This is very cool! Glad to see you got it working... On Sat, Mar 4, 2023 at 9:06 PM Chris Zach via cctalk <cctalk@classiccmp.org> wrote:
> Ok, after banging my head against the wall for awhile this evening it > looks like I have two flashfloppy drives working on my Pro/380. Well > enough to boot from and install 3.2 options. > > The keys are these: > 1) Use a flat 34 pin ribbon cable with three plugs in a straight line. I > tried using one with the traditional flip, got frustrated at the extra > complexity, and reterminated it as straight through all the way. > > 2) Set one drive to unit 0 (J2 installed) and the second to unit 1 (J3 > installed) > Yea, that's how the two floppy setups on the DEC Rainbow were done. Flipped cables only were a IBM-PC thing at first, though others started using them later to emulate the PC... The few CP/M machines I've played with were more like the Rainbow than the IBM-PC, but there were so many CP/M machines I might have missed it... > 3) This is the kicker: RX50's are Shugart drives. You have to go into > the configuration and set the drives to Shugart. IBMPC doesn't work > properly with the disk ready and disk swap signal, I stumbled on this > when I found that flipping the disk image while it was seeking produced > a brief access. Hah. > Yes. Pin 34 is READY, not CHANGE, and it has to come ready for the controller to like the drive. I managed to get the GoTek working with this config, but I did this for a single drive on my Rainbow. Since I have the MFM emulator, I've only dabbled with the GoTek. > 4) I set the ff.cfg also to read only to avoid stepping on the images by > accident. > > So far it seems to be working, saw both drives in the file manager (I > had built a minimum system with the floppies I had) and now I'm > reformatting the RD53 drive and doing a full install. Should be as > simple as turning the knob and hitting resume. > Nice! > Thanks to Bjoren for letting me know it kind of worked for him years ago > which gave me the knowledge that it could work. One issue I can see is > that since both "drives" use the same head, stupid software could assume > that since drive 0 was seeked to track 30 then drive 1 should be at > track 30 and thus no need to change tracks. So far I haven't seen this > happen, but we shall see. > I've not seen this assumption in practice. Part of the reason is that, I was told years ago, was because many DEC Engineers had two separate drives instead of the RX-50 in their systems, so errors like this would be caught and fixed. I never encountered any when I ran my DEC Rainbow with two TEAC FD-55F drives in either MS-DOS or CP/M. That doesn't mean they don't exist, but it's been more of hypothetical than a common thing. I'd love to see if you stumbled over this... Warner
