1401 Follow On

As of Jan 10, 2020

return to main 1401 Restoration Page - Major Topics

Table of Contents
- B.O. Evans' Comments
- 1401 Emulation in the IBM 360 Mod 30
- The 1401-H - added Jan 10, 2020

B.O. Evans' Comments
From
cctech-request@classiccmp.org Sun, Apr 14, 2019 10:00 am

Message: 1
Date: Sat, 13 Apr 2019 09:11:56 -0500
From: Jay Jaeger < cube1@charter.net >
To: cctalk@classiccmp.org
Subject: Re: Interesting article in Spectrum about IBM's System/360
Message-ID: 
Content-Type: text/plain; charset=utf-8

On 4/12/2019 1:15 PM, Eric Smith via cctalk wrote:
> The article says:
>
> Poughkeepsie?s engineers were close to completing work on a set of four
>> computers known as the 8000s that were compatible with the 7000s.
>
>
> AFAICT, that is totally wrong. The 8000 series was completely INCOMPATIBLE
> with any of the 7000 series machines. In fact, most of the 7000 series
> machines weren't even compatible with each other, though the 7040 and 7044
> had partial compatibility with the 7090 and 7094.
>
> There are some 8000 documents on Bitsavers so you can see for yourself.
> http://bitsavers.trailing-edge.com/pdf/ibm/8000/
>

Furthermore, like the 8000 series would have been, the 7000 series (and
the 700 series, and the 1400 series, for that matter) was more of a
series of *technology* rather than a series of compatible computers.

The 7000 series used SMS ECL (current mode), at least in a lot of
places, whereas the 1400 series were essentially RTL with some DTL
sprinkled in on the 1410.

For example, the IBM 7010 was an IBM 1410 done up in 7000 series
technology (and was a compatible super-set of the 1410 and, via a
toggle switch, the 1401). It had no architectural relationship with the
7090/7094, nor did the 7070 or 7080, near as I can tell.

>From "The Genesis of the Mainframe" by Bob O. Evans (an extract from a
longer memoirs document, which was not itself published, to my knowledge)


https://researcher.watson.ibm.com/researcher/files/us-bbfinkel/bob_o_evans_mainframe.pdf
[ see 5th paragraph in chapter 4 - "An Integrated Family of Products" ] "Flush with the success of the 1401 and the 1410 in process ? I was not willing to abandon those winners to join the 8000 series plan, which did not sit right with me in the first place because the 8103, 8104, 8108 and the 8112 were architecturally incompatible and I was certain compatibility was fundamentally important." [ see 4th paragraph in "Confrontation" ] "By May 1961 I concluded the 8000 series would be a serious blunder, in part because of the lack of compatibility within the systems family. I did not buy Dr. Brooks? arguments that recompilation would be acceptable to make it possible for the programming from all the dissimilar architectures of existing products to work effectively on the dissimilar architectures of the 8000 series. There were other important reasons to scrap the 8000 series plan including technology choice. Jerrier Haddad backed my decision; the 8000 Series plan was killed."

My experience with a couple of magazine authors during my career [ Quoted at the beginning of this e-mail ] tells me that many of them do not understand much of what they are writing, and errors like this 7000/8000 thing are common. Another half truth in the article reads: "The power of compatibility was demonstrated in the fall of 1960, when IBM introduced the more powerful 1410 to replace the 1401. Software and peripheral equipment for the 1401 worked with the newer machine. " That was only true to the extent that the 1410 included a 1401 compatibility mode switch, which literally changed the logic so that it became a (somewhat faster) 1401. In its normal 1410 position, it could not run 1401 programs, and vice/versa. JRJ

The 1401-H

Subject:	1401-H
From:	Ken Shirriff  	 
Date:	Thu, Jan 09, 2020 4:15 pm
At lunch yesterday I mentioned the 1401-H. Here's some more information about it. In 1967, as the 360 displaced 1401 computers, IBM re-engineered returned 1401 computers into the 1401-H. They limited memory to 4K, made memory 70% slower, and supported only cards (not tapes), and rented it for $1300/month. It was targeted at the low-end business market as well as tabulator replacement. In 1969, they had about 400 of these systems installed.

Subject: Re: 1401-H From: Bill Worthington Date: Thu, Jan 09, 2020 6:24 pm
Those of us in the DP Division (i.e. Sales) referred to it as a "Series 50" version of the 1401.

Note: Some 402/403/409 Accounting Machines and 407 Accounting Machines as "Series 50" machines also. In this case, a different size pulley was user to make them run more slowly.

Subject: Re: 1401-H From: Robert Garner Date: Thu, Jan 09, 2020 7:32 pm
Ken,

Interesting. Thanks for finding and forwarding the EDP trade article about the 1401-H.
I hadnít realized (or forgot :) that it had been so handicapped.

Looking back at my spreadsheet where I entered the quarterly inventory of 1401s (and other computers) as reported by the trade magazine Computers & Automation, it reported only 320 1401-Hs delivered (although the number appears dubiously stuck at 320):
Click here to see spread sheet .

Interesting reference to a hypothetical 360/10, that may mirror Karl Ganzhorn's reference to a 360/15 in his 2007 emails to me.*

- Robert

p.s. C&A reported ~16,000 unit-record UNIVAC 1004 systems delivered by the mid 1960s, which clearly shows that the 1401-H didnít have any effect there. The 1401-H sounds like a failure drummed up by marketing. *http://ibm-1401.info/1401Origins.html#Ganzhorn

Robert Garner's Spread Sheet from "Computers & Automation"
Dec-59 Dec-61 Sep-62 Dec-62 Mar-63 Jun-63 Sep-63 Dec-63 Mar-64 Jun-64 Sep-64 Dec-64 Mar-65 Jul-65 Sep-65 Dec-65 Mar-66 Jun-66 Sep-66 Dec-66 Mar-67 May-67 Oct-67 Dec-67 Mar-68 Jun-68 Sep-68 Dec-69 Apr-70 Aug-72 Jul-73 Jan-74 Jul-74
1401 0 1,750 3,000 3,850 5,100 5,950 6,000 6,200 6,5506,950 7,400 7,575 8,100 7,300 7,000 6,750 6,650 6,600 6,6506,680 6,6456,650 6,650 6,650 6,650 6,650 6,300 4,046 4,046 4,046 4,0464,046 4,046
1401-G 0 20 200 400 700 900 1,050 1,175 1,325 1,550 1,560 1,620 1,615 1,610 1,580 1,580 1,700 1,600 1,460 870 870 870 870 870 870
1401-H 1 320 320 320 320 320 320
1410 3 33 78 162 195 230 252 285 310 430 470 770 780 755 735 745 775 790 805 812 818 818 818 818 700 500 272 272 272 272 272 272
1440 0 0 0 70 360 630 900 1,100 1,250 1,450 1,900 2,200 2,550 2,850 3,050 3,100 3,350 3,440 3,600 3,600 3,600 3,600 3,6003,360 2,864 2,864 2,864 2,864 2,864 2,864
1460 0 0 0 110 150 255410 850 1,0251,8002,0002,1502,000 2,000 1,775 1,780 1,730 1,700 1,400 1,400 1,400 1,400 1,140 257 257 257 257 257 257
7010 0 0 0 6 8 354955 65 120 145 170 185195208 214 216 218 200 170 140 110 9081 81 84 84 8484
1400 Family 01,753 3,033 3,928 5,262 6,145 6,300 6,928 7,623 8,470 9,589 10,600 12,110 12,800 13,150 13,530 13,755 14,170 14,083 14,449 14,458 14,596 14,249 14,218 14,308 14,060 12,850 8,710 8,710 8,713 8,713 8,713 8,713