cctalk Digest, Vol 54, Issue 62

Front panels for modern day computers/microprocessors are somewhat problematic. The cache(s) maintained internally allow for local instruction execution without making references to the external memory buses, and the prefetch mechanisms internal could also indicate memory activity even if no instruction or data item were actually fetched! Status information is not as directly available, and if it were it would probably not reflect status in "real time" that is occurring at the same time of viewing on the panel. Nevertheless, memory bus activity could be monitored, and what limited status information is available could be produced. The point though is the information displayed, say on minicomputer panels, is not readily available now due to higher levels of integration on the chip itself. On the note of the CDC 6600 machines, et al., There was a peripheral processor which was used to boot the mainframe, and it had many rows of toggle switches, in groups of 18 or 36 if I remember right, which either contained the boot code or controlled the boot. The peripheral processor was a computer in its own right by any standards. Hope this helps. --Geoff