|Commodore 4022 serial
507856 made in Japan.
| A slow and very
noisy dot matrix printer for PETs. A Commodore version
of an Epson printer, it uses a tractor feed and
continuous paper to produce a low quality result
up to 80 characters wide. Printing is in one direction
only rather than bi-directionally as in later printers,
meaning that the print head has to return to the
left edge before printing each line. True descenders
are not possible, so the letters g, j, p, q and
y sit on the line rather than having their tails
| The printer connects
to the IEEE port and if used with a disk drive must
be last in line. Originally there was a paper tray
attached to the printer.
serial 6 04488 made in Japan.
| Also slow and
noisy, a dot matrix printer available at the same
time as the VIC 20. The 1525 like the earlier 1515
is a Seikosha adapted for Commodore. The printer
uses a tractor feed and continuous paper. Useful
for listing programs, the printer produces a low
quality result. True descenders are not possible.
The plastic cover actually reduces the noise level
- to plain deafening!
| This printer
connects to the serial port and if used with disk
drives must be last in line. At the back of the
printer (above right) is a switch with the options
from left to right: T (test print), 5 (device number
5, selected if this is the second printer) and 4
(device number 4, selected if this is the first
or only printer). Next to this is the serial connector.
serial XH5027737 made in Japan.
| One of the most
common Commodore dot matrix printers. The MPS803
has only 7 pins and so, like the 1525, cannot print
true descenders. This printer can be daisy-chained,
that is other serial connections can be added to
it. At the back (above right) are two switches.
The left one is used to select device number 4 (switch
to the left) or 5 (switch to the right). The one
on the right is the paper feed pitch selector (one
sixteenth inch when switched to the left, one eighth
to the right). Beside these are two serial sockets,
one to connect to the computer, the other to add
other printers or disk drives.
serial 0060221990 made in Italy.
| The MPS1230 has
a 9 pin resolution and a better print quality as
a result. Shown here with a sheet feeder, the printer
can be converted to take continuous paper with the
supplied adaptor. As well as the serial connector,
the 1230 has a parallel interface (above right)
and so can be used with a variety of computers.
serial 2203921-77 made in Japan.
| This is a Citizen
printer with a Commodore badge, and my favourite
type. The 120-D allows near letter quality (NLQ)
printing and a high level of options. The printer
has the ability to take a selection of cartridges
for different makes of computer and with the Commodore
interface (below right) prints the full range of
PET characters. It can take continuous paper (above
left) or individual pages (above right). Still noisy
by today's standards, it was a huge improvement
over its predecessors.
|Citizen 120-D serial
number BU018022 made in the UK.
| The Citizen 120-D
can be adapted for use with a wide range of computers.
I've fitted mine with a Commodore interface. Unlike
its well used Commodore counterpart, this one has
Printer-Plotter AJ5 014612 (Japan).
|A tube of pens
and the pens with their caps.
| The 1520 has
four small replaceable pens, black, red, blue and
green. The pens are tricky to install and must be
removed from the printer after use to avoid drying
out. The 1520 takes a roll of paper and can be used
to plot graphs or to list programs. I never really
found a use for it but it can produce good graphics.
| All of my printers,
except the 1520, are of the dot matrix type. Text
or graphics are produced by a column of pins which
print or leave a space as required, moving across
the paper as they do so. The print quality depends
on the number of dots and how close they are together.
| The Commodore
1525 in fact has only one pin, or rather a hammer.
This moves in and out as required by the software.
Behind the paper is a revolving drum or "platen".
This has ridges on its surface. Where a dot is required,
the print head strikes the ribbon which is then
pressed against the paper and the platen. The position
of each dot (or not) depends on whether or not a
ridge is present on the platen.
| Early dot matrix
printers like the Vic-1525 and the MPS803 cannot
properly print letters like g, j, p, q and y because
the bottom of each letter is on the same line. This
gives an adequate result for program listings but
is insufficient for most other purposes.
| Better quality
from nine pins on the MPS1230 and better still in
NLQ (near letter quality) mode with the 120-D. This
latter gives a result similar to that of an electric
typewriter, used in offices until the arrival of
the pc. The 120-D allows the printing of true descenders
because there are two rows of pins below the line.