The difference between dz and dh interfaces is that the dh used dma instead of interrupts to get characters to the cpu. It would be transparent to any software. I did a write up on them 40 years ago justifying the replacement of a dz with dh saying that decreasing interrupts would increase performance on my VAX 780. It did, but just a bit. To make a big difference, you’d have to have a LOT of people banging away on serial terminals and rs-232 connected printers.
Sent from my iPhone > On Oct 30, 2022, at 09:22, Jay Jaeger via cctalk <[email protected]> > wrote: > > For an awful lot of software, holding a line until there is an end of line > is not practical. Text editors in particular simply won’t work that way. The > UNIX shell wouldn’t work in that environment either. So this character by > character interrupt is pretty standard. > > Sent from my iPhone > >> On Oct 29, 2022, at 8:02 PM, Nigel Johnson Ham via cctalk >> <[email protected]> wrote: >> >> The performance of the DZ11 is not good. It did an interrupt for every >> character, just like a DL11. The Able DMAXes blocked until a carriage return >> and then did a DNA, IIRC. >> >> Not sure about the DH and DHV11 - its been a long time. We used Able DMAXes >> on the Canadian NAPLPS system, named Telidon, but that was back in the >> 1200/300 baud days! >> >> However for vintage computer purposes, that's probably not a concern. >> >> cheers, >> >> Nigel >> >> Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU >> Amateur Radio, the origin of the open-source concept! >> Skype: TILBURY2591 >> >> >>> On 2022-10-29 14:37, Tony Duell via cctalk wrote: >>>> On Sat, Oct 29, 2022 at 6:14 PM Bill Degnan via cctalk >>>> <[email protected]> wrote: >>>> Being lazy admittedly but can these be used for single serial interfacing? >>> They will not emulate a DL11 or any similar single serial port. >>> >>> You don't have to use all 8 ports on the DZ11 card but you still need >>> the right software driver. >>> >>> That said,it would be a pity to scrap these. Surely all Unibus cards >>> are getting hard to find now. >>> >>> -tony >>> >>> >>> >>>> Bill >>>> >>>> On Sat, Oct 29, 2022, 11:01 AM Chris Zach via cctalk<[email protected]> >>>> wrote: >>>> >>>>> I have a box here of 14 DZ11 Unibus 8 line serial port interfaces. And I >>>>> have no clue why I have them. >>>>> >>>>> Anyone need some? Otherwise I'll Ebay/recycle them. >>>>> >>>>> CZ >
