18 Mar
2024
18 Mar
'24
8:58 p.m.
On Mon, Mar 18, 2024 at 9:57 AM Clem Cole <clemc(a)ccc.com> wrote:
The DZ11 is an eight-port mux (with short pinned modem
control and no DMA
- both causing issues).
I'm pretty sure that when we beta tested the VAX-11/780 in the summer of
1977 it had a DZ11. We only had a few LA36 printing terminals on it so we
never saw any issues with it. Not so when I started work at DEC in 1980.
The VAX-11/780 I worked on had IIRC three DZ11a supporting 24 terminals.
The lack of DMA was a big issue. We had to run our VT52s no faster than
300 baud or it brought the system to its knees.
-Paul W.