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
Building a C4P Replica
-
- Posts: 233
- Joined: Tue Dec 09, 2014 12:53 am
Re: Building a C4P Replica
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
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
-
- Posts: 370
- Joined: Fri Mar 07, 2014 4:44 am
- Location: British Columbia, Canada
-
- Posts: 370
- Joined: Fri Mar 07, 2014 4:44 am
- Location: British Columbia, Canada
Re: Building a C4P Replica
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
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
-
- Posts: 233
- Joined: Tue Dec 09, 2014 12:53 am
Re: Building a C4P Replica
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
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
-
- Posts: 370
- Joined: Fri Mar 07, 2014 4:44 am
- Location: British Columbia, Canada
-
- Site Admin
- Posts: 717
- Joined: Tue Sep 09, 2008 5:24 am
Re: Building a C4P Replica
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
-
- Posts: 370
- Joined: Fri Mar 07, 2014 4:44 am
- Location: British Columbia, Canada
Re: Building a C4P Replica
Thanks Grant and Dave.
/Jeff
/Jeff
-
- Posts: 297
- Joined: Tue Sep 16, 2008 6:04 am
- Location: Madison, WI
- Contact:
Re: Building a C4P Replica
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
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
-
- Posts: 370
- Joined: Fri Mar 07, 2014 4:44 am
- Location: British Columbia, Canada
Re: Building a C4P Replica
Good Info!
Thanks, Mark
/J
Thanks, Mark
/J
-
- Posts: 370
- Joined: Fri Mar 07, 2014 4:44 am
- Location: British Columbia, Canada
Re: Building a C4P Replica
Some of my parts arrived, so I built up the 582 backplane board.
/Jeff
/Jeff