OT , computers ...

[Mark Lloyd]

You could get 704K with software that enabled the RAM at Axxxh (normally unused unless you had A EGA or higher video card). That is, if your system actually has RAM there.

[gfretwell]

Not on DOS 1.0

[Mark Lloyd]

[snip]

IIRC. with DOS 1.0, You'd have to modify the code itself.

Anyway, who said you had to be using DOS 1.0?

[gfretwell]

That was what the Gates quote was referring to. The actual memory architecture would address 1 meg but Gates decided the user only need

640k and he kept the rest for the OS. The original PC1 maxed out at 576k, 512k expansion card + 64k on the system board anyway with two 160k diskette drives and a cassette drive. I suppose you could have put another expansion card in there but you were running out of slots and that was a lot of money for 64 more k. I had a "first day ship" machine but I updated it as soon as I could lay my hands on the 256k system board that supported a hard drive and a 320k diskette. By that time the "6 pack" cards were showing up with the fill in 384k, diskette adapter, serial, parallel, game and clock. That freed up a lot of slots and 5 was plenty.

[trader_4]

Actually, the OS code itself loaded in that 640K space too. The address space above it was for video display RAM, Boot EPROM, etc.

[gfretwell]

Yes you are right, but that is still overhead for the OS.

[Mark Lloyd]

The 1M can be divided into 16 64K regions 0-F. 0 always contained RAM.

1-9 for RAM expansion (total 640K). A is reserved (later used for expanded video cards, not the original MDA/HGC and CGA. B is used for video (MDA in the lower half, CGA in the upper). C is used for add-on ROM. D-E are reserved (used for cartridges on the PCjr), and some of it was used for EMS (expanded memory). F is used for system ROM (BIOS at the top).

Later machines often had 1M RAM, with upper memory switched out. It could be switched in when there is no memory conflict, so you could actually get as much as 96K immediately above the 640K. Even more with the Upper Memory Blocks (non-contiguous RAM) later DOS allowed.

DOS 1.1 double-sided disk.

[micky]

When I saw you replied, I knew that was what you said. You pass arithmetic.

[Vic Smith]

IH (International Harvester) projected two photographic slides that I still remember from their new employee "safety" session. That was in 1968, and they're still clear in my head. One was a whole finger trailing about 18 inches of tendon stuck in a slot on a bulldozer. Its former owner was a salesman who had simply jumped from down the dozer after a sales pitch. Left his ring and finger in the slot. The other slide was a finger and tendon wrapped around a drill chuck. The pictures made it clear enough that rings fit perfectly in many slots.

[micky]

Not about rings but about remembering: When I was sojourning in law school, we had a small course called Medical Jurisprudence, taught by the acting Medical Examiner of NYC. Later he was just ME, not "acting". And he spent 2 1/2 days, 2 hours a day, showing slides of traffic accidents. I got up and left after 20 minutes the first day, and right away the other two days. I think I was the only one who left, which sort of corresponds to my not graduating. The ones who were determined to graduate probably tolerated anything.

Anyhow, I'm not going to describe it but one of the photos was so very disgusting. It barely bothers me now but even though I want to, I still haven't forgotten it 43 years later.

I volunteered for a research project about folks over 70, vitamin D, and falling. They wanted me to wear an "accelerometer", a device the size of wrist watch, that measures motion (and falling) and they wanted me to wear it 24/7 for 7 days. I told them I had to take it off to work on the car.

Would any of you work on a car wearing a wrist watch?

Anyhow, she said she'd have to call the Ph.D. in charge to see if it was okay, so I said I'd postpone it until winter when I wouldn't be doing that, but maybe I'll just forget the whole thing.

[clare]

I sometimes wore my watch working on cars depending what I was doing.