Plan C | Testing a Few DIY PLA Options (A Bit More Scientifically) @Plan-C | Uploaded September 2019 | Updated October 2024, 24 seconds ago.
I hooked-up a 74LS279 Latch circuit to my C64 test rig to test some DIY PLA solutions. The circuit tests for glitches in the PLA by means of a set/reset latch. I got the idea from MindFlareRetro's video below. I tested 45ns OTP ROMs with and without filters designed by Ray Carlsen, a supposed '906B' chip from eBay (supposed to be the only true drop-in EPROM - if you can find a real one), a couple of pre-programmed PLS100N's (the chip Commodore copied) and a known glitchy MOS PLA for reference. For the record, the eBay vendor that I bought the PLS100Ns from was very professional and issued my with a replacement without issues. He couldn't have been more helpful.
The chips tested were:
1) Atmel AT27C512R4RU - OTP Chip - Just CASRAM capacitor
2) Same Chip with a DIY filter designed by Ray Carlsen: personalpages.tds.net/%7Ercarlsen/cbm/c64/eprompla/readpla.jpg
3) eBay M27C512-90B6 - (no filtering)
4) Genuine but glitchy MOS PLA
5) eBay PLS100N
iNSPIRATION:
Mindflareretro's video is here: The PLAin Truth About The C64 PLA youtube.com/watch?v=ofg33zk9uCA
Ray Carlsen's pages are here:
personalpages.tds.net/%7Ercarlsen/cbm
GadgetUK164's Video which started me off here:
youtube.com/watch?v=sT4OBNvboJ0
ps I recently got a copyright strike from Youtube for using, of all things, circus music! I have taken down two other videos as a precaution:
C64 Flakey PLA Fix &
C64 Re-brick reloaded
If I can find them, I will re-upload with no circus music!
Good luck All
Music is:
––––––––––––––––––––––––––––––
Track: Affect — Vishmak [Audio Library Release]
Music provided by Audio Library Plus
Watch: youtu.be/5uh7qw3NPWA
Free Download / Stream: alplus.io/AffectVishmak
––––––––––––––––––––––––––––––
🎵 Track Info:
Title: Affect by Vishmak
Genre and Mood: Dance & Electronic + Dramatic
License: Royalty free music for YouTube, Facebook and Instagram videos giving the appropriate credit.
———
I hooked-up a 74LS279 Latch circuit to my C64 test rig to test some DIY PLA solutions. The circuit tests for glitches in the PLA by means of a set/reset latch. I got the idea from MindFlareRetro's video below. I tested 45ns OTP ROMs with and without filters designed by Ray Carlsen, a supposed '906B' chip from eBay (supposed to be the only true drop-in EPROM - if you can find a real one), a couple of pre-programmed PLS100N's (the chip Commodore copied) and a known glitchy MOS PLA for reference. For the record, the eBay vendor that I bought the PLS100Ns from was very professional and issued my with a replacement without issues. He couldn't have been more helpful.
The chips tested were:
1) Atmel AT27C512R4RU - OTP Chip - Just CASRAM capacitor
2) Same Chip with a DIY filter designed by Ray Carlsen: personalpages.tds.net/%7Ercarlsen/cbm/c64/eprompla/readpla.jpg
3) eBay M27C512-90B6 - (no filtering)
4) Genuine but glitchy MOS PLA
5) eBay PLS100N
iNSPIRATION:
Mindflareretro's video is here: The PLAin Truth About The C64 PLA youtube.com/watch?v=ofg33zk9uCA
Ray Carlsen's pages are here:
personalpages.tds.net/%7Ercarlsen/cbm
GadgetUK164's Video which started me off here:
youtube.com/watch?v=sT4OBNvboJ0
ps I recently got a copyright strike from Youtube for using, of all things, circus music! I have taken down two other videos as a precaution:
C64 Flakey PLA Fix &
C64 Re-brick reloaded
If I can find them, I will re-upload with no circus music!
Good luck All
Music is:
––––––––––––––––––––––––––––––
Track: Affect — Vishmak [Audio Library Release]
Music provided by Audio Library Plus
Watch: youtu.be/5uh7qw3NPWA
Free Download / Stream: alplus.io/AffectVishmak
––––––––––––––––––––––––––––––
🎵 Track Info:
Title: Affect by Vishmak
Genre and Mood: Dance & Electronic + Dramatic
License: Royalty free music for YouTube, Facebook and Instagram videos giving the appropriate credit.
———
