Viewing Issue Advanced Details
|ID||Category [?]||Severity [?]||Reproducibility||Date Submitted||Last Update|
|07141||Speed||Minor||Always||Nov 3, 2018, 18:07||Nov 3, 2018, 20:18|
|Status [?]||Direction Needed||Driver||vtech2.cpp|
|Version||0.203||Fixed in Version||Build|
|Summary||07141: laser500: speed is faster than real machine|
Speed is faster than the real machine. As I've developed my own laser 500 emulator I can tell what's wrong and how to fix it:
1) The actual clock speed is slightly less than the one printed on the specs. I do not have the instrumentation to measure it precisely, but I've run several test programs on the real hardware and I found it to be ~3,672,000 Hz (and not 3,694,700).
2) Need to emulate the wait states the video chip puts on the CPU. This is rather simple, it is needed to insert ONE additional Z80 t-state for every memory access (read or write) or I/O port access (read or write).
With these simple two fixes, the speed will match the real machine.
|Steps To Reproduce|
|Affected Sets / Systems||laser500|
|There are no relationship linked to this issue.|
|There are no notes attached to this issue.|