Apple ImageWriter II - Manual (Page 23)

Missing, Jumbled, or Random Characters
These problems are caused by mismatched baud rates or mismatched data byte information (including
data byte length, parity, stop bit, and start bit settings).
Mismatched Data Transmission Rates
When the data transmission rate settings between devices are different, the printer can produce a
garbled printout. The ImageWriter II is set to 9600 baud at the factory.
Switches SW2-1 and SW2-2 should be in the closed, or down, position. If you own a Macintosh Plus,
Macintosh, or Apple IIc and are having a baud rate problem, check these switches.
If you have an Apple II, II Plus, or IIe, make sure your serial card is set to 9600 baud, unless you’re using
an Apple Serial Communications Card or other card set to 300 baud. If this is the case, you must reset the
ImageWriter II to 300 baud to receive the signal. Switches SW2-1 and SW2-2 should both be open for
300 baud. Check your interface card manual for baud rate details.
Never adjust switches or work with an interface card when the computer is on. You could harm the
computer and the interface card.
Mismatched Data Bytes
Data byte mismatches can occur through improper software and serial interface card settings. Data byte
mismatches include mismatches for the
data byte length
start bit
stop bit
parity setting
The ImageWriter II is permanently set for an eight-bit data byte with one start bit, one stop bit, and no
parity. Check your software settings for these categories. If you have an interface card, check its settings.
Intermittently Dropped or Random Characters
Mismatched communications protocols or a hardware failure (like a flawed connector or cable) can cause
intermittent problems.
Communications protocols tell a computer when to send data and when to pause in sending. A protocol
mismatch can cause intermittent loss of characters or intermittent garbage. The ImageWriter II is factory
set for the hardware handshake (also known as Data Terminal Ready or DTR) protocol. DIP switch SW2-3
should be set to Open. Closing this switch results in the XON/XOFF protocol.
Check the protocol settings for your software and for your interface card (if you have one).
Spacing Problems
Did the printout show the entire document printing on one line? Did the printer double- or triple-space
when you wanted single spacing? The problem is line feed. A line-feed character causes the printer to
advance the paper one line every time your software sends a carriage return (meaning the end of a line).
If the whole document printed on one line, it means that no line-feed character was sent to advance the