Bad PLA chips (MOS 906114-01) are a super common problem for the "breadbin" Commodore 64 machines. There are replacements around but they aren't that cheap. How about one you can build yourself at home for under $3?
The GAL-PLA has been tested on longboard PCB 326298, 250407, 250425 and the SX64 with no compatibility issues or modifications required. Tested with Super Zaxxon, 1541 Ultimate II and Easy Flash 3 with no issues on both NTSC and PAL machines.
0:00 - GAL-PLA Overview
10:57 - Testing the GAL-PLA with Super Zaxxon
13:45 - How to build your own PLA
25:43 - Cost breakdown of the GAL-PLA replacement
--- Video Links
** GAL-PLA Website by Daniël Mantione: (All of the information and files to build your own) **
www.freepascal.org/~daniel/c64...
The "PLAin" Truth About the Commodore 64 PLA (and why MOS PLA chips fail so often)
• #10 'The PLAin Truth A...
More information on the PLA including timing requirements:
ftp://ftp.zimmers.net/pub/cbm/c64/firmware/C64_PLA_Dissected.pdf
Super Zaxxon Cart provided by Geek With Social Skills:
/ geekwithsocialskills
--- Parts for this project
PCBWay to the GAL-PLA project:
www.pcbway.com/project/sharep...
TL866-II Mini Pro Programmer:
www.aliexpress.com/item/40000...
Lattice GAL20V8 (Qty 10):
www.aliexpress.com/item/33023...
PIN headers:
www.aliexpress.com/item/32692...
24 pin narrow sockets:
www.aliexpress.com/item/32950...
--- Tools
Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/s.nl/it.A/id.16...
Jonard Tools EX-2 Chip Extractor:
amzn.to/2VazxDS
www.jonard.com/Products/EX-2-...
Wiha Chip Lifter:
amzn.to/3a9ftWw
www.wihatools.com/precision-c...
O-Ring Pick Set: (I use these to lift chips off boards)
amzn.to/3a9x54J
Elenco Electronics LP-560 Logic Probe:
amzn.to/2VrT5lW
Hakko FR301 Desoldering Iron:
amzn.to/2ye6xC0
Rigol DS1054Z Four Channel Oscilloscope:
www.rigolna.com/products/digi...
Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
amzn.to/3adRbuy
TL866II Plus Chip Tester and EPROM programmer: (The MiniPro)
amzn.to/2wG4tlP
www.aliexpress.com/item/33000...
TS100 Soldering Iron:
amzn.to/2K36dJ5
www.ebay.com/itm/TS100-65W-MI...
EEVBlog 121GW Multimeter:
www.eevblog.com/product/121gw/
DSLogic Basic Logic Analyzer:
amzn.to/2RDSDQw
www.ebay.com/itm/USB-Logic-DS...
Magnetic Screw Holder:
amzn.to/3b8LOhG
www.harborfreight.com/4-inch-...
Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
www.ebay.com/itm/14-16-18-20-...
RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
www.retrotink.com/
Plato (Clone) Side Cutters: (order five)
www.ebay.com/itm/1-2-5-10PCS-...
Heat Sinks:
www.aliexpress.com/item/32537...
Little squeezy bottles: (available elsewhere too)
amzn.to/3b8LOOI
--- Links
My GitHub repository:
github.com/misterblack1?tab=r...
Commodore Computer Club / Vancouver, WA - Portland, OR - PDX Commodore Users Group
www.commodorecomputerclub.com/
--- C64 Stuff
JaffyDOS:
blog.worldofjani.com/?p=3544
C64 Test Harness I use:
• Building a Commodore 6...
C64 Homebrew cartridge PCB: (used for the DeadTest / Diag Cart I use)
www.ebay.com/itm/Commodore-64...
EasyFlash 3 Multi-Cart:
store.go4retro.com/easyflash-3/
--- Instructional videos
My video on damage-free chip removal:
• How to remove chips wi...
--- Music
Intro music by:
Nathan Divino
@itsnathandivino
Outro Music:
Abyss by | e s c p | escp-music.bandcamp.com
Music promoted by www.free-stock-music.com
Attribution 4.0 International (CC BY 4.0)
creativecommons.org/licenses/...
--- Image Credits
TI99 Image Credit:
By Rama & Musée Bolo - Own work, CC BY-SA 2.0 fr
commons.wikimedia.org/w/index...