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Performance Session for the PC XT/370

IP.com Disclosure Number: IPCOM000062048D
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 13K

Publishing Venue

IBM

Related People

Erhard, JJ: AUTHOR [+4]

Abstract

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.

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Performance Session for the PC XT/370

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. The performance session screen consists of 24 fields; each field displays the contents of a counter, timer or calculation. The performance session software calculates percentages and time differences using the hardware and software counters and timers. The following measurements are taken and are listed on the performance session screen. They are updated whenever an attention key is entered into the performance session, and they may be cleared at any time with a PF key. The total job time is given in microseconds. This is the total time that a task runs, and it does not include idle wait time. It requires a microcode set hardware latch (non-I/O wait) and software calculation. The number of 370 instructions is a count of all the 370 instructions executed on the three microprocessors of the XT/370 processor card. This field is the sum of a hardware-latched counter for the A-engine and floating point- engine instructions, and several microcode counters for the E-engine instructions. The I/O wait time is given in microseconds. This is the total time that a task...