IBM 6151 Maintenance And Service Manual page 121

A7x
RT PC Modem Cable - RS-232C (10 Pin)
Additional Tests: Run the RT PC 4-Port Asynchronous
RS-232C Adapter Checkout.
Removal Procedure: See Adapter Removal in Section 4.
Repair Checkout: Run the RT PC 4-Port Asynchronous
RS-232C Adapter Checkout.
A8x
IBM AT Modem Cable - RS232C/9 Pin
Additional Tests: Run the IBM AT Serial/Parallel Adapter
Checkout.
Removal Procedure: See Adapter Removal in Section 4.
Repair Checkout: Run the IBM AT Serial/Parallel Adapter
Checkout.
Fixed-disk and Diskette Drive Cable
Additional Tests: Run the Diskette Drive Checkout.
Removal Procedure: See Adapter Removal in Section 4.
Repair Checkout: Run the Fixed-Disk Drive and Media
Checkout and the Diskette Drive Checkout.
(6/88) Problem Isolation Charts 3-0020-43