Someone's confused

Chris Zach cz at
Mon Jun 8 10:55:19 CDT 2020

I have a MV1 board set here, I'd be willing to fire up VMS to see if 
it's slower if someone wants to send me a TK50 boot tape but I'm 
guessing it would be the slowest Vax on earth.

Reasons why:
1) MV1 has only 4mb of memory to the 730's 5mb.

2) I believe the 730 accesses memory in 32 bit chunks as opposed to the 
MV1 having to access memory over the Q bus in 16 bit words. So you're 
double bucking there. Don't remember if the MV1 has a cache.

3) An 11/730 has that R80 controller. The R80 is most probably faster 
than the RQDX3+RD54, note that the RQDX3 is a slug of a controller 
compared even to a MTI ESDI controller. Possibly due to the MFM interface.

4) The 11/730 could emulate pdp11 instructions, the MV1 could not. Come 
to think of it I think the 730's floating point could do D,F,G,H while 
the MV1 could only do D,F,G.

I'm not sure why they didn't do PMI memory on the MV1, possibly because 
it's two boards already and they might already talk over CD 
interconnect, limiting the memory to one card. But the result is a 
really slow little VAX, probably slower than the 730.


On 6/8/2020 8:46 AM, Antonio Carlini via cctalk wrote:
> On 08/06/2020 13:02, emanuel stiebler via cctalk wrote:
>> Guys be nice! That's the slowest VAX, right?
>> In a small cabinet, I would take it, simply for that ;-)
> In terms of speed I think the MicroVAX I might be even slower, although 
> whether you'd notice would be questionable!
> In terms of size the MicroVAX I is considerably more convenient.
> Antonio

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