Modifying microcode

[Antonio Carlini]

On 01/06/18 18:40, Eric Smith via cctalk wrote:
> On Fri, Jun 1, 2018 at 11:08 AM, Robert Armstrong <bob at jfcl.com> wrote:
>
>>> Eric Smith <spacewar at gmail.com> wrote:
>>> The control stores of the 11/785, 8600, and 8650 were entirely WCS.
>>>
>>> All other VAXen had (relatively) large ROM control store and tiny WCS or
>>> patch store.
>>    You forgot the 11/730 and 725.  The KA730 used 2901 bit slicers and the
>> control store was entirely in RAM.  After power on it was a paperweight
>> until the 8085 CFE loaded the microcode.
>
> Thanks for the correction! I've never used those models.
>

In the Digital Technical Journal #2 (the one that describes the 
development of the MicroVAX II)

they say that they used the VAX-11/730 as a testbed

the 78032 chip. The VAX-11/730 was chosen because it was "an entirely 
'soft' machine".


(The VAX-11/725 is essentially the same hardware but in different 
packaging).


Antonio


-- 
Antonio Carlini
arcarlini at iee.org