Slowdown in Victory Road

[MaximRecoil]

This PCB seems to run somewhat slow, particularly the firing of the big flame type weapon that you start out with. Everything seems sluggish though, and it never does seem to run at 100% speed. I know that some games had inadequate hardware and slowdown was a byproduct of that -- Double Dragon comes to mind -- but I didn't think this was a problem with Victory Road, and it doesn't happen in MAME either for this title.

So what could cause something like this? My first thought would be the CPU(s), but the game would not even run if it had incorrect or malfunctioning CPU(s) would it? Everything seems normal with the game other than the slowdown. It has two speeds, slow and slower, and never seems to go full speed regardless of what is going on in the game.


There are three Z80's on the top board which all have this printed on them:

Zilog
Z8400APS
Z80 CPU
8622

This doesn't appear to be a bootleg of any sort. The cabinet is dedicated and unhacked. (Dynamo HS-1) with original sideart, bezel, marquee and CPO. It also has the original operator's manual and some other paperwork from SNK and Wells-Gardner. The following is screened on the board:


A6002UP03-02
Made in Japan
SNK Electronics


Maybe someone who understands this old hardware better than I do has an idea of what could cause the game to not run at full speed but otherwise run flawlessly?

[grantspain]

sounds like one or more of those z80's are breaking down

[SirPeale]

I remember this happening in the arcade when I was a kid.

[MaximRecoil]

I remember this happening in the arcade when I was a kid.

I never played it in the arcade so I couldn't say. I did play Ikari Warriors though and it never ran slow.

If it is normal for it to run slow on the real hardware, then why doesn't it run slow in Mame? Double Dragon shows the same slowdown in Mame as it does on the real hardware.

[SirPeale]

If it is normal for it to run slow on the real hardware, then why doesn't it run slow in Mame?

Because Mame is full of bugs and hacks?

Because despite best intentions, Mame does *not* have accurate emulation for a huge number of games?

Don't get me wrong...I *love* Mame.  But asking this question is like asking why Coke and Diet Coke taste different.  Sure they're *similar*, but they're still miles apart.

[MaximRecoil]

If it is normal for it to run slow on the real hardware, then why doesn't it run slow in Mame?

Because Mame is full of bugs and hacks?

Because despite best intentions, Mame does *not* have accurate emulation for a huge number of games?

Don't get me wrong...I *love* Mame.  But asking this question is like asking why Coke and Diet Coke taste different.  Sure they're *similar*, but they're still miles apart.

It doesn't seem right to me. Victory Road is not really any more graphically intense than Ikari Warriors is, and pretty much the same hardware is being used.

I wish I had another Victory Road PCB to compare it to.

Other than Robotron (which only shows speed differences later in the game), are there any other examples of games that run normal speed in MAME but are in a constant state of slowdown on the real hardware?