Editing Atari Portfolio Troubleshooting Guide (section)

== Serial and Parallel Interface Issues ==

=== Smart Parallel Interface (HPC-101) ===

<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table"
|+ Parallel Interface Troubleshooting
|-
! Symptom !! Likely Cause !! Action
|-
| File transfer fails || Incorrect cable or software not loaded || Requires the Atari File Transfer software on the PC side. Use a standard '''DB25 male-to-male''' parallel cable (HPC-406). Ensure the PC has a true parallel port (USB adapters may not work).
|-
| Printing fails || Wrong cable type || Printing requires a '''DB25 male-to-Centronics 36-pin male''' cable (CB101287), not the file transfer cable.
|-
| Interface not detected || Dirty expansion port contacts || Clean the Portfolio expansion port contacts and the interface module contacts with IPA.
|-
| Rapid battery drain with interface attached || Normal behaviour || The parallel interface draws significant power. '''Always use the AC adapter''' when using the parallel port.
|}

=== Serial Interface (HPC-102) ===

<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table"
|+ Serial Interface Troubleshooting
|-
! Symptom !! Likely Cause !! Action
|-
| No communication || Incorrect serial settings || Default settings: 9600 baud, 8 data bits, no parity, 1 stop bit. Verify both ends match. The HPC-102 supports 110–9600 baud.
|-
| Garbled text || Baud rate mismatch or cable issue || Ensure both devices use identical serial parameters. Try a lower baud rate (2400 or 1200).
|-
| Modem not responding || Wrong cable || Requires a '''DB9F-to-DB25M''' modem cable (CB102322). The serial interface uses a DE-9 connector.
|-
| Interface drains batteries rapidly || Normal behaviour || '''Use the AC adapter''' whenever the serial interface is attached.
|}