INT48FIX DOCUMENTATION Published by: PC Enterprises 2400 Belmar Blvd, Wall NJ 07719 Author: P. Joseph Calabria INT48FIX is a PCjr utility that solves several keyboard problems which can exist on a PCjr - even after the PCjr is upgraded to include a full size keyboard. When INT48FIX is executed, the PCjr's usual INT 48 routine is replaced. The new routine that provides greater PC compatibility. To understand the problem solved by INT48FIX you must first know that most other computers come with keyboards which have at least 83 keys while the PCjr came with a 62-key keyboard. Even though the PCjr's keyboard has fewer keys, the PCjr can still generate all the key codes which can be produced on an 83-key keyboard. To do this, a special BIOS routine is run whenever you press a key. This routine is called INT 48. INT 48's job is to evaluate each key that you press. If the key that you press is a normal key, the letter A for example, INT48 simply passes the key code to the PCjr's usual keyboard handling routine. However, when a key code which has a special meaning is received, INT 48 converts the key code to the code that a full size keyboard would normally send. For example, keep in mind that the PCjr's 62- key keyboard does not have a BACKSLASH key (\). In order to generate the backslash character you must first press the ALT key, then press the SLASH key. When INT 48 receives this combination of keys, it always converts the SLASH key to a BACKSLASH. In this situation all is fine if you wanted to input the backslash character, however if you actually wanted to send an ALT key, then a SLASH key the problem occurs. As a result of this translation, a PC program can never receive the ALT-SLASH combination. That's why programs such as Sidekick, which require pressing the ALT-SLASH combination will not work correctly on a PCjr. When you have a full size keyboard, your keyboard can send the same key codes the computer as any other full size keyboard. As a result, the key code translations performed by INT 48 can become an obstacle. The INT48FIX routine strips the usual INT 48 routine of key code translation routines which are no longer required when a full size keyboard is used. We recommend all PCjr users who use a full size keyboard install and use INT48FIX each time DOS is started. PCjr users who use either the chicklet or replacement style PCjr keyboard must NOT use INT48FIX as doing so removes support for keyboard translations which are needed when you use on the 62-key keyboards. PCjr owners who use the PCE Compatibility Cartridge or Game-Master sidecar, do not need and should not use INT48FIX. For more information on the PCE Compatibility Cartridge contact: PC Enterprises "The jrProducts Group" Customer Service: 1-908-280-0025 Order and Catalog Hotline: 1-800-922-PCjr The PCjr Lives. There is a Reason!