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Heathkit ET-100 learning computer

C

Chromedome45

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Joined
Jul 6, 2009
Messages
3,993
Location
Central Florida
Hey all, Who here knows anything about this system? As far as I know it does use an 8088 but that's about it. Google doesn't show to much info. It looks like the ET-3400's big brother and I also know it uses an external keyboard. So any input would appreciated as ususal. :D
 
The ET-100 is considered a "Learning Computer" like the ET-3400 but using an Intel 8088 processor. Like the ET-3400. there were several courses sold that utilized the ET-100 to run experiments and learn the internal workings of a computer.

It was offered as two models. The basic ET-100 included a processor unit with a much larger breadboard than the ET-3400 and had a detached keyboard. An ETA-100 upgrade kit was available to convert the basic unit into a full blown PC capable of running MS-DOS and PC software, complete with dual floppy drives.. However, the computer came out at the time when many vendors were switching to MS-DOS but had hardware that wasn't fully compatible with the IBM PC. You had to have a special version of DOS made for their machine. The ET-100 is one of those machines. There was a third party mod to bump the RAM up to 640K and give the unit the ability to run most of the IBM PC software. Zenith never offered a hard drive for this computer.

These computers are very rare now. From time to time you may see a basic model on eBay, but usually it is missing the keyboard so it's pretty much useless. Just last week an ETA-100 unit sold on eBay for $660 and it didn't even have the external floppy unit. The external floppy unit uses conventional 5.25" 360K or 1.2MB drives and a standard floppy cable.

Last weeks eBay auction:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320504899274&ssPageName=STRK:MEWAX:IT

You can tell the upgraded model by looking at the rear panel. An upgraded unit will have a Floppy connector and a Color Video port.
 
Hey Northern neighbor what else can you tell about it. Have any documents? I was wondering about the EA-100 you mentioned? The main reason is I was second highest bidder and won after winner didn't pay! Don't ask how much I'll just Ouch in the wallet ;)
 
Chromedome45 said:
Hey Northern neighbor what else can you tell about it. Have any documents? I was wondering about the EA-100 you mentioned? The main reason is I was second highest bidder and won after winner didn't pay! Don't ask how much I'll just Ouch in the wallet ;)
Click to expand...

The unit shown in the listing is an EA-100. So you are going to need a monitor and external 5.25" 360K or 1.2MB floppy drives to have a full system. I see the Heathkit and Zenith floppy units on eBay a couple of times a year, but any external floppy box with 5.25 drives listed above will do.

Monitor:
Monochrome using an RCA jack
**OR**
9-pin RGB TTL Color monitor. I am using a Zenith ZVM-133 RGB monitor. Other monitors can be used, but you will have to make a custom cable and possibly set some jumpers on the video card depending on what sync signals the monitor you use requires. Pin-outs for the EA-100's color video are in a file accessed through the link below:

http://www.mediafire.com/?nzhzy2ynzzm

I have a full set of ET-100 and EA-100 manuals, both User manuals and Technical manuals (with schematics)scanned into PDF format if you need them. I also have boot and Utility disks in ImageDisk format (just created them yesterday). I also have some of the course books for the system, but they aren't scanned yet.
 
Yep I could use the EA-100 and ET-100 user manuals and technical manuals if you could send them to me. What does switchblock 201 do? Has a lot of EA-100 settings and I have no idea what it they are for. I could also use the disk images if you could send them too. By the way how did those Northstar disks work out?
 
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Chromedome45 said:
Hey Northern neighbor what else can you tell about it. Have any documents? I was wondering about the EA-100 you mentioned? The main reason is I was second highest bidder and won after winner didn't pay! Don't ask how much I'll just Ouch in the wallet ;)
Click to expand...

Hi
I often wonder how many times these dropout bidders are shill bidders.
I've made it my policy to never take such unless the amount is equal
to the next lowest bid, not from the dropout.
I had one seller tell me I was obligated to pay my highest bid.
I told them that they should check with ebay. You are specifically
not obligated to do anything.
That was in the day when you could identify the bidders and I looked
that there previous purchases. It seemed that they only bought items
from 2 sellers ( in the same town ), regardless of what the item was.
It sounded like a shill bid to me so I eventually just ignored them.
Dwight
 
I recently came into possession of four of these, complete with keyboards and three Zenith Data Systems monochrome displays. Three of them will power up and say something to the effect of "ROM Monitor 16k RAM".

Chuckster_in_Jax, would you be willing to share your scanned manuals? I'd really like to be able to determine if any of them are in working order.
 
Three working ET-100s!

Three working ET-100s!

Of the four ET-100s I have, three are confirmed working. One was utterly dead, but it was still useful as cap C206 on another was bad and causing really strange errors.

Each unit has a keyboard and monochrome Zenith monitor if anyone here is interested. I'm going to let go of two of them.
 
Great find Mister. What'll help folks is where are you located? Shipping so often costs as much or more than the systems these days it's great to post your location for local collectors in your area.

- John
 
I'm pretty close to you, Chromedome45; I'm only about three states to the north of you in central Kentucky. You'll forgive me if I don't want to be more specific on a publicly-accessible forum.

Also, to everyone, I feel I should be clear that these _do not_ have the EA-100 upgrade kit. They have 16KiB of RAM, a monitor and assembler in ROM, and monochrome composite video.
 
Chuckster_in_Jax: I have a full set of ET-100 and EA-100 manuals, both User manuals and Technical manuals (with schematics)scanned into PDF format if you need them. I also have boot and Utility disks in ImageDisk format (just created them yesterday). I also have some of the course books for the system, but they aren't scanned yet.
Click to expand...

I'm trying to locate these manuals ... are they still available?

Many thanks, Gary
 
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