1 Mar
2008
1 Mar
'08
9:58 a.m.
der Mouse wrote:
Well if my SBC6120 ( PDP 8 Clone) can have a IDE interface
why not some other PDP. We are not looking for high speed
just hardware in this case.
> Some time
back (years), someone was working on an IDE interface for
> a Qbus MicroVAX and I was doing the driver. [...]
> We never got it working, and it is not clear
to me, now, why not.
> [...] what memory I have indicates that there were hardware issues,
the likely reason is PDP-11 and VAX does read
before write and IDE
does not like that.
Huh? The only sense I can think of in which the PDP-1 and VAX could be
said to do read before write is in the bus transaction sense, and
anything that could be called "IDE" was insulated from bus
transactions. While the card didn't have much smarts, it did have that
much; it looked enough like a wdc that I did the driver as an "attach
wdc at uba with wdc_uba" attachment layer, rather than a completely new
driver. I find I still have my copy of the dev directory, including a
boot-time console log: