Solid State Disk replacement for RD53, 54, RK05, RL02/02

[Johnny Billquist]

"e.stiebler" <emu at e-bbes.com> wrote:

> Dave McGuire wrote:
>>> >> OTOH, they old ones show up on ebay frequently, and they are not that 
>>> >> expensive.
>> >   Not that expensive?  I call $100-200 for a Qbus card pretty pricey.  
>> > Unibus models go for many hundreds, upwards of $1000.
> 
> Sorry, but the new one want be cheaper than that. That's why I don't 
> call them expensive.

Indeed. If we talk $200 just for the board, and then you still have do 
develop the firmware, then $200 for a actual, already tested and proven 
SCSI controller is cheap.

And new SCSI disks can still be bought as well. And while not dirt cheap 
perhaps, they are still not that expensive. Especially since you are not 
interested in several hundred gig drives for a PDP-11 anyway.

Someone else asked about differences between a RQDX1 and RQDX3, from a 
software point of view. There is none, except in the irrelevant parts, 
such as the identity given by the controller, and version numbers and so 
on. The controllers are both MSCP. In fact, they are no different 
(either of them) from a KDA50, or UDA50 for that matter. Or any other 
MSCP controller. That's the whole point of MSCP.
The controller always present the same interface to the computer. What 
it does on the other side is hidden.

So, in fact, the device driver is the same for all these controllers, in 
all operating systems.

MSCP is a great concept. Just wish it had survived. But, as with many 
DEC designs - they were technically wonderful, but they weren't PC. And 
PC became the de facto standard. No matter how lousy the hardware was/is.

	Johnny