In the context of eBay I mean. What are people's experience with Chinese sellers? I have several NOS 6502s from my childhood. They're good unless they have some sort of time-related failure mode when unpowered and stored properly.
If some random 40 pin DIP with "6502" written on it allows a VIC-20 to boot, does it automatically mean it's a good 6502?
Is there a way to check if each opcode exists and it does what's it supposed to?
6502 test
Moderator: Moderators
-
Gyro Gearloose
- Vic 20 Enthusiast
- Posts: 174
- Joined: Wed Sep 28, 2016 8:26 pm
- Location: Montreal
- Occupation: Drunk
-
chysn
- Vic 20 Scientist
- Posts: 1205
- Joined: Tue Oct 22, 2019 12:36 pm
- Website: http://www.beigemaze.com
- Location: Michigan, USA
- Occupation: Software Dev Manager
Re: 6502 test
I bought some 2716s and 2732s from China via ebay, and I have some pretty good reasons to suspect that they're not exactly what they're marked as. I'm suspicious enough that I'm now actively avoiding buying chips from China.
For most uses, the 65C02 is cheap enough, compatible enough, and easy enough to find that I wouldn't even consider getting an old pull from China.
That said, if a VIC-20 boots up with it, and runs some software, it's probably fine. A test that runs all 151 instructions would be boring to author, but not tricky or super time-consuming.
For most uses, the 65C02 is cheap enough, compatible enough, and easy enough to find that I wouldn't even consider getting an old pull from China.
That said, if a VIC-20 boots up with it, and runs some software, it's probably fine. A test that runs all 151 instructions would be boring to author, but not tricky or super time-consuming.
VIC-20 Projects: wAx Assembler, TRBo: Turtle RescueBot, Helix Colony, Sub Med, Trolley Problem, Dungeon of Dance, ZEPTOPOLIS, MIDI KERNAL, The Archivist, Ed for Prophet-5
WIP: MIDIcast BASIC extension
he/him/his
WIP: MIDIcast BASIC extension
he/him/his
Re: 6502 test
run the lorenz testbench on it... there is a port for the 1541 drive which you could use for that: https://sourceforge.net/p/vice-emu/code ... ite/disks/Is there a way to check if each opcode exists and it does what's it supposed to?
I'm just a Software Guy who has no Idea how the Hardware works. Don't listen to me.
-
Gyro Gearloose
- Vic 20 Enthusiast
- Posts: 174
- Joined: Wed Sep 28, 2016 8:26 pm
- Location: Montreal
- Occupation: Drunk
Re: 6502 test
I'm just a hardware guy who has no idea how software works, but I'll look into it.
I am still trying to repair a faulty Excelerator drive, and ordered some 6502s and 6522s from eBay. That may not have been the cleverest thing to do.
Especially since known good parts are like 10$ each from Mouser.
https://www.mouser.ca/ProductDetail/Wes ... KH5w%3D%3D
Now I realized that the VIC-20 I wanted to use for tests is missing its bottom case, because I think I gave it away or something.
It's a mess over here!
I am still trying to repair a faulty Excelerator drive, and ordered some 6502s and 6522s from eBay. That may not have been the cleverest thing to do.
Especially since known good parts are like 10$ each from Mouser.
https://www.mouser.ca/ProductDetail/Wes ... KH5w%3D%3D
Now I realized that the VIC-20 I wanted to use for tests is missing its bottom case, because I think I gave it away or something.
It's a mess over here!