DEC Pro350 fails floppy on POST

[snhirsch]

I've been picking away at this issue for a while now. I'm coming to the belief that the Pro floppy controller is testing for the expected RX50 drive by doing something like this even when no floppy is inserted:

• Select drive, home head and step inwards to track N (0 <= N < 80)
• Step out N tracks.
• If Trk0 is true at that point it assumes an operational RX50, otherwise fail the floppy subsystem.

How does FF behave when the host selects and steps in the absence of an inserted diskette? I can hear the RX50 whirring in and out during POST and I think this needs to be happening with FF as well. If that's not the current behavior, can it be modified to do so when 'host = dec' is set?

This behavior may be particular to the Pro3xx controller firmware as no such problems appear on, e.g. an RQDX3 controller (PDP-11).

[keirf]

FlashFloppy obeys step commands and asserts Trk0 as appropriate even when no image is mounted.

[snhirsch]

Hmm. Then I'm back to square one. The only workaround for now is to always have a non-system diskette inserted in the first FF drive. A real RX50 does not require that a diskette be present. I've managed to dump the controller firmware from the masked 8051 and this just provides a bit more impetus to disassemble it.

Just curious: Am I the only person to report such an issue?

[timradde]

Yes, my 350 does this too. Normally I have a usb stick in so never see this. It seems to boot fine with a stick in at least until I updated from 3.39 to 3.43 flash floppy. I have two images on my stick. Neither boot of course, but neither seemed to prevent the 350 from coming up. Now one image fails and the other succeeds in starting. Neither image can be recognized with something on them. I have the RT-11 OS on mine. A DIR just returns an error on both. Yet, one of these is an image I can boot on my Rainbow so was sure it would work here.

[snhirsch]

Interesting data point. I only ever tried non-bootable P/OS images.

[timradde]

I had really hoped that would work as it would allow me to get stuff to the Pro from the Rainbow. Still trying to figure out how to best get things (code) to the Pro. I can read floppies it seems. Thought that did not work for me. I must have mis-remembered. But I would like to use the Gotek.

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On Fri, Mar 21, 2025 at 12:05 PM Steven Hirsch ***@***.***> wrote: Interesting data point. I only ever tried non-bootable P/OS images. — Reply to this email directly, view it on GitHub <#970 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AN77PWWVWDHLEATE4XINKOT2VRBD7AVCNFSM6AAAAABYHST4Y2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDONBTHE2TOOBVGQ> . You are receiving this because you commented.Message ID: ***@***.***> [image: snhirsch]*snhirsch* left a comment (keirf/flashfloppy#970) <#970 (comment)> Interesting data point. I only ever tried non-bootable P/OS images. — Reply to this email directly, view it on GitHub <#970 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AN77PWWVWDHLEATE4XINKOT2VRBD7AVCNFSM6AAAAABYHST4Y2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDONBTHE2TOOBVGQ> . You are receiving this because you commented.Message ID: ***@***.***>