520ST with 16MHz Booster low benchmark

[Astal]

Hello! I just installed a 16MHz booster in my 520ST, for some reason it's benchmarking EXTREMELY low, 46% for display, 99% for CPU, which strikes me as odd for a 16MHz booster. Board is a C070115 Rev 2B. Haven't applied fixes but it just seems quite odd to be so slow.

Although looking at the reference for 6.31 it's an STE with BliTTER under TOS 2.06, would the CPU be a 16MHz on that one as well?

[stephen_usher]

Sounds like noise on the ground causing the CPU to miss clock cycles. I had a similar problem with one of my CPU relocator boards.

[Astal]

What would a good way to fix this be?

[stephen_usher]

Check how good the connections are for a start.

[Astal]

Dumb issue... Just checked the frequency on the CLK pin, 8MHz, it's in 8MHz mode... I'll throw it in 16 and look again :P

[Badwolf]

Although looking at the reference for 6.31 it's an STE with BliTTER under TOS 2.06, would the CPU be a 16MHz on that one as well?

Change the reference to the 8 MHz STFM before you get the spanner out -- rule out the simple.

The blitter does a lot of heavy lifting in the GB6 tests, so 46% doesn't sound unreasonable STFM v STE. Make sure same resolution too.

The 99% CPU sounds a bigger issue, but double check that reference before panicking.

Edit: seen your subsequent reply.

BW

[Astal]

@Badwolf It looks like it is all hooked up properly is the weird thing, jumper is not bridged and the 16MHz input has 16MHz on it. Do I need to tie SEL high to get 16MHz?

Edit: Do not do that, it will cause issues, well I can't figure out how to get this thing going at 16MHz... If anyone has ideas please let me know.

[exxos]

I assume you read the install guide ? 16mhz on is default. Sounds like you not connected the 16mhz wire and maybe not installed the fast ROM board ? Would help if you post some images of your install.

https://exxosforum.co.uk/forum/viewtopi ... 104&t=3825

Also as mentioned,you seem to be trying to compare a STE with blitter to a ST without blitter. You need to select the proper benchmark file. Files are listed in the readme of GB6.

Also I don't know when you got the board, but some early ones were ROM decoding only and did not have all the booster logic and were sold cheaper. So depends what you got exactly as well. It should be marked with marker pen on the PCB if ROM only.

[Astal]

Marker on the PCB for ROM only, that'd be it. The actual ROM section won't fit on this ST so I guess I've just got a super tall 68000 :P

I read the install docs and was confused because of that, is there a way to put the rest of the booster logic on it? It looks fully populated so I'm guessing it's something with the CPLD?

Edit: just looked at the receipt, I paid the full 25 GBP but it's decoder only?

[exxos]

I read the install docs and was confused because of that, is there a way to put the rest of the booster logic on it? It looks fully populated so I'm guessing it's something with the CPLD?

Afraid not so simple. They were earlier runs mostly and the design changed a few times across batches. Even so, you would would need a atmel programmer and they are hard to find and expensive. If i gave away the firmware everyone would just be buying the cheaper rom board and flashing it with the full firmware anyway. You purchased the cheaper ROM decoding only board. If you want the booster board then you have to buy the proper booster I'm afraid.