per
Veteran Member
I have recently gotten a 4MHz Z80 computer (a Tiki-100) that has certain problems. The CPU seems to start and access the floppy drive just as during a normal boot, but the video output gives no response whatsoever. This system uses video hardware made from the ground up entirely by TTL, so it should technically not be too great a problem fixing the issue. If I had the right tools.
My multimeter obviously does not hold up to the task. I need some kind of logic probe, that can be used to verify if a signal reaches its destination or not. The probe must have several inputs, and must be able to trigger and record for some time when a given change occurs. The reading and displaying of video RAM seems to work, so the problem is problably somewhere in the interface between the CPU and video hardware. There is quite a bit going on there, especially lots of multiplexing and waitstate shenanigans.
Is my best bet some custom code on an Arduino, or a comercially available logic probe? Price is a major factor at the moment.
My multimeter obviously does not hold up to the task. I need some kind of logic probe, that can be used to verify if a signal reaches its destination or not. The probe must have several inputs, and must be able to trigger and record for some time when a given change occurs. The reading and displaying of video RAM seems to work, so the problem is problably somewhere in the interface between the CPU and video hardware. There is quite a bit going on there, especially lots of multiplexing and waitstate shenanigans.
Is my best bet some custom code on an Arduino, or a comercially available logic probe? Price is a major factor at the moment.