Track / Density Display for 1050

[macsonny]

Hi All,

 

I always really liked the feature on the Indus GT drives that showed track number. I’ve been doing some reasearch and found this site that shows hot to build up a LED display for connection to a Speedy 1050.  https://blog-3b2-sk.translate.goog/igi/post/Atari-Speedy-1050-part-13-Track-display.aspx?_x_tr_sch=http&_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp

 

I was wondering if anyone knows of a solution to have a LED display from the 1050 that would show both density and track number?

 

Thanks

 

Sonny

[TGB1718]

Track number would be relatively easy using a micro controller to count the step/direction/track 0 pulses

and output to a 7 segment display, as for density, can't help there sorry.

[xrbrevin]

i tried it a while ago but despite making some good progress, i ended up with a drive problem. i assumed it failed due to my experiment but i got the drive running fine again later. i havent resumed the experiment tho, im a bit wary of taking another risk

 

 

[Rybags]

One of the RIOT data registers contains the bit controlling density.

From a quick look at the (reverse-engineered) source code, the bitsetting controls what density the drive will attempt to read/write.

When a disk is inserted the drive will attempt to read an index pulse in enhanced, then single if that doesn't work.

After that, status flags are updated (likely just Ram based only)

Sampling the PORTA output bit 5 might be sufficient - likely it would indicate single if an unformatted or unreadable disk was present.

Edited March 19, 2022 by Rybags

[_The Doctor__]

consider currents and limiting anything you add on as well, that way you don't kill the drive...

[macsonny]

14 hours ago, xrbrevin said:

i tried it a while ago but despite making some good progress, i ended up with a drive problem. i assumed it failed due to my experiment but i got the drive running fine again later. i havent resumed the experiment tho, im a bit wary of taking another risk

 

 

I really liked where you went with this. Just wondering what the final design was and what you would do different if you were to try again?

[macsonny]

So I started to build up a system that will display density, protection, drive ID and sector number. Here's a little demo.

 

I'm suing a micro.bit which I think is just an Arundino. I'm using a 128 x 64 pixel display. I've already built the logic for the drive ID using 3 of the inputs. I've built the protection logic using 2 of the logic inputs. I think I can get the density setting for J4 using 3 more logic inputs.

 

Note the screen doesn't flash - just the capture rate of my iPhone. Excuse the misspelling on the demo too.

 

Now I just have to work out how to extract the sector number from the drive. I suspect I'll need that from the WD IC. Any tips?

[Rybags]

Since you're going to so much trouble, why not modify the drive firmware to help out?

 

Sector # - I'm fairly sure there that the floppy controller never deals in sector numbers as Atari calls them - instead you have track and sector # within the track.

But if you're snooping the bus and certain other port bits you'd probably be able to deduce it (density would come into play there as well)

[xrbrevin]

for track number, the FDC has pins for step, direction and zero. my intention was to use arduino code to interpret these to drive a 2x seven segment display

however the RIOT chip drives the stepper motor forward and back so these could be used but the code would have to be diff'rent