george@wombat.bungi.COM (George Scolaro) (10/06/90)
Hi folks, to maintain my boredom threshold at a reasonable level while Dave fiddles with some neat software - I decided (after some pressure from Dave) to build a mips-ometer for the pc532. The 32532 has a pin called /PFS which is unused on the pc532. The 32532 pulses the /PFS pin for every instruction which it executes - a maximum of 12.5 million times per second at 25 MHz running nops etc in the cache. So, by using the spare near the 32532/32381 I soldered a 74HCT4040 to divide the /PFS by 4096, then ran some wires across to unused pins of Serial Channel 8. Plugged in a cable to run to a wirewrap board with an 87C51 microcontroller and an 8 character smart LCD panel. Eventually I will mount it through one of the dummy 1/2 height panels on the tower case. Dave then wrote some software to count pulses and update the LCD panel every second. So we now have an accurate MIPs display for our pc532 - EL backlit no less! Nops in the cache run at 12.5 MIPs, sieve runs at about 7.5 MIPs and GNU C around 3 MIPs. The next step is to write more software so that we can use the serial channel on the 87C51 to communicate with the pc532 - then we can display info like mail waiting etc etc. Now that we have an 87C51 at 12MHz (i.e. 1 MIPs) maybe the we can call it multi-processing... Anyhow, its pretty neat to see the activity change as Minix ticks along - while in the idle loop waiting, the 532 is doing around 30KIPs. If anyone is mad enough to want to replicate this - I could generate a netlist for building the board - and Dave could post the software. best regards, -- George Scolaro george@wombat.bungi.com [37 20 51 N / 122 03 07 W]