Ethan Dicks wrote:
On 6/20/07, Dave McGuire <mcguire at
neurotica.com> wrote:
On Jun 20, 2007, at 3:48 AM, Sridhar Ayengar
wrote:
The 11/[750,780,785,790,795] has Massbus too.
Well they *can*. As can many PDP-11s. So yes, I suppose you have
a point!
I haven't tried to find an RH-11 recently, but an RH750 is a single
card (no backplane required), with a simple cable arrangement from the
11/750 backplane to the I/O bulkhead area (theoretically, depending on
how a modern Massbus device was constructed, one could even just run a
trio of 40-pin cables between the 11/750 backplane and the new device,
and bypass "real" Massbus cables).
The plan is (because real massbus
connectors are so hard to find) to use
3 40 pin ribbon cables (aka the in-cabinet massbus cabling) to go
between the controller (RH11, RH70, RH750, RH780, etc) and what I'm
building. That still allows for using an external massbus cable
arrangement if one so desires.
I don't have hard numbers in front of me, but am of the opinion that
there are enough hobbyists who would buy a new Massbus disk to make
the effort worthwhile. Of couse there are more who could use a Unibus
disk, but that's no reason not to take a stab at Massbus.
I hope so because
this is going to be a lot of work. :-) Not only do I
have to do the hardware design (and fab) but also have to write the
verilog for the FPGA and a resonable amount of code on the uC.
I'm in the process of redesigning my website. As part of that I'll put
up more details on "legacy disk emulator".
--
TTFN - Guy