Performance Session for the PC XT/370
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
A performance session is a method that accurately times and counts instructions executing on a PC XT/370. This session requires a special timer card, the Personal Computer Performance Measurement Card (PCPMC), modified E-engine microcode. For special disk measurements a resident PC DOS program is required. The performance session software runs on the 8088 microprocessor of the PC XT and it monitors and displays performance information about the XT/370 microprocessor. With this co- processor method it is necessary to steal very little of the 370 processing to be measured. The counters and timers are latched by hardware and software control logic. Most of the special instruction counters and wait-state indicators come from the E-engine microcode. The A-engine instruction counter and most of the timers are hardware latched.