exxos's Atari, Amiga & retro forum

exxos wrote: 03 May 2020 21:31 Finally tested the PLCC MFP!

I don't know if anyone else has tried that or not, I cannot find the "tested list" @Icky ?

Icky wrote: 03 May 2020 21:44 Not tested yet @exxos and list is here https://www.exxosforum.co.uk/forum/viewt ... =78&t=2457 :)

exxos wrote: 08 Jul 2020 11:22 Been puzzling why the TF536 kept resetting on my H4 so did some quick poking out just..

For some odd reason its really sensitive to the ST's DTACK. It only works when I touch DTACK or have the scope probe on it :shrug: signal looks otherwise fine on the scope. So not sure what the issue is there. Could be some slight timing issue somewhere @terriblefire ?

terriblefire wrote: 08 Jul 2020 11:33 Possibly. The way it works is that it lets ST DTACK become DSACK1 after a resync period has passed.. By that time the 030 is in 7Mhz mode..

exxos wrote: 08 Jul 2020 11:52

terriblefire wrote: 08 Jul 2020 11:33 Possibly. The way it works is that it lets ST DTACK become DSACK1 after a resync period has passed.. By that time the 030 is in 7Mhz mode..

I don't know if the xilinx stuff can have schmitt inputs or not, if it has (and not already) turn it on for the DTACK signal ? I mean scope probe is like what, 3pf on x10 or something. So might just be picking up noise.. Or possible doesn't like the slow rising edges of DTACK ?

terriblefire wrote: 08 Jul 2020 11:54 There isnt a Schmitt trigger but i can get rid of the noise by sampling it with the 100Mhz clock... will just delay dtack by 10ns...

terriblefire wrote: 08 Jul 2020 11:54 I can try that if you have the means to reprogram it?