A lightbulb moment comes too late to save a mainframe engineer's blushes

Throwing light onto a frozen bit of big iron


On Call The weekend is almost upon us – a time for adult beverages and ill-judged foodstuffs. Unless, that is, you're one of the unfortunates on the other end of the phone. Welcome to On Call.

Our story today comes from "Will", who told of his time as a City of London mainframe engineer in the swinging sixties and slightly more sombre seventies.

His tale opens, as do many On Call episodes, with a telephone call. This time from a colleague who was working at a major London stockbroker.

"They had two systems in their very modern prestige computer room," he recalled, noting "it even had a visitors' gallery."

However, one of the systems had "frozen" and would not do anything. There were no warning lights, nothing to indicate things were broken, but the mainframe was locked solid.

"I was nearby," Will told us, "and went round to the customer and sure enough nothing would work.

"We even tried a POR (power on reset), which was a big no-no in those days, until it became the popular fix for Microsoft and most modern devices – which still left the system in the same frozen state."

A small crowd of techies had gathered by this stage, and all were scratching their heads as they gazed upon the controls of IBM's machine. In this case, it was a System/360 Model 40. This particular bit of big iron first made its debut in 1964 and was eventually withdrawn in 1977. A common configuration [PDF] would feature a mighty 128KB of storage, card readers, tapes and printers. Yep - all the toys a business could want.

In this case, however, the toys were broken and the machine was (relatively) silent. Ideas were tried and discarded. Right up until an engineer, running low on suggestions, jabbed a button on the front of the console. The lamp test button.

There was no helpful screen in those days, lights were the order of the day and every bulb lit up. Except one.

"This," sighed Will, "was the one that indicated that the console typewriter was out of paper."

The System/360 Model 40 was paired with the IBM 1052 typewriter keyboard, which consumed the same fanfold continuous stationery used by the bigger printers.

"The sensor was on the back of the console typewriter, so the machine had paper visible but was about to run out," recalled Will.

Nobody had thought to check the console – after all, you could see the paper and the warning light wasn't on. It must be OK, right?

Hotblack Desiato Will wasn't, and the bulb wasn't a black light that lights up black to let you know that something was wrong.

Changing it and the paper resolved the problem and the computer sprang into life.

Trickier, however, was explaining to the customer why a printer running out of stationery had taken a football-squad of techies and a large chunk of the day to resolve.

Every struggled with a problem only to find it was the fault light that was, er, faulty? Or had to make that explanation of shame to a customer? We've done at least one of those things. Have you? Confess all with an email to On Call. ®

Similar topics


Other stories you might like

  • 381,000-plus Kubernetes API servers 'exposed to internet'
    Firewall isn't a made-up word from the Hackers movie, people

    A large number of servers running the Kubernetes API have been left exposed to the internet, which is not great: they're potentially vulnerable to abuse.

    Nonprofit security organization The Shadowserver Foundation recently scanned 454,729 systems hosting the popular open-source platform for managing and orchestrating containers, finding that more than 381,645 – or about 84 percent – are accessible via the internet to varying degrees thus providing a cracked door into a corporate network.

    "While this does not mean that these instances are fully open or vulnerable to an attack, it is likely that this level of access was not intended and these instances are an unnecessarily exposed attack surface," Shadowserver's team stressed in a write-up. "They also allow for information leakage on version and build."

    Continue reading
  • A peek into Gigabyte's GPU Arm for AI, HPC shops
    High-performance platform choices are going beyond the ubiquitous x86 standard

    Arm-based servers continue to gain momentum with Gigabyte Technology introducing a system based on Ampere's Altra processors paired with Nvidia A100 GPUs, aimed at demanding workloads such as AI training and high-performance compute (HPC) applications.

    The G492-PD0 runs either an Ampere Altra or Altra Max processor, the latter delivering 128 64-bit cores that are compatible with the Armv8.2 architecture.

    It supports 16 DDR4 DIMM slots, which would be enough space for up to 4TB of memory if all slots were filled with 256GB memory modules. The chassis also has space for no fewer than eight Nvidia A100 GPUs, which would make for a costly but very powerful system for those workloads that benefit from GPU acceleration.

    Continue reading
  • GitLab version 15 goes big on visibility and observability
    GitOps fans can take a spin on the free tier for pull-based deployment

    One-stop DevOps shop GitLab has announced version 15 of its platform, hot on the heels of pull-based GitOps turning up on the platform's free tier.

    Version 15.0 marks the arrival of GitLab's next major iteration and attention this time around has turned to visibility and observability – hardly surprising considering the acquisition of OpsTrace as 2021 drew to a close, as well as workflow automation, security and compliance.

    GitLab puts out monthly releases –  hitting 15.1 on June 22 –  and we spoke to the company's senior director of Product, Kenny Johnston, at the recent Kubecon EU event, about what will be added to version 15 as time goes by. During a chat with the company's senior director of Product, Kenny Johnston, at the recent Kubecon EU event, The Register was told that this was more where dollars were being invested into the product.

    Continue reading

Biting the hand that feeds IT © 1998–2022