IBM 360 Model 50 information?

[dwight]

>From an emulation standpoint, latch or flop is not necessarily an issue. It is that it is a state holding element. The only potential issue is if he was doing clock cycle emulation. He'd need to understand what was originally considered a clock cycle.
Dwight

________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Paul Koning via cctalk <cctalk at classiccmp.org>
Sent: Friday, March 29, 2019 9:51 AM
To: Jon Elson; General Discussion: On-Topic and Off-Topic Posts
Cc: Ken Shirriff
Subject: Re: IBM 360 Model 50 information?



> On Mar 29, 2019, at 11:18 AM, Jon Elson via cctalk <cctalk at classiccmp.org> wrote:
>
> ...
> Oh, one other issue is the 360's had no FFs.  All storage elements were transparent latches, and they generally used a 4-phase clock.

The same is true for the CDC 6600.  Not a big surprise; a transparent latch can be made of two cross-connected gates, while a flip-flop (edge triggered) requires more stuff (four gates?).  And the 6600 uses at least four clock phases; in parts of the CPU there are additional clocks so some of the hairy parts are more like 6 or so phases.

        paul