[cctalk] Re: 14 DZ11's for sale/whatever

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 <cctalk(a)classiccmp.org> 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 <cctalk(a)classiccmp.org> 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 >>>> <cctalk(a)classiccmp.org> 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<cctalk(a)classiccmp.org> >>>> 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