Author Topic: EEVblog #955 - World's First Portable Computer Teardown  (Read 8721 times)

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Offline djos

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EEVblog #955 - World's First Portable Computer Teardown
« Reply #25 on: December 15, 2016, 04:40:43 pm »
sadly I sold my much loved C 64  :-[  as upgraded to a new IBM, so we could get into the new fad, at the time, called the World Wide Web.  ;D

I was lucky, I got given this one by a family friend who found it in their garage.

Ps Dave would likely be bored silly by a c64 tear-down as there's bugger all in them (heatsinks added by me).

« Last Edit: December 15, 2016, 04:44:19 pm by djos »
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Online Towger

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #26 on: December 15, 2016, 05:16:24 pm »
Hmm... Let's hope, for Dave, he won't get caught by the Osborne Effect and fail to sell any of the BM235's now ;)

Problem is he has already missed the Christmas market and those of us with Kids will he broke for months after it next year.

I C64 teardown would be interested if he could get all the revisions.  It is a good example of electronic miniaturisation over the years.
 

Offline djos

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #27 on: December 15, 2016, 05:27:17 pm »

I C64 teardown would be interested if he could get all the revisions.  It is a good example of electronic miniaturisation over the years.

Not really, all revisions have the same chips, 2x VIA (keyboard and joysticks), SID for audio synth, VICII for video, 6510 CPU, ram chips, a Rom chip a PLA and not that much else.

Here's the '85 and '92 service manuals if you are interested.

https://www.dropbox.com/s/2ew80uo58qoymr0/C64_Service_Manual_314001-02_%281985_Feb%29.pdf?dl=0

https://www.dropbox.com/s/xgdpis2nuaya0lx/C64-C64C_Service_Manual_314001-03_%281992_Mar%29.pdf?dl=0
The impossible often has a kind of integrity which the merely improbable lacks.

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Offline Fungus

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #28 on: December 15, 2016, 05:42:45 pm »
I C64 teardown would be interested if he could get all the revisions.  It is a good example of electronic miniaturisation over the years.

Nah, I don't think they changed much.

(they wouldn't dare - almost every C64 game relied on hardware bugs and undocumented 'features' to work  :) )

 

Offline djos

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #29 on: December 15, 2016, 06:05:57 pm »


Nah, I don't think they changed much.

(they wouldn't dare - almost every C64 game relied on hardware bugs and undocumented 'features' to work  :) )

Exactly, when they released a "bug fixed" SID chip in later C models, they broke a bunch of games that where using the bugs to do things the SID wasn't supposed to be capable of. :D
The impossible often has a kind of integrity which the merely improbable lacks.

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Offline Moshly

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #30 on: December 15, 2016, 06:31:41 pm »
Actually there are 4 cost reduced versions of the C64

Original board
Integrated TTL logic into custom PLL Clock chip.
Changed DRAMs to 2x 64k by 4 (replaced 8x 64k by 1)
C64C, integrated more glue logic into the PLA, Changed to HMOS chips from NMOS (Smaller PCB)
C64C, moved the color SRAM chip into the PLA

I think sending Dave more obscure stuff is more interesting, Commodore, Atari & Apple stuff is too common.

How about some 80's Dick smith offerings like ->
Dick Smith VZ 200 / 300, Dick Smith CAT (Apple 2 clone) or Dick Smith Wizzard.
 

Offline djos

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #31 on: December 15, 2016, 07:24:50 pm »
Actually there are 4 cost reduced versions of the C64

Original board
Integrated TTL logic into custom PLL Clock chip.
Changed DRAMs to 2x 64k by 4 (replaced 8x 64k by 1)
C64C, integrated more glue logic into the PLA, Changed to HMOS chips from NMOS (Smaller PCB)
C64C, moved the color SRAM chip into the PLA

I think sending Dave more obscure stuff is more interesting, Commodore, Atari & Apple stuff is too common.

How about some 80's Dick smith offerings like ->
Dick Smith VZ 200 / 300, Dick Smith CAT (Apple 2 clone) or Dick Smith Wizzard.

Doesn't really count as "miniaturization" tho does it.

The Commodore 64 DTV, now that's miniaturization!

https://en.m.wikipedia.org/wiki/C64_Direct-to-TV
The impossible often has a kind of integrity which the merely improbable lacks.

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Online Towger

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #32 on: December 15, 2016, 07:41:10 pm »
The Commodore 64 DTV, now that's miniaturization!

Jerry's pension fund is the leftover C64 asic dies.
 

Offline djos

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #33 on: December 15, 2016, 07:41:58 pm »
The Commodore 64 DTV, now that's miniaturization!

Jerry's pension fund is the leftover C64 asic dies.

:D
The impossible often has a kind of integrity which the merely improbable lacks.

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Offline rbm

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #34 on: December 16, 2016, 01:57:20 pm »
It is not the worlds first portable computer. Not by a long shot.

Released in 1975...
https://en.wikipedia.org/wiki/IBM_5100

(I actually had one of these in my home in 1980.)
Man, I remember those things vividly!  I worked for IBM at the time those portable computers were introduced and I used those in the QA lab to setup production tests on manufactured equipment.  They were awesome machines but APL was a Bi*CH to learn.

Part way through the EEVblog video, Dave comments on the RAM chips on the Osborne being whatever came to hand.  I can believe that there weren't the same established supply chains that we have today available to a SMB like Osborne at that time (1982) so they had basically no choice but to use what little stock they could get a hold of.  It's so easy now a days to sit back and enjoy the convenience of ordering what-ever exotic part we may dream of found through Internet and get it supplied from unlimited stocks at global supply houses, but it wasn't always so, especially in the early days.
- Robert
 

Offline cengland0

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #35 on: December 19, 2016, 09:05:13 am »
When Dave tears down the floppy drive and you see a switch on the left, he claims that is to detect if a disk is in the drive.  I actually think that is to detect the write protect notch.  If the notch is there, you cannot write to the floppy.
 

Offline djos

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #36 on: December 19, 2016, 10:27:42 am »
When Dave tears down the floppy drive and you see a switch on the left, he claims that is to detect if a disk is in the drive.  I actually think that is to detect the write protect notch.  If the notch is there, you cannot write to the floppy.

I checked my Commodore 1541 floppy drive and you are correct, it's the write protect detection switch.

Who recalls turning DSDD disks into Flippies with a notching tool so they could use both both sides? :D
« Last Edit: December 19, 2016, 10:32:07 am by djos »
The impossible often has a kind of integrity which the merely improbable lacks.

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Offline Brumby

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #37 on: December 19, 2016, 11:01:57 am »
I can remember taking 8" floppies from an IBM mainframe (microcode updates) and punching a hole so they could be used on a TRS80 model II.  They worked - and could hold around 1 MB!!
 

Offline djos

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #38 on: December 19, 2016, 11:28:41 am »
I can remember taking 8" floppies from an IBM mainframe (microcode updates) and punching a hole so they could be used on a TRS80 model II.  They worked - and could hold around 1 MB!!

Nice, 1MB was a ton of data back then, especially when you consider how much a 10MB HDD sold for back in the 80's!!!  ::)
The impossible often has a kind of integrity which the merely improbable lacks.

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Offline meeko

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Re: EEVblog #955 - World's First Portable Computer Teardown
« Reply #39 on: December 20, 2016, 09:09:28 am »
Who recalls turning DSDD disks into Flippies with a notching tool so they could use both both sides? :D

We didn't need any fancy-schmancy notching tool!  Just another disk to use as a template and a pair of scissors.  While walking 10 km, barefoot, through 3 m of snow, uphill (both ways) to and from school!  :-DD

The hard plastic of a 3.5" disk was a little tougher to get through to make DD disks into HD ones...  I did have a specific tool for that.  It fit over the disk the same way, but instead of having a punch, you screwed a cutter down that bored through the shell.
 

Offline djos

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EEVblog #955 - World's First Portable Computer Teardown
« Reply #40 on: December 20, 2016, 09:21:14 am »
Who recalls turning DSDD disks into Flippies with a notching tool so they could use both both sides? :D

We didn't need any fancy-schmancy notching tool!  Just another disk to use as a template and a pair of scissors.  While walking 10 km, barefoot, through 3 m of snow, uphill (both ways) to and from school!  :-DD

The hard plastic of a 3.5" disk was a little tougher to get through to make DD disks into HD ones...  I did have a specific tool for that.  It fit over the disk the same way, but instead of having a punch, you screwed a cutter down that bored through the shell.

Lol, yeah I used scissors for quite a long time, I just used another floppy as the template and a texta to mark the cut.

I had a specific tool for doing the 3.5" disks too, it was a really cheap and nasty soldering iron with a pointy round tip. :D
The impossible often has a kind of integrity which the merely improbable lacks.

Visit my Tindie store for Tandy 1000 Adapters for EX, HX, SX, SL, TX & TL etc
 


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