Model 40 Re: IBM 360 Model 50 information?

Curious Marc curiousmarc3 at
Tue Apr 2 05:47:48 CDT 2019

As Paul said. ALDs are schematics down to the gate level basically. Necessary to make a gate exact emulation, or debug and maintain a real machine. Used to be sent with each and every machine, but sadly not often preserved apparently. Fortunately our IBM 1401’s came with their ALDs. We refer to them every time so something goes wrong.

> On Apr 1, 2019, at 7:29 PM, Paul Berger via cctalk <cctalk at> wrote:
>> On 2019-04-01 11:25 p.m., Bill Degnan via cctalk wrote:
>> On Mon, Apr 1, 2019 at 8:59 PM Steve Malikoff via cctalk <
>> cctalk at> wrote:
>>> Marc said
>>>> Which brings us to the real problem: we don’t have 360 Model 50 ALDs.
>>> Anyone has them?
>>>> Marc
>>> And same for the Model 40 ALDs. All I have is one or two pages of the 2040
>>> ALD's and some peripheral ALD's only
>>> saved because I'd drawn artwork on the back, or they got used for book
>>> covering.
>>> I've not scanned them yet but should get to that sometime. Sadly there's
>>> not much there. A while ago I did scan a
>>> tiny fragment of the Model 40 development doc from Hursley
>>> Steve.
>> What does ALD stand for?
>> Bill
> Automated Logic Diagram    they are logic diagrams that where printed on 1403 printer with a special print train.
> Paul.

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