EXPANSION CARDS
As originally received, starting from the power supply, the expansion slots of this 5110 are populated as follows:
| INDEX | System Description | Notes |
| A | I/O CABLE DRIVER | Connected main processor to the external IO pins at the back of the system (disk drive, tape, or printer/plotter). |
| B | | |
| C | | |
| D | | |
| E | | Would have APL |
| F | Common and Language ROS | BASIC |
| G | Display | |
| H | BASE I/O | (includes internal tape support and keyboard IO, generally coupled with the card in slot J with some “X2” connectors) |
| (skipped i) | | The IBM manual diagram for the A1 board skips Letter “i”, probably since it could be confused with “1” |
| J | Processor (full width) | PALM: Put all Logic in Microcode |
| K | Feature ROS | Parallel I/O not installed |
| L | Executable ROS (full width) | Similar to a BIOS |
| M | 16KB/16KB | Total 32KB |
| N | | Reserved for additional RWS (Read/Write Storage), to support up to 64KB |
Per the IBM 5110 MIM 2-12 page 209, the slots should be like this:
