Zane H. Healy wrote:
On Thu, 6 Aug
2009, Chuck Guzis wrote:
On 6 Aug
2009 at 3:59, Philipp Hachtmann wrote:
what do you think about a Unibus to PCI bridge?
I think such a device - if well done - could be real fun. There has
been a commercial approach somewhere - but it doesn't seem to be
available anymore.
Are you sure that you're not thinking of the Osprey ISA QBus/UniBus
adapters from Strobe Data?
http://www.strobedata.com/home/products.html
There are/were PCI adapters as well. Someone like John Wilson would have
details on them.
I suggest that the first thing you decide when you use a Unibus <=> PCI
bridge is which CPU will be used to run the code. If you are running
native x86 code, then the choice is fairly obvious since I don't seem to
ever have seen an x86 emulator written for a Unibus based system.
On the other hand, if you are executing PDP-11 code and you are a
commercial user (not very likely on this list I admit), then John Wilson
sells the license for about the same price for Ersatz-11 as the bridge
hardware. The current problem is that the company that used to
build the bridge hardware stopped making the bridge a number of
years ago, if I remember correctly.
The real question is why you want to make use of the bridge hardware.
About the only reason is that you have VERY unique Unibus hardware
that is not emulated by Ersatz-11. Can you specify what that hardware
does? That hardware might be easier to emulate than you think.
If the question is rhetorical, then until there is a specific need, the
cost of
development of new hardware is probably not worth while.
Sincerely yours,
Jerome Fine
