exxos's Atari, Amiga & retro forum

Memspeed is saying:

READ 30.1 17.3 17.3
WRITE 20.0 20.0 20.0

All three jumpers are set.

4Mbits , 512Kx8, 5V, 55ns : https://www.mouser.com/ProductDetail/Mi ... TBuOlXo%3d

4Mbits , 512Kx8, 5V, 45ns : https://www.mouser.com/ProductDetail/Mi ... xJG56nE%3d

Hi Steve

Interesting issue. I have not seen that personally with my Mach64 but I guess it could be me not paying attention.

One thought - I wonder if the VME fix to save 1 clock cycle per transfer would improve this?

Atarian Computing has a good guide on this http://www.atariancomputing.com/blog/tt ... keitfaster

I haven't plucked up the courage to tackle the fix on my TT yet as its a bit precious to me and I need a lot of spare time to make sure I get it right and time is a rare commodity :)

Thanks for the advice, but I think my TT already has that done. I don't know if you run Mint, but a good test is to see how fast the xaaes/teradesk desktop comes up. In 16bit colour it takes about 30 seconds for the desktop to appear, in 256 colours its instantaneous.

I'm interested in this topic too. My TT also came back with a time value of 7.290 on the Float Math, so half as fast as some of the other benchmarks posted around here. I don't have any CPU acceleration installed, and I'm not sure exactly what the tech history of this device is, but has a GE Soft Mighty Mic 32 B RAM board in it with H514400J-70 and H531000J-70 chips.

I'd love to find out how to get it to work with the faster speed FPU.

zrhbert wrote: 02 Jan 2026 16:16 I'm interested in this topic too. My TT also came back with a time value of 7.290 on the Float Math, so half as fast as some of the other benchmarks posted around here. I don't have any CPU acceleration installed, and I'm not sure exactly what the tech history of this device is, but has a GE Soft Mighty Mic 32 B RAM board in it with H514400J-70 and H531000J-70 chips.

I'd love to find out how to get it to work with the faster speed FPU.

There's a jumper next to the FPU & VME port, it sets the FPU to 16mhz or 32mhz. Changing that should fix it.