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Design flaws in classic computers

T

tezza

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What are some of the design flaws associated with classic models? Off the top of me head I can think of the following. (I've included flaws that were fixed with subsequent versions.)

  • Lack of a fan in the original Apple III
  • naked joystick ports close to the power on/off button (hence often touched) which blows the CIA chip in the C64
  • Lack of good data buffering/separation in the original TRS-80 Model 1 expansion interface
  • Lack of arrow keys and a cassette level meter in the original System 80/Video Genie/PMC-80
  • Unreliable Microdrives instead of proper floppy drives (or a floppy drive interface) in the Sinclair QL
Anyone think of any more?

I have one which promted me to post this topic. Have a look at the back of my second, beat-up TRS-80 model 1.

2009-02-22-din-plugs-on-a-model-1.jpg

Three DIN plugs all the same. The left is for Power, the middle one for Video. Did this design even lead to cooked computers? It would seem to me SO easy to accidently plug the power lead into the video output. I almost did this myself!

I guess the Model 1 came out before people gave computers to kids to play with but I'd imagine if this was a home machine, such a design would have ensured a very short life for the computer!

Tez
 
Dunno about the DIN connectors (wall wart plugs are just as bad with respect to polarity, AC vs. DC, voltage...).

But the DB-25 was employed for far too many things.
 
tezza said:
What are some of the design flaws associated with classic models? . . . Three DIN plugs all the same. The left is for Power, the middle one for Video. Did this design even lead to cooked computers? It would seem to me SO easy to accidently plug the power lead into the video output. I almost did this myself!
I guess the Model 1 came out before people gave computers to kids to play with but I'd imagine if this was a home machine, such a design would have ensured a very short life for the computer!
Click to expand...

Story! It's sometime in the 80's and I'm hooking up my TRS80 Model 1 - which I hadn't done in a while because I'm ALL Commodore in the mid 80's. Anyway, I accidentally hooked the din plugs up wrong - and that was the demise of my Model 1. It seems to me that I had to twist and push harder than usual, working from the front instead of turning the computer around to watch what I was doing - but I did get the wrong connectors in the wrong place and the TRS80 never worked again. Also as I recollect I had purposely marked the connectors with permanent ink marker, but just wasn't paying enough mind and zappo!
Now, before somebody says "NO WAY THAT CAN HAPPEN!" Let me say, I'm not 100% sure I killed it that way, but 95% sure. Like I said, I just wasn't paying attention and I was technologically now beyond the Model 1 anyway, so I didn't really much care at the time. End of story.

Design flaws ?
Well, how about that 16K RAM module that won't stay seated on the Timex Sinclair 1000 and keeps resetting the computer at the slightest touch.

How about it's 'usually' way to hard to shove cartridges into a VIC-20 slot! You practically have to hold the whole computer up on end and force the carts in. (Wish I had my old 3 slot cart expander back - it cured that problem!)

Keybounce on the old TRS80 Model 1's and the lack of proper shielding.
 
Oh, I prob'ly have quite a long list. For starters:

*Stupid arrow keys on the Model 100
*Weird power requirements of the S-100 bus
*Any pointing device that forces the user to constantly move their hands to and from the keyboard
*The general flimsiness of any portable that's likely to be dropped easily (the HP LX is built)

Ummn, I'll think of others later...

--T
 
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I don't know if this qualifies as a design flaw on IBM PCs of old (and not so old), but it always made me smile:-

"Keyboard missing error - Press F1 to continue"

LOL
 
Merlin said:
"Keyboard missing error - Press F1 to continue"
Click to expand...

I always assumed that it was implied you press F1 after plugging the keyboard back in.

Anyway one that that's always kinda irked me is metal chassis edges that act like a meat cleaver. Used to have an 8088 that was always out for blood and a 386 that's not any better.
 
From Vint..

>(about blowing up a TRS-80...)

Ah, so people HAVE done that. I thought it was a strong possibility given the design.

>Well, how about that 16K RAM module that won't stay seated on the Timex
>Sinclair 1000 and keeps resetting the computer at the slightest touch.

Oh yea, of course, I should have remembered this one. MAJOR flaw.

From Terry...

>*Stupid arrow keys on the Model 100

You know I ALMOST put this down. I used a NEC-8021a for a few years and the cursor arrangement was WAY more sensible on that machine.

>Any pointing device that forces the user to constantly move their hands to
>and from the keyboard

Indeed. Remember the hype and failure of the HP touch screen computers in the early 80s

>Keyboard missing error - Press F1 to continue"

LOL! That one always made me laugh.

>Hm, how about the Commodore B-series (B128 / 610, B256 / 710 etc)
>that has a cassette port but no code in the ROM to use it?

Really? Not the most sensible of designs I agree.

Tez
 
Vlad said:
Anyway one that that's always kinda irked me is metal chassis edges that act like a meat cleaver. Used to have an 8088 that was always out for blood and a 386 that's not any better.
Click to expand...

tee hee. back in my day on the assembly lines working at Zeos computers, I can tell you that many, many of the machines that shipped had a small pool of blood in them when they went out the door. I'm not sure how I'd react as a customer and I opened my machine and saw that. Cool, that some worker poured their literal blood, sweat and tears into building my machine, or simply gross!
 
not really a design flaw more of a labeling placement flaw. putting the warning label under the handle on the big tower ps2 systems that warns not to pick up by yourself, that you never notice till you've broke your shoulder.

another ps2 one is the p70 having the fan in the way of the slot.

and finally on some desktop systems having the bottom slot so low you have to move the keyboard to put in disks.
 
wmmullaney said:
I'd say the wireless keyboard and key layout of the PCjr
Click to expand...

Sorry, but not liking the feature doesn't make it a design flaw.

I think the original Apple III machines being so hot that the chips unseated themselves qualifies as a design flaw. A wireless keyboard (which you can use a wire with if you want to) is hardly in the same category.
 
I recently plugged the power connector into the video port on my Model I, and didn't damage anything. But, yes, this is a huge design flaw.

Other design flaws: Any computer using tinned instead of gold plated edge card connectors (like the TRS-80 Model I expansion interface).

I was reading an article in a 1983 magazine about disk errors on the Model I. It said "you all know about the eraser trick to clean the edge card connectors..." Then it went on to point out that the edge card connectors inside the external disk drives have the same problem. It just didn't cause issues as often because the cable didn't get moved around as much. Anyway, the disk directory track could be corrupted by writing to the disk when this connector had issues, making large portions of the disk unreadable. The article was about restoring the directory track using various ZAP utilities like Super Utility +.

Finally, don't forget how easy it is to destroy the RAM, or video sync circuits of a Model I by zapping the expansion interface connector with static discharge. Half the model I computer's I've seen lately have bad vertical or horizontal sync due to ruined CMOS 4000 series inverters. Why? Static discharge, probably through the expansion interface connector. But, maybe this is a long term design flaw as i don't remember this being an issue back in the '80's.
 
Its no different than the Apple key. I actually use the Windows one quite a bit, its useful if you bother to learn what it does.

hargle said:
Dang, then the windows key doesn't count? :)
Worst idea ever.
Click to expand...
 
Off topic, but there is ONE use I've ever had for the windows key. When you're in a full window program and it doesn't have a minimize button, pushing the start button usually takes you where you need to.

Otherwise, I'd strongly prefer just to use the mouse.

--Ryan
 
Don't forget the Reset key on the original Apple ][... right where most people would expect to find a backspace key.
 
Any computer that puts the clock battery _inside_ the clock chip! And those that have the battery soldered on the mother board are just slightly better.

When it comes to keyboards I hate designs that sacrifice the size of the space bar for many keys between the ctrl and alt keys:

http://www.rnid.org.uk/VirtualContent/94033/T374A_Screenphone_keyboard.jpg

Quite a modern problem though. On the same topic there is the rearrangement of the home, end, insert, delete , page up, page down buttons:

http://www.codinghorror.com/blog/images/bad_keyboard.jpg
 
pontus said:
Any computer that puts the clock battery _inside_ the clock chip! And those that have the battery soldered on the mother board are just slightly better.

When it comes to keyboards I hate designs that sacrifice the size of the space bar for many keys between the ctrl and alt keys:

http://www.rnid.org.uk/VirtualContent/94033/T374A_Screenphone_keyboard.jpg

Quite a modern problem though. On the same topic there is the rearrangement of the home, end, insert, delete , page up, page down buttons:

http://www.codinghorror.com/blog/images/bad_keyboard.jpg
Click to expand...

And don't Talk about the Lenovo laptopls. Why the $#£¤% did they put those "next web-page" "previous web-page" buttons within the arrow keys. It's pretty annoying when you write a post or an email and accidently hit one of the buttons (you'll have to write the message all over again).

But back on topic...

I'm considering CGA snow as a design flaw.
 
re: Windows Key

re: Windows Key

Yep yep yep. I haven't thought about using the windows key enough. Thanks Vlad. I mainly use laptops, which also almost always have those touch pad mice embedded on the keyboard. The touch pads are infamous for not moving across the screen as fast as our more beloved normal mouse does. Yes, I have played with the acceleration settings but it just ain't the same as a good ol' mouse. I have a new wireless mouse but I find it works great but is too much trouble to keep moving from one laptop to the next. Plus, stuff sticking out of USB connectors tends to get bend over 90 degree with me at the controls.

So.... I too will learn to use the windows key much more often. It will save me millions of mouse miles in the near future. Some skin on my index finger too.
 
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