S-100 Bus

<If you're an S-100 user, particularly if you have experience in bringing = <up a system from totally dead to totally alive, I'd certainly like to = <see what your impression of your needs from such a device might be. I've brought up several IMSAIs, Altairs, NS*, Netronics explorer 8085, several mongruls and my multi-CPU s100 crate. Front pannel systems were rich enough to accomplish the task one the FP was known working or nearly so. Often the problems were dirty switches, broken wires, failed oneshots or maybe a bad LED. Other problems were the older boards that didn't like Bus pins 20 and 70 (protect/unprotect). Must haves: ability to display memory ability to write to memory Start, stop and single step the CPU Most front pannel systems (alatir, Imsai, Ithica intersystems, PDA-80 have the basic resources. A scope may be needed if there are timing issues or one shots that are drifted off. The non front pannel systems required a FP that could be plugged in. the easiest way was a a minimal CPU (Computime SBC880) that can drive the bus but is otherwise self contained. That and a terminal is as good as a front pannel (better). The multi-cpu system needed more as the CPUs were not commercial units IE: they never worked before so they had to be debugged first and that required a bus logic analyser (capture bus state 1024 cycles deep) that could trigger on specified conditions. This was needed to look at the interaction of the many cpus and DMA devices. Once the system could run code predictably (could still crash but reset to rom monitor was reliable) The bus analyser was almost by un-needed. A simple logic proble was the single common tool besides a frontpannel or its analogue. A multi trace scope was handy for altairs (too dam many oneshots!) and other system where the problem was logic that was damaged Allison