Fun with Patel

[gfretwell]

I got a call from "windows support" today telling me I had a problem with my machine. Normally I just tell them to perform an unnatural act with their mother but today I decided I would play along as long as they would let me. This "english as a second language" guy gave me the "grave danger pitch and then started telling me to type in a web address and I said it keeps saying "bad file or command name". He asked what was on my PC screen and I said "C:>" They had me reboot a couple times and I made that take a long time, "wait, I need to set the clock" etc. They got second level involved and he asked how I get to the internet and I said I just use E-mail. He asked how I do that and I said AOL. He kept telling me there must be an internet address bar there and I said I don't see one and I have never used it. He asked what version of AOL I was using and I said I don't see a version, it just says "AOL for DOS". He asked what kind of machine I had and I said "IBM Personal Computer XT". I acted confused when they asked me about the OS. I said it was the one that was on it when I bought the machine in 1985. After a minute or two of violent keyboard clicking I said "DOS 2.1" After another guy got on the phone, they finally asked me if I had windows and I told them "no, that was the tool of satan". They hung up.

I tied up 2 or 3 guys for 15 minutes. Maybe they will take me off their list now.

[philo]

I have in my antique computer collection one of those Compaq "sewing machine" computers.

It only works with Dos 2.1

so you made a damn good choice there :)

[gfretwell]

I remember upgrading my PC1 (original 5150) to DOS 2.1 when I added the hard drive and new system board with HD boot bios.

[philo]

I did a lot of experimenting.

Dos 1 floppies can only be read from a machine running Dos 1

and Dos 2 floppies can only be read from a machine running dos 2

Once Dos 3 came out, it could read any version of Dos above it and visa versa. The commands would not necessarily work but at least there was some level of compatibility.

[gfretwell]

Huh? That is not my experience. I was able to read and copy my DOS

1.0 diskettes with other versions. The last time I copied them it was in the DOS box of W/98. You do need a drive capable of reading 128k disks tho. All "real" IBM drives will do it. YMMV on a clone. You do have to be careful tho. You need to do a 'diskcopy" or you will end up with a disk that is formatted at whatever it was, typically 256k or 1.2m. You can't really make a 128k disk on 1.2m media tho. The oxide is different and it will not read on a 128k or 256k drive.

[DerbyDad03]

I installed literally thousands of 5150's when I worked IT for a former Fortune 500 company. The scientists in the Research Labs got them first, then management, then the 5150's replaced the hundreds of Radio Shack TRS-80's that we had installed for the secretaries a few years earlier.

Every 5150 had to have an IBM-3270 terminal emulator board installed so employees could connect to the mainframe. It was interesting to watch some employees use them as nothing more than glorified terminals while other's took full advantage of the "computing power" at their fingertips.

[DerbyDad03]

We used to punch index holes in the B-side of 5" and 8" floppies to use them as dual-sided floppies long before dual-sided was an industry standard.

We told the users that we did this for that they should be cautious with what they stored on the B-side because they were not "certified" by the manufacturer, but we saw no greater failure rate on the B-side than the certified side.

It was never the floppy per se that failed, it was typically the drive that trashed the floppy. Static was the biggest problem. We had TRS-80 units that were so bad that the users would touch the plastic case of the keyboard and the daisy wheel printer would spit out a character.

We hung copper straps from the sprinkler system and attached grounding bracelets to them. Secretaries would ground themselves to the building before sitting down to do their word processing.

[gfretwell]

There were a few flavors of that card and several software options. IBM internal had a pretty neat one that ran with very low overhead, supported four 3270 sessions and a DOS session, that could also be running W/3.1 You could have a bunch of stuff going on if you were running a 286 with a big memory expansion card in it and the right extended/expanded memory drivers loaded.

This was the one I had on my desk..

[philo]

When I tried to read known working Dos1 floppies from another version of DOS all looked corrupted.

Same with Dos 2

(shrug)

[philo]

I did a different bit of experimenting.

I still have an IBM PS/2 with the 2.88 meg floppy drive.

Supposedly it required a special floppy, but I had no problems formatting a standard 1.44 as a 2.88

[philo]

Just to see if I could do it...maybe ten years ago or so I got a Zenith Data Systems 286 with 512 megs of on-board RAM

In my junk box I had an ISA memory expansion board and was able to install 16 megs of RAM. I even had the software so that DOS & Win3.1 could recognized it.

[DerbyDad03]

If I recall correctly, there were more than a *few* flavors. It seemed like they changed flavors with each subsequent order of 5150's as well as when they ordered spares. You never knew which emulator was installed until you got on site and looked at the user's machine. Sometimes we had the correct spare in stock, sometimes we were changing cards as well as software.

Regardless, it sure beat swapping out an entire 3270 terminal.

...snipp...

[gfretwell]

IBM PS/2 does not honor the media sense hole. It all depends on what the media descriptor byte says in the boot sector. That can get you in trouble if you are dealing with newer IBM PCs or clones. I suppose you could format a 720 disk to 2.88 but it may not be reliable. I did have a bunch of misformatted disks (720 and 1.44) around and they seemed to work just fine tho. The one that didn't work was mixing up the 5.25" formats.

[gfretwell]

Until the 3180s came out, we fixed 3270 terminals. (cards, power supplies and even the CRT) The 3180 was a FRU. Cut open the box and plug in a new one.

[DerbyDad03]

Speaking of experimenting...

The TRS-80's had a 3-bay 8" floppy expansion unit. It was notorious for corrupting disks. We'd swap out a drive, test the new one and then put the case back on. 2 hours/2 days/2 weeks later, we'd get called back for the same problem.

We finally figured out that if we left the (I forget which) 3 screws along the (I forget which) side out, we never got called back.

We began to remove those screws before even delivering the units to new users and the failure rate plummeted.

We also learned to open up every single keyboard and run a ground wire from the circuit board ground to the plastic case prior to delivery. Static related disk drive failures were reduced dramatically.

I think that there was something like 4 modifications that we made to the machines before delivery just to keep the failure rates down. Those are the dollars that never show up on the correct budget reports. Instead of having the units delivered straight to the end-user's office where we could just open them up and put them on their desk, every unit had to be delivered to our shop, unpacked, modified, repacked and then taken to the end-user.

Some purchasing agent probably got a bonus for negotiating a sweet deal on the "sales" side of the books, meanwhile the IT maintenance budget for each department was getting hammered before they even received a computer. But, hey, those are "internal dollars" so they don't matter.

Did I mention that this was a *former* Fortune 500 company?

[philo]

Since I did this experiment long after the PS/2 was obsolete, it could simply be that the floppies at that time were better quality than those that existed at the time the PS/2 would have been in production.

From time to time I thin out my collection of vintage computers but doubt I will ever part with that PS/2

[philo]

tter.

LOL

I never had a TRS-80

but when I got my Ti-99/4, the ability to save my programs on a cassette seemed amazing.

It was just like having a miniature main-frame!

[gfretwell]

I always suspected that as newer media came along, all disks were made for that and were backward compatible,

I am out of the PS/2 business but there is still a pretty active PS/2 newsgroup. That is where I donated all my books and hardware.

[DerbyDad03]

Depending on the situation, we either swapped 'em out and repaired the bad unit in the shop or fixed them on-site. It depended on the symptoms, whose terminal it was, location, etc.

e.g. in a secure area, we'd sometimes swap them on a cart *outside* the area and let the customer hook the good one back up.

When we moved up to PC's things got a little more complicated.

[gfretwell]

I missed all of that stuff, Until the 80s, I could get mainframe time just about any time I wanted it. In the 60s and early 70s we had the whole system for a few hours a week at a half dozen customers. I could get a partition just about any time I liked. A program I wrote, allowing concurrent maintenance on anything running DOS (360-370 style) pretty much made taking the system obsolete for the guys who used it. I got into the home computer biz with the IBM PC and a "first day ship" PC1. I bought it second hand when an IBM guy I knew upgraded to the brand new PC/AT.

As you saw, I built my first AT from parts (there is no part number for a case)