VT101 8085 CPU Fault

-----Original Message----- From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of sandy hamlet Sent: 19 January 2015 19:38 To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: VT101 8085 CPU Fault Using a scope, look at the address lines and/or data lines at power up, just after system reset. The pulses will probably vary in width but should all be the same amplitude. If you see something like stair stepping: where a pulse starts out at 5 volts and drops, for example to 3 volts and then drops to 0 volts, then you might have two devices trying to access the same line at the same time. Devices on the same line may include a ram, rom, I/O ports, etc. This could cause the processor to "hang up" and act erratic. A schematic of the board would be helpfull if you have one.