84PCE:Ports:5000
From WikiTI
| Port | Default | Bits | Information |
| 5000 | 00 | ?? | May or may not serve a purpose? |
| 5001 | 80 | ?? | Bit 2 is set while any key is being pressed |
| 5002 | 00 | ?? | Ports 5002-5003 may always read zero |
| 5004 | 11 | FF | Reset bit 4 to freeze |
| 5005 | 30 | FF | Setting bit 2 or bit 7 (or both) will freeze the calculator |
| 5006 | 00 | 3F | Latches value written |
| 5007 | 00 | Ports 5007-500B may always read zero | |
| 500C | 19 | FF | Reset bit 4 to freeze |
| 500D | 00 | FF | Latches value written |
| 500E | 00 | 3F | Latches value written |
| 500F | 00 | Port 500F may always read zero |
