What speed modifications can I make to a PCjr?
There are several things that you can do to speed up a PCjr. The first improvement that you can make is to add memory via a sidecar, and use software to reserve the first 128KB of memory for DOS, a ram disk, and the video graphics memory. This forces your programs to run above the 128KB mark, which makes them faster because the access to this memory is faster. See the section on ” The Memory Subsystem ” for the details on why this is so. The second thing that you can do is to replace the Intel 8088 microprocessor with the NEC V20 microprocessor. The NEC V20 was an Intel 8088 clone that ran a little faster. Some software was not compatible with the NEC V20, most of it being games. (Broderbund’s Lode Runner is one of them.) The NEC V20 can give you a noticeable improvement; some users have reported their PCjrs running almost 15% faster. (Obviously it depends on the benchmark.) It’s going to be a little hard finding a NEC V20 now though .. at least you don’t have to worry about voiding yo
