VAX 780 on eBay

Chris Zach cz at
Sun Jan 2 23:11:43 CST 2022

Yup. The 8600's (UMBC1 and 2) were connected to Bitnet, and I was a 
little Bitnaught until I found AI. It might have connected through the 
Gandalf network or something else, I'd have to check old printouts.

> Can I ask for a rough translation in to comparative VAX Units of 
> Performance (VUPs)?  I /think/ that the VAX 11/780 was 1 VUP.

Kind of like MIPS, but I think they were going for throughput. The 780 
may have had the same CPU speed as the Microvax II, but anytime you hit 
disk on the MV you were slugging down to the Q-Bus speed, going through 
a 4mb memory map window, and the RQDX3 wasn't either fast or very good IMO.

The 780 would plow through the MASSBUS channel interfaces directly 
attached to memory (well, on a 780 everything went SBI) and 
RM03/RM80/RP07 drives were way faster than RD54's. And you could go to 
CI bus to talk to an HSC50 which could do more interesting stuff with 
RA81's and 82's.

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