a and b)
The biggest headaches for users of TRS-80
software on the new System-80s was the absence of the two "missing"
keys (used by most games) and the built-in cassette deck with no volume
control, which often failed to load programs.
Realising the problems with their new
microcomputer were not insignificant, Dick Smith Electronics Ltd took
an active lead in trying to fix them. They produced Technical Bulletins
on how to modify systems to overcome
these difficulties, and many owners with soldering skills took up the
challenge. DSE technical staff (notably Technical Service Manager
Garry Cratt, Jim Rowe and Rex Callaghan) also spent a lot time visiting
EACA, working to improve that company's quality control, which left a
lot to be desired.
Jim Rowe pushed EACA to restore the two
missing keys and also lead the charge for a gain meter and volume control
to make tape loading more reliable. The latter was resisted by EACA
who thought they could solve the tape loading problem by other means,
but in the end they gave into DSE's insistence.
then, the two (glaring!) deficiencies were addressed in late 1980 when
System-80s (version 2a) started to ship with a TAB (i.e Right Arrow) and
a CLEAR key. This had been achieved by substituting the large right hand
shift key, with two buttons, a re-located BACKSPACE key, and a TAB key.
CLEAR was placed where the BACKSPACE used to be, just above NEW LINE.
Also included was the cassette volume control and gain meter discussed
above, allowing users to monitor and adjust cassette output. Tape loading
was still slow but much less frustrating.
You can see the added keys and the cassette
deck additions in the associated photo.
It was one of these machines that
introduced me to the world of the System-80 (and TRS-80ism in general)
in 1981. This improved version was a big hit and many units were sold
throughout New Zealand and Australia that year.
After October, 1981 the units started
to ship with lower case fitted (version 2b). Like most of the System-80
improvements, this was completely unheralded and buyers were often unaware
of the inclusion until they ran a lower-case driver! Another difference
related to the keys. BACKSPACE, TAB, ESC and CNTL were replaced
with arrow keys. This had a certain irony as (unlike the TRS-80
Model 1) there were no arrow characters in the System-80 character set!
However, as software game instructions (written primarily for the TRS-80
Model 1 rather than the System 80 specifically) often referred to "the
arrow keys", it was good sense to show users just which keys these
were. Especially now they were all present!
Mark II (business model and "Educator")
1981, the world of personal computing had not yet split into "home"
or "business" camps, but the seeds of this dichotomy were beginning
to germinate. At the same time the second version of the System-80 was
released, EACA also released a business model, subtitled the Mark II.
This model (which had also been instigated by DSE's Jim Rowe) replaced
the built-in cassette deck with a numeric keypad. It also included lower
case, which the standard System-80 units did not have (although lower-case
kits were available and, invariably, added to older units). Other extras
included an expanded ROM containing the lower-case driver, auto repeat,
flashing cursor and a screen print function. It also provided terminal
features and function keys. The RF modulator found in the Mark I
line was absent.
The System-80 business model was designed
to be used with an expansion unit, monitor and disk drives, although it
did retain a cassette port (as did the original IBM-PC!).
"solution" packages were promoted with this model. Interestingly,
Dick Smith used this machine to flirt briefly with the education market.
A new face plate and it became the System
80 Mk II Educator Computer.
In 1982 a forth (and the last) variant
of the System-80 appeared. While still a member of the Mark I lineage,
this model featured a blue faceplate and hence gained the suffix "blue-label".
The System-80 blue-label boasted a number
of refinements over the previous Mark I "black-labels". First,
lower case was fitted as standard. Secondly, as with the Mark II,
extra ROM was included to make use of the unused 2K of memory which lay
beyond the BASIC interpreter and the start of RAM. The blue label machine
provide a 1.5k ROM/EPROM which featured a simple machine language monitor
(for a debug mode), flashing cursor, auto-repeat keyboard, screen print
and key de-bounce. Thirdly, the unit had build-in sound!
Although the TRS-80 Model 1 was never
designed to feature sound, machine language TRS-80 games invariably featured
it. This was generated as output through the AUX lead to the tape recorder,
and when this lead was plugged into an amplifier, sound effects could
be heard. However, in the System-80, cassette deck one #1 was built-in
and there was no AUX output! To hear sound effects, older System-80 owners
had to fit a small switch which allowed sound to be sent to the AUX output
through cassette port #2 (and hence to the outside world). The blue-label
solved this problem by including a small amplifier and speaker in the
unit itself. One problem though, was that there was no volume control,
much to the dismay of many parents, flatmates and spouses.
Finally, the keyboard was also slightly
different to previous models. The CLEAR key was moved up beside
the BACKSPACE key. In its place were the left and right arrow keys,
having being moved there from below the NEW LINE key. That space
was now occupied by a second SHIFT key, just as it had been with the original
By the time the blue-label appeared, the
microcomputer world was breaking into two camps. A developing home market,
with it's emphasis on colour and sound, was being serviced by a plethora
of low-cost games computers. The business world had discovered small computers
could be useful devices when running Visicalc and Wordstar, and was standardising
on a growing number of characterless but reliable CP/M workhorses.
The System-80 could not satisfy either
camp and so, despite the sophisticated Model I/III DOS's available (compared
to CP/M), history closed the book on this versatile computer, as it had
on the Genre maker, the Model 1 two years before. The last System-80's
rolled off the production line sometime mid-1983. By then over 13,000
units had been sold in Australia and had made "a fortune" for
DSE (Dick Smith's own words!).
Curiously, at some stage a few "black
label" units appeared in New Zealand with the name C/MICRO rather
than System 80 emblazoned across the front. These appear to have
been imported and badged by a small (one man?) company called "Dynamic
Applications". Other units appeared called P/Micro sold by
an Auckland company. Clearly, Dick Smith wasn't the only Australasian
retailer doing business with EACA although these other distributors may
have been later entrants. Dick Smith electronics held the exclusive
Australasian distribution rights, at least until 1982.
Dick Smith Electronics Ltd went on to
market a colour computer in 1982, the VZ-200 (called the Laser in Britain).
With small rubber keys and little software, it was one among the plethora
of cheap, colour home computers sold at that time.
A Z80-based colour
computer, marketed under EACA's own name, was produced in 1982. Although
the specs looked reasonable, it was not TRS-80 compatible and, lacking
a software base and any concentrated marketing effort, the machine was
Why did Dick Smith Electronics pick up
on the VZ-200 rather than the EACA colour computer? There were two
reasons. One was the very good relationship DSE had with
the manufacturers of the VZ-200, another Hong Kong supplier
called Video Technology, who had released a games console marketed as
the Dick Smith Wizzard in earlier times. The other was that the
EACA machine was a higher price, and margins were not so attractive.