If memory serves, you can't actually format a drive with the RQDXx controllers, for example taking a Maxtor XT-2190 and turning it into an RD54. The VAXStation 2000's embedded controller does have the requisite firmware.
If you mean the controller cannot format a drive without assistance from a utility program, you are correct. However, XXDP includes a utility (ZRQC?? IIRC) to format the drive. In customer mode it only knows about officially-released DEC drives*. If you ask for "extended commands" or something like that, it asks you for the normal CHS parameters and then more cryptic things like "Number of XBNs?" The controller and OS driver (remember, the Q-bus MSCP controllers are host-initiated bad block replacement, so the OS driver needs to know some gory details) handle bad block replacement and make some assumptions which you can violate with your custom format parameters. You are correct that the VAXstations have the "warm and fuzzy" format program in their console ROM. But bear in mind that VAXstation console ROMs can approach (or exceed) the total 4MB addressable memory of a PDP-11.
* Terry's Trivia Time again (maybe I should trademark that): The ZRQC formatter asks you what kind of drive you have which is straightforward except for the RD52, which asks the rather cryptic question "1 or 2 LEDs". That's because of the RD52 saga, which I was involved with to a great extent. The RD52 was supposed to be an Evotek ET-5540 and DEC signed a high volume OEM purchase with Evotek - in fact, they were the only customer that committed to buying more Evotek drives than my company did. The Evotek was an incredibly elegant design (the company was started by some ex-IBM engineers that worked on the 3380 and follow-on drives) that was thoroughly permeated by problems. It was a "design too far" like the DCJ11 was for DEC. The goal was to produce a stepper-motor drive with the speed of a voice coil actuator but the cost of a stepper motor actuator. Unfortunately, Evotek had no shipping product to keep them funded during the over-extended development. In no particular order, some of the problems were:
- The drive took the 5.25" form factor spec literally. It was just at the maximum allowable dimension in every possible way. In many chassis it wouldn't fit at all. In most of the others, you had to remove the drive's faceplate and then put it back on once the drive was in the case.
- The drive had a dynamic spindle brake (a solenoid with a piece of cork on the end that rubbed on the spindle). The brake's default state was applied, with power-on retracting it. Unfortunately, the connector for the brake was a 2-pin .1" part right at the corner of the drive, meaning that when a customer installed the drive, there was a pretty good chance of dislodging the connector. That meant that instead of spinning up when powered on, the customer was greeted with the smell and smoke of the spindle motor hybrid sacrificing itself.
- The drive suffered from jitter at the end of seeks. A workaround was to delay I/O for several ms after a seek if the operation was a write, to prevent off-track writes, and to retry without reporting an error if the operation was a read, both to give the heads time to settle down. The solution to this was to "stiffen" the head carriage assembly. That is an excellent idea, unfortunately the implementation was a disaster. The solution was to place a 4-prong plastic clip on the external post of the stepper motor, with a spring squeezing those prongs against the stepper motor shaft to increase drag. This had the side effect of making it much harder to drive the stepper motor. The hybrid that drove the stepper was from the same manufacturer (has a "T" and an "X" in the name and was a specialist in mixed-signal hybrids, but this problem wasn't their fault) as the spindle motor hybrid. The stepper hybrid worked a lot harder because it had to produce continuously changing outputs. The incoming inspection failure ratio was around 50% and the on-board failure rate brought that up to around 90% once the seek stiffener clip was added.
- The heads would be dislodged when the drive was shipped, causing media and head damage. The solution to that was to place a T-shaped piece of plastic (bright red, with "Remove before use" illegibly molded into the plastic) with a rubber pad on the back that pressed against the stepper motor. We called these the "magic mushrooms". They solved the immediate problem, but customers often forgot to remove the magic mushroom before installing the drive, causing the stepper hybrid to burn out.
This nonsense went on for the better part of a year, despite my efforts (and presumably DEC's) to straighten things out. We got so sick of them sending us dud pre-production units that it got to the point that I had to fly out to Fremont and test / inspect each drive before bringing it back with me on the return flight.
Eventually their investors told them to ship drives in any condition (similar to CMI hard drives in the IBM PC) or the plug would be pulled. Specifically, "No more redesigns!". I was out there when that edict came down. I asked one of the designers why they chose these expensive, unreliable (in this application) hybrids and Tom said it was because they'd used them at IBM. Of course, IBM has whole teams intended to make designs manufacturable and repairable, which Evotek didn't. I said "Why not use sets of Darlington drivers?" and you could practically see the light bulb over his head light up. We midnight-engineered (literally) a new PCB with a 6821 (IIRC) and 3 dual Darlington arrays (which collectively took up less PCB space than the hybrid they replaced) that also moved the spindle brake solenoid connector to a more protected location. I took advantage of the space savings to add some other goodies, like making the activity LED dual-color so it would be obvious if it was blinking a fault pattern or just indicating activity. We got some drives that were close to the original specification (they missed a little bit on the seek time because of the stabilizer clip) and still had the problem of needing to ship with the "magic mushroom", but were otherwise very good drives. But by then it was too little, too late and Evotek was closed down and the sputtered media part of the company was sold to someone else.
This left DEC scrambling for a 40GB drive because in the OEM game of musical chairs, if you're late to the party you're often left standing without drives. DEC signed a last-minute deal with Quantum for their Q540 drive to be used as the RD52, but Quantum didn't have enough spare production capacity to fill those orders. So DEC bit the bullet and signed another deal with Atasi for their 3046 drive. It had a bit more capacity (hidden when formatted as an RD52) and was a
lot more expensive. As far as I know, it was also the only ST506-interface drive to ever use a
linear voice coil for the head actuator (rotary voice coils eventually took over from stepper motors).
The Quantum Q540 has a single LED. The Atasi 3046 has 2. That's why the DEC format utility asks.