IBM 5103 Dot matrix printer



IBM 5103 Dot matrix printer

The IBM 5103 printer is the only printer that can be attached to an IBM 5100, 5110 or 5120 computer. There are two versions of the printer: one with 80 cps and one with 120 cps.



Print head

The print head contains 8 needles (or "dots") that are arranged in a vertical row. While printing one byte of the character, depending on the column within the character, is read from the ROS and used to drive the needle magnets. Because of the latency a needled can only be driven each second printing position (like the middle bar in the character A in the following drawing). As a character is seven dots wide there are seven bytes per character to be read from the ROS. The eighth byte is always zero to retract all needles and prepare them for the next character.

Printing of the character A


Data flow diagram of the printer adapter card

Data flow diagram

Control commands

Reset Set Function Reset Set Function
1090Forms go latch 51D1Enable timer interrupts
93Not forms motor latch A and B 52Reset timer interrupt
97Forms motor latch A D4Enable 3.3ms or 2.66ms interrupt
9BForms motor latch B 54D4Enable print fire (5110)
9FForms motor latch A and B 54Enable 1.1ms interrupt
1191Enable forms interrupt (5110) 41C1Enable not ready interrupt
12Reset forms interrupt (5110) 42Reset not ready interrupt
20A0Print go latch 58D8Allow ROS addressing
Enable print emitter interrupts D8Preset timer counter (5110)
22Reset print emitter interrupt ECROS address byte 0
A3Not print motor latches A and B 6CROS address byte 1
A7Print motor latch A E4ROS address byte 2
ABPrint motor latch B 64ROS address byte 3
AFPrint motor latches A and B E8ROS address byte 4
80Both motors on (both go latches on) 68ROS address byte 5
00Both motors off (both go latches off) E0ROS address byte 6
60ROS address byte 7

Schematic diagrams

The following images have been scanned with 300 dpi from the IBM 5103 MIM (No. SY31-0414-3) and are too large to view them on screen.