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Anybody know how to work this?

Philcogrump

Experienced Member
Joined
Jan 15, 2005
Messages
62
Location
Texas
I have this simple 8085A computer made by EKI, Inc. with a hexadecimal keypad and a row of eight LEDs for binary output. There used to be two 7-segment displays next to the LEDs, but I ripped them out because certain segments were shorted. Anyway, I believe this thing drives eight relays and the memory works (RAM is a 8155 if I remember correctly which is a RAM and I/O chip in one). With my knowledge on computers, I think the display uses shift registers to shift the numbers to the next available display when a key is pressed (ie. 53 in binary on the LEDs, if you press key D, then the display shows 3D, key A pressed then display is DA and so on). I have verified that the memory works by selecting an address location, storing a number, and recalling it back. However, that is what this thing does in program position, if I slide it in RUN, it pretty much does nothing and I have a list of 8085A opcodes, but I have no clue how to make something work and see an action. I have some pictures here:

http://members.aol.com/philcogrump/temp/

The pictures are eki1.jpg, eki2.jpg, eki3.jpg, and eki4.jpg. There are three red buttons on the controller board for address, write, and read. There is a switch on the processor board for program and run. Often, when it is in run mode, all LEDs light up and nothing much. Any ideas what this thing is and/or how to work it?
 

Exluddite

Experienced Member
Joined
Oct 8, 2004
Messages
81
Location
Manahawkin, NJ
8085 datasheet page : http://digilander.libero.it/rar2k/TRS80/Intel8085A.html
(although you did say you had a list of opcodes)

The 8085 datasheet should be here:
http://www.datasheetarchive.com/search.php?search=8085&sType=part

The 8155 datasheet should be here:
http://www.datasheetarchive.com/search.php?search=8155&sType=part

This might be the same company that made it:
http://www.eki.com/index.html?lang=en-us&target=d8.html

I'd imagine that this is similar to a microcontroller interface, difference being you can't use C (or even assembly) but you have to punch in straight hex codes. I'm sure you could also program it from a parallel port or usb, but I have no idea where to find the software (or if it's even been written).
 

Allison

Experienced Member
Joined
Mar 17, 2004
Messages
83
Location
Ma
Re: Anybody know how to work this?

Philcogrump said:
I have this simple 8085A computer made by EKI, Inc. with a hexadecimal keypad and a row of eight LEDs for binary output. There used to be two 7-segment displays next to the LEDs, but I ripped them out because certain segments were shorted. Anyway, I believe this thing drives eight relays and the memory works (RAM is a 8155 if I

snippage

Find a manual for an intel SDK85 as it's very similar. There were many similar boards out there for hobbiest use and as simple CPU/system demonstrators.

Basically from the keypad you can do a few things like:

input a ram location.
Display a ram location.
Change the contents of a ram location.
Some may even Display saved Registers and allow alteration.
And they will Run a program input by the user at a given location.

Allison
 

Philcogrump

Experienced Member
Joined
Jan 15, 2005
Messages
62
Location
Texas
Thanks for your help, I'll contact EKI, apparently they still sell those systems for students and see if I can get a manual for it.

No, I am not selling this thing.
 
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