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Transistorised 8080 microprocessor...

daver2

daver2

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This is a placeholder for a thread to see if we can get Marty's transistorised 8080 microprocessor running...

Dave
 
Hi All;
Dave, Thank You for Posting this, I didn't see it earlier, but I see it now..
First, Let me say, That I did NOT design these Boards, I got these boards from Johnny Lovqvist, who designed them..
These Boards are NOT shown on His site..
Second, As far as I know He and I are the only ones who have these boards..
I have soldered these boards up, but they have Not been Tested, I have a Board from Him that was to be for Testing, but,
there is very little and not finished software for the testing..
I have a ton of papers of printed emails between us, that are no longer on my email, as they were deleted to make room for other emails..
So, they would have to be scanned and put into a separate file..
Also, these boards are further upgrades from the original boards that He made, after learning some things from His MKII-B and C designs..
I have both of these Board sets..
I also would need to take a picture of each type of Board, and Post them Here..
If people want or would like to see what all there is of what I have..
THANK YOU Dave and all for any and all support..

THANK YOU Marty
 
Hi All;

I just uncovered the other boards, (mostly S-100 Boards) that were piled on top of the MKII-E Boards..
So, now I can get to the MKII-E Boards..
THANK YOU Marty
 
Hi;
When I try to either upload or attach a file.. It says the file is too Large..
What is the maximum size of a file that will work ??
THANK YOU Marty
 
I just tested a 1920x1280 jpg that was 1.82mb in size and that uploaded and attached fine, so your photos must be considerably larger.
 
Welcome back Marty!

Yes, there is still a limit on the upload file size. Even though it is much larger than the old site, there is still a limit. You can do one of two things:

1. Use an external file sharing site and link to the images externally.

2. Load your images into a graphics editor program and reduce the resolution so that the file size will fit onto VCFED.

I, personally, would prefer option 1 (which is what I do) as this keeps the images in the highest resolution. This can be useful fir actually reading part numbers etc. and observing small details.

His website is here https://lovqvist.net/8080-1/ for background information. Although, as Marty states, the MKII-E boards are not described.

Dave
 
Hi All;
Thank You Dave for Your post..
Do You or anyone have a recommendation of a site to use ??

" 1. Use an external file sharing site and link to the images externally. "

THANK YOU Marty
 
I have a google e-mail account - so I get a Google drive thrown in for free (up to a certain limit).

There are loads of 'free' file sharing accounts that you can get. They then charge you for incremental disk storage above the 'free' limit.

Our Church uses dropbox.

I also have an Apple email address that also comes with drive storage.

If you don't have filesharing included with your email account - then just hop onto one of the major players in the market.

Dave
 
Hi All;
Dave, I don't know IF I have file sharing, I will have to look into that..
In a note about Johnny's site You can go to
https://lovqvist.net/8080-1/8080/
For some Background information..
I will, later take a look at the pictured Boards and try to see what changes He made from this earlier design to what I have in a later design..

THANK YOU Marty
 
Last edited:
Hi All;
Dave, the Biggest change is He used BAT42 Diodes along with 1N4148 Diodes in His New circuits..
I have to find (If I can or Trace out) the New circuit and find a Schematic from the old circuit, to see the Difference..
And where or what the BAT42 did.. Where as in the old circuit, He may either have used nothing where He has the BAT42 or He had a 1N4148..
THANK YOU Marty
 
Hi All;
Dave, I might have them, I have to go and carefully Look at two notebooks full of printed pages, and then take a look at what I still have om my email..
Before, doing things the Hardway..
THANK YOU Marty
 
The BAT42 is a schottky diode. These have a lower voltage drop than a standard PN junction diode and have a much faster recovery time - hence a much higher frequency response.

Dave
 
Marty,

Yes, that makes sense now. Note that there is an error in the first URL - an extraneous '[' character.

I did read that page. Note the presence of the schottky diode and the Baker clamp diode between the base and collector of the transistor.

What I would like to know is whether his latest 'register slice' boards follow his own recommendation for the 'NOT' gate or not (no pun intended - well, a little bit).

For example, does his register slice board have the Baker clamp diodes or not, and what type of transistors and resistor values ate used (i.e. does the real board align with his posted schematic or not?

Dave
 
Hi Dave;
Thank You for the note.. I don't know Now "how to edit" that file.. There is NO edit Button !!
Let me Look and copy on Paper His NOT Schematic, and I'LL see if I can find one on a Board..
But, my best guess is that He did follow, unless He found a better circuit, thru experimenting..
That I don't know..
https://lovqvist.net/DTL/NOT/

THANK YOU Marty
 
After a period of time you can’t edit the posts anymore.

I always proof-read my posts and double-check that all the links etc. work after I create it. I still miss the odd error though...

It is nice to have you back. I see you have made some valuable contributions already on the Digital Group Z80 thread with listings not available anywhere else!

Dave
 
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