> The few docs I have found on this (501-1910) card call it a "Bi-Pro"
> for SPARCprinter.  Shall I assume that's technobabble for "special
> purpose printer interface for SPARCprinter"?

The 501-1910 actually has two things on it: an ordinary bpp (which is
presumably supported as well, or poorly, as any other bpp is, by the
bpp driver) and an lpvi (the SPARCprinter interface).  The latter is
what I recently got a minimal driver working for (which driver Jared
even more recently made work in a kernel that identifies itself as
1.5ZB, which I assume is -current).

> I realize these printers are, ahem, "unique" in their interface
> characteristics (I assume they are little more than a marking
> engine?).

Yes, the SPARCprinter itself is little but the print engine.  The host
interface is little more than a DMA engine and SBus interface.  There
are a few registers that must be on the host card because they have to
work even if the cable is disconnected; probably all the registers the
host sees are there.  I don't know, actually, how the rest is split
between host card and printer, and I don't really see that it makes
much difference unless you propose to connect a SPARCprinter to
something other than an lpvi, or vice versa....

> Anything else I should consider before hunting around for one (I see
> them periodically at surplus for a few bucks...)?   Or, am I better
> served to stick with more "mainstream" printers?

My impression is that coming by the printer and card are comparatively
easy; the hard part is the cable between the two.  The connector on the
host end is different from everything else I know of; I suspect it may
be harder to find in isolation than the whole cable - but if you want,
I can take an ohmmeter to my SPARCprinter cable and describe the
pinout.  (The DC pinout, at least - that won't tell me which wires are
twisted together, or are co-ax, or whatever is inside the jacket.  But
if you're making your own cable, make it as short as you can get away
with and such issues are less likely to matter.  My cable's connectors
look openable, instead of molded on, so I may be able to describe even
more details - but I haven't tried opening them yet, so....)

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