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View Full Version : Anybody know how to work this?



Philcogrump
April 26th, 2005, 03:51 AM
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
April 26th, 2005, 07:03 PM
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
April 26th, 2005, 07:30 PM
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

Terry Yager
April 26th, 2005, 07:41 PM
Wanna sell 'er?

--T

Philcogrump
April 27th, 2005, 06:39 PM
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.