MiSTer FPGA Forum

Hi,

Does the PCXT core correctly implement the instruction prefetch cache of the 8088? I'm trying to determine if some behavior can be attributed to the cache not being implemented at all or being implemented incorrectly (no offense intended!) or because of instruction prefetch cache starvation, which was more prevalent on 8088 than 8086 and later Intel processors (both because of limited size of the cache and because of the width of the data bus).

Thanks very much for any information!

Cheers,

--Golden

Yes, the prefetch queue is implemented the same as the real 8088. The music playing at the end of the 8088 MPH demo relies on the prefetch queue operating correctly and the PCXT core seems to run this fine. Also the tools which identify the processor type using the prefetch queue correctly identify the core as an 8088.