🚀 go-pugleaf

rnet...@gmail.com writes:

> On Friday, March 16, 2018 at 9:18:29 PM UTC-4, Dan Espen wrote:
>  
>> > The 14 came from the fact that the origial model, sold as an
>> > "elecronically programmable tabulator", had 1400 postions of
>> > internal storage.
>
>> Never heard that before but that sounds plausible.
>
> I think, underscore think, that I read it in some piece of 1401
> literature "way back when".

If I ever read that the bits in my brain must have flipped.
I only encountered a 1400 character 1401 after I'd worked on them
for a few years.  I was surprised they made them that small.
The small machine also had no index registers, but by that time
I'd stop using index registers anyway so no big deal.

>> Leaving the mystery of how they chose:
>  
>> 1410 1460 1440
>
> As to those, I suppose the 14xx came from having an instruction set
> and general internal arrangements similar to the 1401. If I remember
> correctly, the 1440 was a 1401, less parallel I/O, plus serial I/O to
> 1442 card machine, 1443 printer. Where the 1401 had I/O areas in fixed
> locations in storage, the 1440 could read into and write from anywhere
> in storage.

Yep.  Started in a shop with a 1401 and a 1460 then spent 2 years with
the 1440.  You could read/write unit record anywhere in storage but
habits die hard and I used the same locations the 1401/1460 used.

> The 1460 (hm. think hard) was a faster 1401, with I/O controls for a
> huge random access storage device.

No disk on the 1460 I used, but the 1440 had disk.
The 1311 disk wasn't exactly huge.  1 meg per drive.
Our Accounts Receivable ended up on 20 packs.  We only needed
10 packs for one generation of the data but I used split cylinder
so I could do updates by using the top/bottom of each cylinder for new/old
data during update.  We only had 2 drives.  The operator could mount the
next pack in sequence while updates where running on the other drive.

> The 1410 was a bigger 1401 which used (I think) 5 digit storage
> addresses, but was otherwise rather like a 1401.

Yep.  When I finally worked in a 1410 shop I could not tell the
difference.  The bulk of their code used the 3 character address,
only their largest programs needed the 5 character address.
Of course by that time they didn't actually have a 1410 in house
they were using emulation on a S/360.

-- 
Dan Espen