Falcon floppy problems

[exxos]

I'm slightly confused now as you said ..

The track between pin 16 of the CPU and the VIA is damaged

Now you say...

Currently Pin 16 of the 030 isn't connected to anything and pin 17 which is also lifted is connected to the Afterburners wiring loom.

So has pin 16 been deliberately lifted, or a broken via ?

I don't know how AB fits, so you probably best looking at the install manual as to what is done to the falcon and whats not. I know some pins on the CPU were lifted on the CPU for some reason, maybe tied to a power rail to disable the CPU most likely, but pins should never by left floating.

Though I would suggest if the DMA has been overclocked, along with any chips, you start putting stuff back towards a stock machine.

[Acsi]

Sorry it should have read the track between pad16 and the via next to it appears to be damaged.

Actually now that I have the Afterburner out of the way I can see that it's actually pad17 where the track is damaged not pad16.

Pin17 has been connected to ground and pin16 is floating. Hopefully I can reconnect pin16 to pad16 and use the wire from pin17 to connect it to somewhere and bypass the broken track.

Wish me luck.

[Acsi]

OK I expected this but wished for better.

After removing U65 and U37 and putting in a new 32MHz oscillator at U37.
Then patching the broken traces and reconnecting as best I can tell pin 16 of the 030 and hooking pin 17 of the 030 up to pin3 of the expansion port to bypass the broken track.
Installing a clock patch.

I get a black screen but at least get a signal to the screen.

OK 030 is getting hot quick so I must have a short somewhere

[Acsi]

Mad scientist moment... "IT'S ALIVE!!!!" cue evil laughter.

Now to see what happens with the test cart and a floppy drive

[Acsi]

OK so here's what I've got

RAM good
ROM good
Keyboard good
Mouse good
Blitter good
Timing good
IDE Seems good but won't boot (CF may not be set up as I can't remember the state I left it in)
Video good

Floppy same as before does not spin and LED on drive stays on. LED on keyboard behaves correctly when trying to access the drive.
When tested it says the disk is either write protected, Time out waiting for Index or Time out waiting for Interrupt depending on the test tried.

So what's the chance the fault is actually with the Ajax chip?

[exxos]

I really would try my first suggestions on all this. https://www.exxosforum.co.uk/forum/viewt ... 700#p37508

and my second in removing that SDMA resistor.

[Acsi]

The SDMA resistor is gone along with the wire as it was part of the AB installation instructions I backed it out to get the machine back to as stock as possible,

I’ll look tomorrow to see if I have one of those resistor packs.

Quick question though can the WD1772 (16MHz capable) be used in place of the Ajax in the Falcon?

[exxos]

Quick question though can the WD1772 (16MHz capable) be used in place of the Ajax in the Falcon?

I don't know how the falcon drives the 1772.. Likely its "stuck" in 16MHz all the time. So they may work for about half a hour before they start overheating. My floppy kits always switch back to 8MHz when not in use, so theres no problem then.

[Acsi]

I only have a 4.7k resister array. Would that be OK to try on it?

I have ordered a new Ajax chip but God only knows how long that'll take to get here given everything that's going on. Covid wise it's probably a good thing if it does take awhile.

[exxos]

Is that for the DMA fix ? I've not looked into it on the falcon, but a SIL on the 1772 data bus can't hurt anyway. 4.7k should be fine anyway.

You also need resistors on the IIRC LS06 inverter which is in between the 1772 and floppy. That was the main reason for write protect errors.