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Engineer chic of the day.

Me too. Had any headway yet/ Would need help

There is always delay caused by capacitance so it's never zero even if drives are solid state.

That sounds like a Telex machine... the channel CuriousMarc has a great look at one

Kind of sounded like cache,the way it was described

Cache memory was measured in KBytes back then. I recall working on a Honeywell mainframe back in 1982 that had 4KB of cache memory.

It's basically main system RAM. The CPU will have a very limited instruction cache.

It is mainfram storage so yes RAM. 8 MB was expensive. The 3033 was at its launch in 1977 100 % faster than the previous fastest processor. Expect the leasing cost over 4 years for 8 MB to be millions.

It sounds so small until you remember that csects and dsects were limited to 4k.

Funny how halon stopped being permitted when the computer equipment became less valuable than the average lawsuit payout for wrongful deaths.

@@jblyon2 honestly, I think "They" expected operators to all run out, and press the Bid Red Halon Button _as they were leaving._ Of course, sometimes idiots put the halon button deep inside the room, far from the door.

@RonJohn63 Lots of bad designs out there. I saw someone with a story posted somewhere that the halon button at the loading dock entrance was next to 2 other buttons, one of which was also red and commonly used. Naturally it got hit by mistake one day and everyone had just enough time to get out, but they all got out thankfully. I've also heard of similar bad designs for the quench buttons for MRIs.

@@jblyon2 "I saw someone with a story posted somewhere". lol

​@@jblyon2oh, they still use fire suppression systems with similar properties to halon in new installs. They are just hcfc or hfc based not CFC based. I have to deal with one at work.

And it was stunningly loud (even under the insulated box).

Lol of course it's Tiger Rag

🤣

All I could think was "This is a pretty nifty music box, it even prints...oh...oooooh...that printout is the demonstration...ahhhh"

Agreed. When you program in machine language and optimise every single step, you can do amazing things with low resources. Sadly, today much of the software we use seems to grow to take up all the resources, with terrible optimisation. That said, the software is far more complex I guess. My first computer at 1k of RAM... was amazing how clever some people got writing code for it!

3270 terminals were _highly_ intelligent,_ having their own CPUs and "display programming language". Combined with CICS, they were an early form of client-server web computing, where the end user types everything into the terminal and then pressed the XMIT (aka Send) button. That transmitted the whole block of data to the mainframe. Until you pressed XMIT, the mainframe completely ignored you. This is in stark contrast to minicomputer OSs like Unix/Linux and VMS, where the OS must process each and every keystroke and cursor movement. Bottom line: web-based client-server computing is just a new and horribly inefficient version of a programming paradigm that's been around for *55 YEARS.*

... there was a lot of swapping and let us not forget "initiators", job batching and job prioritization

The IBM mainframe does not have to keep an separate active program for state for each user. When I used to program CICS, back in the 1980s, you could store context in hidden areas on the user's terminal and/or in something call TSQ - Temporary Storage Queues. When the user pressed SEND, the CICS program would fetch the context based on the data from the user, do the work and return a new screen image back to the user. I do some PHP web programming these days and my programs are designed very much like a CICS program since there are cookies that come from the user and I can thus restore the context, do the work and return a page back to the user. The web server needs to remember little of a particular user's transaction. The web server has the equivalent of TSQs with session info. The comment about OS processing every keystroke is possibly true for a UART connection but I think Ethernet sends info in blocks(?) It is definitely not "... horribly inefficient ..." Computer folks are not going to make badly designed web servers.

@@ablebaker99it's not the web servers, but the slow and bloated JavaScript fed by the web server.

Indeed.