Redirecting printer output in DOS: Which DOS command correctly configures printing so that LPT1 output is redirected to the serial port COM1?

Introduction / Context:
Legacy applications often send print jobs to parallel ports (LPT1). When only a serial printer is available, DOS can redirect output from LPT1 to COM1 using the MODE command. Correct syntax is vital for successful redirection.

Given Data / Assumptions:

• Goal: redirect LPT1 jobs to COM1.
• DOS provides the MODE utility for device configuration and redirection.
• Printer and serial parameters may require additional MODE settings (baud, parity) after redirection.

Concept / Approach:

Use MODE to bind logical devices. The canonical form is MODE LPTn=COMm. After binding, any program printing to LPT1 actually transmits data through COM1, assuming compatible serial settings.

Step-by-Step Solution:

Verification / Alternative check:

After redirection, issuing a print test results in activity on the serial port. Documentation for MODE shows the LPT-to-COM mapping syntax exactly as above.

Why Other Options Are Wrong:

• Parallel serial, Direct LPT1=COM1, MODE printer ()-serial (): Not valid DOS syntax.
• None of the above: Incorrect because MODE LPT1=COM1 is correct.

Common Pitfalls:

Forgetting to set serial parameters to match the printer, or overlooking that some applications bypass DOS and talk directly to hardware (rare), which can defeat redirection.

Final Answer:

MODE LPT1=COM1