18 Mar
2024
18 Mar
'24
9:20 p.m.
On Mon, Mar 18, 2024 at 10:58:04AM -0400, Paul Winalski wrote:
On Mon, Mar 18, 2024 at 9:57???AM Clem Cole
<clemc(a)ccc.com> wrote:
I was one of about 40 students working on a terminal hooked to a 780.
I put up with it for a semester and then bought a 4mhz 128KB Z80
CPM machine. It was not that fast but it was all mine. I was more
productive on the Z80.
I got a $2000 loan to buy it. Taught me that I really really hated to
owe the bank.
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.