[pdp7-unix] card readers (was ald)

Bob Supnik bob at supnik.org
Wed Oct 23 04:57:56 AEST 2019


Timing and error status. The 421 responded to IORS with 4 bits of 
status. It appears that the CR01B only responded with ready/not ready. 
On the CR01B, some conditions had to be inferred by timeouts.

Mind you, I'm trying to remember this from 50+ years ago. The 
card-to-DECtape program I wrote in 1966 has a truncated source, and the 
card reader routines didn't make it.

/Bob

On 10/22/2019 11:19 AM, Warner Losh wrote:
> If they have the same IOTs, then what's different from a simh point 
> of view between the two?
>
> I don't imagine there's many people that have images of cards they'd 
> want to bring into the system via this vector, to be honest, so don't 
> take my intellectual curiosity about it as an ask to support it :)
>
> Warner
>
> On Tue, Oct 22, 2019 at 4:48 AM Bob Supnik via pdp7-unix 
> <pdp7-unix at minnie.tuhs.org <mailto:pdp7-unix at minnie.tuhs.org>> wrote:
>
>     The 18b PDP service listing (from 1972) says that PDP-7 serial #34
>     (the
>     Bell Labs Unix machine) has a CR01B. The CR01B and the 421 have
>     identical IOTs, hence the confusion. See pages 81 and 86 of the PDP-7
>     Handbook.
>
>     /Bob
>
>     On 10/21/2019 10:59 PM, Phil Budne via pdp7-unix wrote:
>     > Bob Supnik wrote:
>     >> It's probably a CR01B; I doubt if Bell could afford a Type 421.
>     > I looked at the card reader instructions:
>     >    crsf = 0706701
>     >    crrb = 0706712
>     >    crsb = 0706744
>     >
>     > and it looks like it was a 421.
>     >
>     > I don't know how much the Type 421 cost, but this was a well
>     equipped
>     > system: The Burroughs disk was one used as a swap device on KA10
>     time
>     > sharing systems, and the graphics system was custom built, and
>     > described as "as large as the CPU".  I believe it was the
>     protype for
>     > the Graphic II systems, capable of interactive filter circuit
>     > analysis, which I imagine was useful to Ma Bell.
>     >
>     > Bell Labs was responsible for the Karnaugh Map, the modern solar
>     cell,
>     > the transistor, the laser, the MOSFET, the communications satellite,
>     > the discovery of cosmic background radiation, the first computer
>     art,
>     > the CCD, CFDM ... A research powerhouse, including a lot of basic
>     > science.  It doesn't seem like any promising research topic was
>     out of
>     > bounds.
>     >
>     > I'm only surprised that the PDP-7 didn't have more than one 8K
>     memory
>     > bank (as I can't imagine they wouldn't have used it). The display is
>     > smart (there is discussion in [Sutherland68], that it may not
>     qualify
>     > for the next step on the the circle of reincarnation past the 340
>     > because PDP-9 was largely idle and available to handle display list
>     > updates) and the "hard work" (circuit analysis) was being done on a
>     > GECOS mainframe....
>     >
>     > The production Graphic II systems were PDP-9s, so I think it likely
>     > Ken found the PDP-7 as a cast off prototype when 9's became
>     available.
>     >
>     > [Sutherland68]
>     >
>     http://cva.stanford.edu/classes/cs99s/papers/myer-sutherland-design-of-display-processors.pdf
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