IBM 1800 Operating Procedures Manual page 41

IBM 1443 Printer
The IBM 1443 Printer provides high-speed on-line printing
capabilities for the 1800 system. fhe 1443 (maximum of
one per system) is a buffered prin ter and operates under
data channel controL
The data to be printed must be edited and arranged in
main storage in the exact form that it is to be printed. One
complete line of data is transferred via a data channel to
the 1443 print buffer for each write operation. When a
complete line is transferred to the buffer, the 1443 prin ts
the line.
Alphabetic, numeric, and special characters are located
on a bar that travels back and forth in a horizontal plane.
To print, a magnet releases a spring-loaded hammer at the
proper time so the desired character is pressed against the
ribbon and paper (Figure 12).
Four distinct character sets are available. The character
set and 1443 Model (lor 2) determine the printing speed
as shown in the following table.
Character
Li nes per Mi nute
Set
1443 - 1
1443 - 2
13 430 600
39 190 300
52
150 240
63 120
200
The 52-character set is standard. A selective character
feature must be ordered for any other character set.
Carriage
The carriage is tape controlled and advances the form as
indicated by the stored program. Vertical spacing is man-
ually set for either six or eight lines to the inch. The car-
riage can be single, double, or triple spaced. These oper{l-
tions are planned in the program when spacing operations
are required.
38
IBM 1800 Operating Procedures
The c:lrriage commands give flexibility to spacing opera-
tions by providing linespacing and forms skipping on an
immediate or delayed basis. The commands are used with
a control tape which is arranged to identify the format of
the form being used.
The carriage is a tractor-feed type with no provisions
for pressure feeding documents. Therefore, the forms
must be continuous with marginal punching on both edges.
Forms can be from 4 to 16-3/4 inches in overall width.
Maximum form depth is 22 inches at six lines per inch
vertical spacing or 16-1/2 inches at eight lines per inch
vertical spacing.
Figure 12. 1443 Printing Schematic
Reverse Side of
i + - - -
Typebar Segment
I