VIC-20 Based 6502C/6522C Test Bed
Posted: Sat Jun 13, 2020 7:03 pm
I picked up a couple VIC-20 "cores" that mean they are the main board with all the socketed ICs removed.
That includes the 6502 and 6522 chips.
I ordered from Mouser the 65C02N and the 6522N replacement ICs and have been told in my newbie post that they are issues with the 65C02S.
Also it appears the pin-compatibility isn't 100%, and the VIC-20 basic crashes.
That's okay because my purpose isn't to bring up a VIC-20 but to "play around" with some ideas with emulating the 6502 devices using an Arduino Mega.
There is an existing project, a Fluke 9010A replacement project, that uses the Mega - see Paul Swan github and posts:
http://www.zzzaccaria.com/arcade/ArduinoMegaICT.htm
https://github.com/prswan/arduino-mega-ict
Attached is a photo of his Mega In-Circuit Tester Shield connected to ribbon cables.
And also posted is a 3D image of the interface card that was designed to plug into the VIC-20 Expansion Port.
I am going to provide an external clock source based on the "Ben Eater" 555-timer based clock he uses with his 65C02 project.
That will have to jumpered on the VIC-20 main board.
Another jumper will have to go from Kernal ROM chip select pin on a 74138 on the main board.
I moved to the hardware thread to provide updates and gather any feedback.
That includes the 6502 and 6522 chips.
I ordered from Mouser the 65C02N and the 6522N replacement ICs and have been told in my newbie post that they are issues with the 65C02S.
Also it appears the pin-compatibility isn't 100%, and the VIC-20 basic crashes.
That's okay because my purpose isn't to bring up a VIC-20 but to "play around" with some ideas with emulating the 6502 devices using an Arduino Mega.
There is an existing project, a Fluke 9010A replacement project, that uses the Mega - see Paul Swan github and posts:
http://www.zzzaccaria.com/arcade/ArduinoMegaICT.htm
https://github.com/prswan/arduino-mega-ict
Attached is a photo of his Mega In-Circuit Tester Shield connected to ribbon cables.
And also posted is a 3D image of the interface card that was designed to plug into the VIC-20 Expansion Port.
I am going to provide an external clock source based on the "Ben Eater" 555-timer based clock he uses with his 65C02 project.
That will have to jumpered on the VIC-20 main board.
Another jumper will have to go from Kernal ROM chip select pin on a 74138 on the main board.
I moved to the hardware thread to provide updates and gather any feedback.
There may be others; but again, there are no actual bugs with the 65c02.