[Simh] Is it possible to simulate the first Vaxen I ever used?

[Johnny Billquist]

On 2020-03-23 17:58, Robert Armstrong wrote:
>> I think the 11/750 might have had an 8085 as well.
> 
>    I'm pretty sure the 750's console functions were implemented in microcode.  It was the only one of the "big" VAXes that didn't have a separate "computer" as the front end.  Quotations used because the 730 wasn't all that big and an 8085 is not much of a computer.

You're probably right. Took a quick peek at some documents, and couldn't 
find anything like a microprocessor in there.

Two other fun facts I know about the 11/750:

This was the only VAX for many years that actually used a boot block on 
disks. All other VAXen had the FE provide VMB for the VAX, so that 
booting was handled through VMB.

The memory bus on the VAX-11/750 is the same as for the MK11 box for the 
PDP-11/70, and they shared some memory cards. However, the MK11 never 
handled larger than 256K cards, while the VAX-11/750 was extended to 
handle 1MB cards, and eventually even had a 4MB card that could be used.

   Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol