Questions tagged [65c02]

for questions about the 65c02 microprocessor

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8 votes
2 answers

Asking explanation of 65C02 assembler code

From Gary B. Little's "Apple ProDOS: Advanced Features for Programmers", pages 176 - 188: "Since the ONLINE command handler is not inherently relocatable, all references to internal ...
  • 93
8 votes
5 answers

Is the W65C02S TTL-compatible?

According to the Western Design Center (WDC) W65C02S datasheet, table 6-2 on p.24, Vih on all inputs is VDD x 0.7 = 3.5 V when running the CPU at 5 V VDD. This is somwhat above the level at which it ...
  • 23k
5 votes
0 answers

Transistor-level schematic of 65C02

I am looking for a transistor-level schematic for the 65C02, something like the one for the 6502 created by davidmjc ( I am a teacher planning to give a student ...
  • 1,235
21 votes
3 answers

What happened to the 65832?

In his June 1985 foreword to Programming the 65816 by David Eyes and Ron Lichty, Bill Mensch expresses his hopes for a 6502-derived 32-bit microprocessor: the 65832. WDC is still thriving, but the ‘...
  • 2,120
3 votes
3 answers

Interrupt pin type on the 6502

I have a really basic question. I have to design an 65C02-based personal computer for a school project. I have to draw my own footprint for the 65C02. My question is what type of pin is the IRQB (...
4 votes
1 answer

65C816: Inputs TTL-compatible?

New 65C816 datasheets say that Vih (for the data bus in particular) is 0.8Vdd, i.e. not TTL-compaible. Old data sheets (for example, the one published in Apple IIgs Hardware Reference) say that at 5V ...
15 votes
3 answers

What are the normal signals on a 65C02 in an Apple IIe?

I'm troubleshooting a dead Apple IIe enhanced, and I'm having trouble finding documentation on testing the 65C02 (as opposed to the 6502). Specifically, I've found using a logic probe that pin 6 (...