DEC Pro hard drive formatter

Chris Zach cz at
Thu Jan 14 12:42:11 CST 2021

Hm. I did not know this, although the RMD process does show SY1: as well 
as SY0: so it makes sense.

I'll have to try that. The power supply in the Pro is somewhat limited, 
wonder if you set the drives up to power up in sequence if it would hold.

Longer term Pro project for me is to figure out if/how to get I/D 
support in P/OS. I don't know if 3.2 supports split I/D and right now 
the thought of making 30+ floppies is making my head hurt.

Is there a hardware emulator that can emulate RX50's from images to a 
Pro? Been wondering that...


On 1/14/2021 1:28 PM, Paul Koning wrote:
> I'll give that a try, thanks Chris.
> The hardware supports multiple drives just fine (one per controller).  The power supply shuts down with three hard drives, though, the surge current is too high.  I could work around that if I ever needed two.  Two drives is not a problem, and my RSTS code supports this.
> 	paul
>> On Jan 14, 2021, at 1:25 PM, Chris Zach via cctalk <cctalk at> wrote:
>> Hm. I remember that POS 2.0 and above would just format the hard disk and go during the install. Likewise I don't know if you can have multiple hard disks in P/OS so that's a pain in the tail.
>> Boot from floppies and just init the raw disk.
>> C
>> On 1/14/2021 11:39 AM, Paul Koning via cctalk wrote:
>>> I'm wondering how to do hard drive formatting, which is likely to be needed when working with emulated disks in David Gesswein's MFM emulator.
>>> As far as I can tell, RT-11 can do this.  At least I have a source code printout for such a formatter.  But while I can find a hard drive image of RT V5 for Pro, I haven't found any floppy-bootable images.  And I think it's a bit tricky to create one.  I knew, long ago for V2...
>>> Any suggestions?  Any alternative sources for a formatter?  I guess I really should consider typing in the core of that formatter and adding it to RSTS.
>>> 	paul

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