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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
08542 Timing Minor Always Jan 1, 2023, 22:09 Jun 21, 2023, 13:52
Tester StHiryu View Status Public Platform MAME (Official Binary)
Assigned To Resolution No change required OS Windows Vista/7/8 (64-bit)
Status [?] Closed Driver
Version 0.251 Fixed in Version Build 64-bit
Fixed in Git Commit Github Pull Request #
Summary 08542: spec128, specpl3e: Some spectrum models are running at wrong speed
Description Some spectrum models (Zx Spectrum 128 and Zx Spectrum +3) are running a little bit faster (50.021154 Hz) than they should, according to this link:

https://worldofspectrum.org/faq/reference/128kreference.htm

"Note that this means that there are 70908 T states per frame, and the '50 Hz' interrupt occurs at 50.01 Hz, as compared with 50.08 Hz on the 48K machine."
Steps To Reproduce Launch one of those spectrum models:
-spec128
-specpl3e
Additional Information
Github Commit
Flags
Regression Version 0.244
Affected Sets / Systems spec128, specpl3e
Attached Files
 
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Notes
7
User avatar
No.21570
holub
Tester
Jun 19, 2023, 14:55
edited on: Jun 19, 2023, 16:34
I'm not sure how to match this numbers because 3546900/70908 gives you 50.02, not 50.01
User avatar
No.21571
holub
Tester
Jun 19, 2023, 16:34
We discussed this with folks on Spectrum channal and came to conclusion WOS has a typo here.
User avatar
No.21572
StHiryu
Tester
Jun 20, 2023, 01:08
So 50.02 is the correct value?
User avatar
No.21573
holub
Tester
Jun 20, 2023, 05:50
50.021154 - yes
User avatar
No.21574
StHiryu
Tester
Jun 20, 2023, 08:10
Cool, thanks for watching at this.
User avatar
No.21575
Robbbert
Senior Tester
Jun 21, 2023, 05:35
So, does this mean there's no issue and it can be closed?
User avatar
No.21576
holub
Tester
Jun 21, 2023, 08:27
Can be closed. Mame's value is precise