Building a C4P Replica

Klyball
Posts: 195
Joined: Tue Dec 09, 2014 12:53 am

Re: Building a C4P Replica

Post by Klyball » Thu Aug 30, 2018 12:43 am

Yes these boards will be for cherry mx switches
I believe the 542 keyboards work in reverse of the 600 keyboard were the bit is set when key is pressed
Replica 600 Rev D:8K,CEGMON
Replica 610 Rev B: 24k,MPI B-51 with Custom Data separator D-13
510 on the bench/replica 582 backplane/replica 470a /replica 555/original 570B/2 x Shugart 851
Ongoing : 630 ,620 ,510,542c,custom 590,SA1200,592,594,596,598

Jeff
Posts: 330
Joined: Fri Mar 07, 2014 4:44 am
Location: British Columbia, Canada

Re: Building a C4P Replica

Post by Jeff » Tue Oct 30, 2018 8:12 pm

I am starting with the keyboard. Follow Here:
viewtopic.php?f=3&t=433

/Jeff
Image

Jeff
Posts: 330
Joined: Fri Mar 07, 2014 4:44 am
Location: British Columbia, Canada

Re: Building a C4P Replica

Post by Jeff » Sat Mar 30, 2019 6:27 pm

Hi Guys,

I need some advice. It's time for me to order a bunch of IC's for the boards in my C4P Replica. Many chips are designated non-LS in the Sams documentation. eg 7474 or 7417 or 7400 instead of 74LS74 and 74LS17 and 74LS00. I know LS means "low-power, schottky". What is the difference? Should I substitute LS parts? or order non-LS parts?

Please advise.
/Jeff
Image

Klyball
Posts: 195
Joined: Tue Dec 09, 2014 12:53 am

Re: Building a C4P Replica

Post by Klyball » Sat Mar 30, 2019 11:39 pm

I have use ls parts in all boards and have not noticed any problems, you wont find non ls parts as easy.
Replica 600 Rev D:8K,CEGMON
Replica 610 Rev B: 24k,MPI B-51 with Custom Data separator D-13
510 on the bench/replica 582 backplane/replica 470a /replica 555/original 570B/2 x Shugart 851
Ongoing : 630 ,620 ,510,542c,custom 590,SA1200,592,594,596,598

Jeff
Posts: 330
Joined: Fri Mar 07, 2014 4:44 am
Location: British Columbia, Canada

Re: Building a C4P Replica

Post by Jeff » Sun Mar 31, 2019 4:19 am

MK14HAK wrote:
Tue Aug 28, 2018 9:58 am
Is the Cherry MX key the same footprint as the original OSI key. ie do they fit the original 600 and UK101 board ? :?
Sadly, no. The MX switches have different solder masks, and alignment holes.
Image

dave
Site Admin
Posts: 559
Joined: Tue Sep 09, 2008 5:24 am

Re: Building a C4P Replica

Post by dave » Sun Mar 31, 2019 3:39 pm

Jeff wrote:
Sat Mar 30, 2019 6:27 pm
Many chips are designated non-LS in the Sams documentation. eg 7474 or 7417 or 7400 instead of 74LS74 and 74LS17 and 74LS00. I know LS means "low-power, schottky". What is the difference? Should I substitute LS parts? or order non-LS parts?
The LS parts will almost always be a good replacement for the originals. They have similar propagation times, the same voltage thresholds, and lower power requirements, so your machine will run a little less hot.

Dave

Jeff
Posts: 330
Joined: Fri Mar 07, 2014 4:44 am
Location: British Columbia, Canada

Re: Building a C4P Replica

Post by Jeff » Sun Mar 31, 2019 4:04 pm

Thanks Grant and Dave.

/Jeff
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Mark
Posts: 50
Joined: Tue Sep 16, 2008 6:04 am
Contact:

Re: Building a C4P Replica

Post by Mark » Tue Apr 02, 2019 1:21 am

A bit late, but...

TTL LS works as a replacement for TTL especially if all chips are LS. However TTL can source & sink 2x as much current as LS series, so for things like bus drivers in a loaded C8P, you may be better off with TTL. LS can't drive as many TTL gates when mixing families.

Here is an old Nuts & Volts article describing the different families, and some more detail can be found in ON semiconductors description of TTL & TTL LS families. Generally I use whatever I can find in my parts box (mostly 'LS).
-Mark

Jeff
Posts: 330
Joined: Fri Mar 07, 2014 4:44 am
Location: British Columbia, Canada

Re: Building a C4P Replica

Post by Jeff » Tue Apr 02, 2019 3:16 am

Good Info!

Thanks, Mark

/J
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Jeff
Posts: 330
Joined: Fri Mar 07, 2014 4:44 am
Location: British Columbia, Canada

Re: Building a C4P Replica

Post by Jeff » Tue Apr 09, 2019 1:40 am

Some of my parts arrived, so I built up the 582 backplane board.
582 Top.png
582 Top.png (617.19 KiB) Viewed 1483 times
582 Bottom.png
582 Bottom.png (598.31 KiB) Viewed 1483 times
/Jeff
Image

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