exxos's Atari, Amiga & retro forum

Icky wrote: 07 Oct 2018 22:50 Yep - just measured 1K

What may confuse about DRQ on the DMA having a pull up on the original (the 1K is on the input).. Is the output doesn't have pull up, BUT, that is because original ST used open collector to the DMA pin (LS06).. I used a LS04 which doesn't need pull up. This buffer only drives DMA input, so I saw no problem with that...But maybe something doesn't like that, as even on STE uses LS06... odd...

Might be worth checking I wired the DMA port up right though ;)

exxos wrote: 07 Oct 2018 22:54 Might be worth checking I wired the DMA port up right though ;)

I did wonder that :) - so far it looks ok. Am still checking.

Icky wrote: 07 Oct 2018 22:57 I did wonder that :) - so far it looks ok. Am still checking.

I guess you could swap the LS04 (U51) for a LS06 and add pullups.. its only used for midi so far (and now unused HSYNC buffers)..

I checked on a lot of schematics and all use open collector.. don't see why, but I guess must have been a reason for it.,, :shrug:

exxos wrote: 07 Oct 2018 23:04

Icky wrote: 07 Oct 2018 22:57 I did wonder that :) - so far it looks ok. Am still checking.

I guess you could swap the LS04 (U51) for a LS06 and add pullups.. its only used for midi so far (and now unused HSYNC buffers)..

I checked on a lot of schematics and all use open collector.. don't see why, but I guess must have been a reason for it.,, :shrug:

Finished checking connector - it is wired correctly.

Just been trying to find a LS06 looks like I am out of them.

Icky wrote: 07 Oct 2018 23:19 Just been trying to find a LS06 looks like I am out of them.

I can send you one, probably won't be for a couple of days though..

exxos wrote: 08 Oct 2018 11:14 I can send you one, probably won't be for a couple of days though..

Thanks for the offer but I ordered some last night as I needed to restock on a few components.

Icky wrote: 06 Oct 2018 22:30 I can confirm that we do indeed need a floppy connector board just like the monitor connector one.

Will get on that today! thanks.

I'm confused..


is this image correct ?


Because...

So pin 1 is read_data, which matches your "fixed" image...

Oh nevermind...


It looked right (and actually is) but the pins on the connector are not matching the pin labels on the pins :roll: Man I really hate eagles lib editor :roll:

Is there a typo on pin 5, as on the ST sch pin 5 is drive_0..