Hi,

Has anybody used the T65 VHDL offered by opencores.org?
Does it have the complete 6502 instruction set?
How true to the original instruction cycle count does this core conform?

TIA!
Ed

No.
Yes (all legal instructions)
Yes (alledgely)

From OpenCores:

Description

Configurable cpu core that supports 6502, 65C02 and 65C816 instruction sets.

A SoC debug system with ROM, RAM and two 16450 UARTs is included in the distribution. It is possible to run the NoICE debugger on this system.

Batch files for runnning XST and Leonardo synthesis can be found in syn/xilinx/run/. Check these scripts to see how to use the included VHDL ROM generators.

Before you can run the scripts you need to compile hex2rom and xrom or download binaries from here. You must also replace one of the hex files in sw/ or change the batch files to use another hex file.


Features

6502 NMOS mode is cycle accurate, including dummy read and writes
Decimal mode is supported

Status

NMOS 6502 mode supports all documented instructions
65C02 and 65C816 modes are incomplete
Complete enough to run EhBASIC

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs