Table of Contents
Deadstart Section
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- Deadstart Section (this article)
Overview
The deadstart section defines the “switch” configuration of the virtual deadstart panel. It does not comport with a typical “ini” file format and each row represents a row of switches on the deadstart panel.
All numbers are octal and each row represents the corresponding row in the physical deadstart panel.
The only part of the non-comment row are the four octal digits. Everything else on the line is disregarded as “documentation or commentary information”.
Dead Start
The process of initializing a CDC Cyber/6000 series system is called dead start.
A detailed but approachable discussion of dead start is discussed in the late James Thornton’s Design of a Computer: The Control Data 6600. Mr. Thornton, with Seymour Cray, designed the CDC 6600 and therewith laid the foundation of supercomputing for decades to come. This book is available, with Mr. Thornton’s permission, in PDF form at Al Kossow’s bitsavers.org site in the directory /pdf/cdc/6×00/books and is, even today, required reading for hardware design study. (There is also in the same directory a copy of the classic text on CDC assembly language by Ralph Grishman.)
On a real Cyber, a brief bootstrap program is toggled into a switch panel—called the dead start panel—behind a door on the central processing unit. Usually, this program is toggled in but once and only changed when necessary. Often, the switch configuration was written in longhand in octal on a punch card taped inside the door. This was done for two reasons:
- Hardware engineers would often reconfigure the dead start panel during maintenance; a quick reference allowed the engineer to select easily from several configurations.
- In case the switches were accidentally jolted, the correct settings could be restored quickly and conveniently.
Dead start on real CDC hardware begins by actuating a momentary-contact switch either on the switch panel or on the operator’s console. Although the operator could override various dead start panel parameters from the console, usually, once begun, the dead start proceeded automatically without operator intervention until the operator was solicited for the date and time.
A Cyber 70/6000 series dead start panel is shown below, adapted from page 2-3 of the NOS Version 1 Operator’s Guide, pub. 60435600:
Obviously, Desktop Cyber has no real dead start panel or dead start button. The dead start panel switches are configured in the cyber.ini file, and the dead start button is “pushed” by starting Desktop Cyber.
Sample Deadstart Section
- deadstart.cybis.txt
[deadstart.cybis] ;---------------------------------------------------------------------- ; Mainframe deadstart panel. This panel configuration causes the system ; to perform a level 0 deadstart from a tape drive on channel 13, ; equipment 0, unit 0. It selects CMRD01 as the CMR deck defining the ; hardware and operating system configurations. ;---------------------------------------------------------------------- 0000 0000 0000 7553 DCN 13 7713 FAN 13, 0120 0120 for ATS 7413 ACN 13 7113 IAM 13, 7301 7301 0000 0001 wxyy w=level, x=display, yy=cmrdeck 0000