RetroBrew Computers Forum
Discussion forum for the RetroBrew Computers community.

Home » RBC Forums » General Discussion » Mini MC14500 board
Mini MC14500 board [message #4919] Sun, 15 July 2018 03:43 Go to next message
trick-1 is currently offline  trick-1
Messages: 119
Registered: September 2016
Senior Member
Hi Folks

I stumbled across the MC14500B https://en.wikipedia.org/wiki/Motorola_MC14500B 1bit CPU and then further research I found reference to some work done way back on a vector array processor using the same CPU (It was @ a Canadian university and for the life of me I cannot find the article right now.Wink Basically the system had 1 CPU per bit on the data bus, N layers some address decoding and buffering to create a vector array processor on a budget.

Any way, one cold and wet weekend later I have put a very simple board together as a proof. The board will run standalone and can be programmed/clocked/reset/data entry via the switches. The board should allow for experimentation with the CPU. I have designed it so that I can connect 8 of them into prototype board and test out some theories.


Attached is the image out of KiCAD of the board that I have just sent for manufacture.

Happy to take questions

If it all works I will post the board and the files.

Cheers

Richard
Re: Mini MC14500 board [message #4920 is a reply to message #4919] Sun, 15 July 2018 04:11 Go to previous messageGo to next message
trick-1 is currently offline  trick-1
Messages: 119
Registered: September 2016
Senior Member
UPDATE: found the article! The machine was called VASTOR. See the attached article.
Re: Mini MC14500 board [message #4957 is a reply to message #4920] Fri, 27 July 2018 23:31 Go to previous messageGo to next message
trick-1 is currently offline  trick-1
Messages: 119
Registered: September 2016
Senior Member
So the board has come in and looks OK (see attached). Just got to wait for the MC14500 to come in so I can test.
Re: Mini MC14500 board [message #4958 is a reply to message #4957] Fri, 27 July 2018 23:58 Go to previous messageGo to next message
pbirkel is currently offline  pbirkel
Messages: 59
Registered: October 2015
Member
Richard: Looks nice! If you have any PCBs left over I'd be interested in trying out one of them :->. THX.
Re: Mini MC14500 board [message #4959 is a reply to message #4958] Sat, 28 July 2018 03:36 Go to previous messageGo to next message
trick-1 is currently offline  trick-1
Messages: 119
Registered: September 2016
Senior Member
Should be 4 left over from this run.

Let me make sure the board works.

if it does then I will put it up in the others section and mark it as available for order
and maybe even do an initia demand based run
Re: Mini MC14500 board [message #4960 is a reply to message #4959] Sat, 28 July 2018 04:05 Go to previous messageGo to next message
pbirkel is currently offline  pbirkel
Messages: 59
Registered: October 2015
Member
Richard: Thank you.
Re: Mini MC14500 board [message #4963 is a reply to message #4959] Sun, 29 July 2018 00:10 Go to previous messageGo to next message
trick-1 is currently offline  trick-1
Messages: 119
Registered: September 2016
Senior Member
We'll board has gone together OK - see attached photo

I used the wrong resistor foot print but that's not a big issue for round one.

Now all I need is the MC14500 to turn up and I can test.....apparently mid next month Sad

[Updated on: Sun, 29 July 2018 00:10]

Report message to a moderator

Re: Mini MC14500 board [message #4970 is a reply to message #4963] Tue, 31 July 2018 16:00 Go to previous messageGo to next message
trick-1 is currently offline  trick-1
Messages: 119
Registered: September 2016
Senior Member
Hi Folks

Well no sooner than I said that it would be some time before the MC14500 turns up guess what.....it was in the mail box that day!

So some debugging was required to find one small error in the connection of the clock circuit to MC14500; resulting in a track cut and a jumper. See attached photo. Will update for any release boards should people be interested. Alternatively if numbers are low I am happy to release with the errata. I have 2 spare boards for any early adopters.


The video is a demo sequence that shows

RESET
IEN 1010, Data = 0
OEN 1011, Data = 0
LD 0001, Data = 1
AND 0011, Data = 1
STO 1000, Data = 1

I think that demos the board working properly. I need to go through and do some more testing but thought I would share.

cheers

Richard
  • Attachment: image1.jpeg
    (Size: 1.92MB, Downloaded 130 times)
  • Attachment: Video.MOV
    (Size: 7.08MB, Downloaded 97 times)

[Updated on: Tue, 31 July 2018 16:11]

Report message to a moderator

Re: Mini MC14500 board [message #5355 is a reply to message #4970] Fri, 19 October 2018 06:31 Go to previous messageGo to next message
b1ackmai1er is currently offline  b1ackmai1er
Messages: 229
Registered: November 2017
Senior Member
Looking forward to seeing first z-machine implementation Smile

Re: Mini MC14500 board [message #5836 is a reply to message #5355] Wed, 16 January 2019 17:53 Go to previous message
trick-1 is currently offline  trick-1
Messages: 119
Registered: September 2016
Senior Member
Hi Folks

Build information and files are now up under Boards | SBC | Mini MC14500

https:// www.retrobrewcomputers.org/doku.php?id=boards:sbc:mini_mc145 00:mini_mc14500

please let me know if any issues/questions etal

[Updated on: Wed, 16 January 2019 18:00]

Report message to a moderator

Previous Topic: Recommended source for WD37C65?
Next Topic: SDC_One - a contemporary computer with a a real, classic CPU


Current Time: Sat Aug 24 10:52:34 PDT 2019

Total time taken to generate the page: 0.01318 seconds