XP Mode in W7 [OT in uk.d-i-y]

[The Natural Philosopher]

cripes when you have clock speeds of the order of 1GHZ plus compared with maybe 2Mhz back in the day...

[John Rumm]

Its does bring home the rate of change though, when you have a phone based emulator out performing a multi user mini computer...

(I still remember asking the admin of the first multiuser mini I used how much RAM it had - he proudly boasted 1024K ;-)

[The Natural Philosopher]

And it does bring home the code bloat when the slower minicomputer actually produced a faster user response for many users than the modern device can, for one.

[Bob Eager]

The first (multiuser) UNIX system I used had 128k...!

[Huge]

Luxury. I still remember supporting about 15 MUMPS users in 128K (not a typo) on a PDP11/40. And you lost 4K of that to the I/O page.

[Roland Perry]

In message , at

15:21:36 on Tue, 22 Apr 2014, John Rumm remarked:

Assuming that's bytes, it was typical of timesharing mainframe in the mid-late 70's. Probably made out of nine thousand 1kbit DRAM chips (to include parity). The first microprocessor I programmed had 128 bytes (a single 1024k bit static memory chip arranged as 128x8).

[dennis]

The first one I actually got my hands on (not the cdc I used via post in primary school) had a CPU that was made from about 12 sixteen inch by twelve inch pcbs. I had to do the logic design for three of the cards and never did learn how to program it.

[Adrian]

Tha were lucky. When I were a lad, we had to string white dog turds onto our dead cat's leg bones and use 'em as an abacus.

[Bob Eager]

8k! The I/O page was 4k words...

[Huge]

I might have meant words.

(But I didn't!)

[John Rumm]

This is a Prime (or should that be Pr1me?) - about mid 80's vintage. They upgraded it to 2M not long after.

[Roger Mills]

Riches untold! The HP2100[1] which I used had only 16k (or maybe we upgraded it to 24k) 16-bit words (32 or 48 kBytes). This was magnetic core memory costing about £1000 per k words - which was a *lot* of money in the early 1970's. Far cry from today, when you can get GigoBytes for peanuts.

[1] Not sure whether it was truly multi-user but it was certainly multi-tasking - capable of doing a number of unrelated things concurrently.

[Bob Eager]

To reduce this almost as far as possible....note that I never used this, although it can be run on a simulator. I dom't think my replica hardware supports it though...

[Roland Perry]

In message , at 21:40:57 on Tue, 22 Apr 2014, Roger Mills remarked:

Mainframe semiconductor memory in the late 70's was reckoned to cost £1m per megabyte.

Not long after I was selling what we'd still recognise today as a 'hard drive', albeit with an 8-inch rather than 3.5-inch footprint, cost was about £3k for 30MB. In today's money around £10k.

[Huge]

I never worked with the PDP8. I did, however, work with just about every model of PDP-11, running RT11, RSX11S, RSX11M and RSTS-E, mostly the latter 2. Interested to see that RSTS is supposedly a descendant of TSS-8.

[Bob Eager]

Yes, I never knew that before. I did work with RSTS a bit...we used to use it for teaching Humanities students before we moved them on to SCAN on the mainframe (SCAN was a text scanner and statistics gatherer, which I am about to re-implement on the PC for the 50th anniversary celebrations).

I always wanted to play woth a PDP-8, but at least I now have two replicas that work.

[Bob Eager]

We had a 128k upgrade to our ICL 4130 as semiconductor memory. It cost a lot less than that...but it was home-brewed!

[bert]

In message , Roland Perry writes

Chips!! You mean ferrite cores shirley.

[The Natural Philosopher]

No: SRAM came in, in the mid 70s IIRC

the first TTL RAM I can find was 1969: a 64 BIT chip.

If transistors/core made the first mainframes possible(1960s) TTL made the first minicomputers.(1970s)

And then MOS made microprocessors possible,(1980s+)

[Tim Lamb]

In message , bm writes

Never drove one but ISTR my first driving licence entitled me to do it along with track laying vehicles.