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18 votes
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What happened to the 65832?

In the 1988 Report on the 65c832, Mensch described the 65c832 as a back-burner project with an uncertain timeline: Since WDC is not a gigantic conglomerate, it has limited resources. If all ...
Michael Graf's user avatar
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10 votes
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Asking explanation of 65C02 assembler code

These are the page parts of all absolute addresses within the program. The whole process is described in detail on page 177 of the book (third paragraph). The program is compiled to run at page $21 (...
Raffzahn's user avatar
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9 votes

Asking explanation of 65C02 assembler code

The relocatable routine is assembled to $2100: =2100 112 CMDCODE EQU * Relocation is simplified by the CMDCODE routine only occupying one page and starting at a page boundary, ...
Nick Westgate's user avatar
8 votes

What happened to the 65832?

I suppose you have heard of the draft datasheet of the 65832? https://downloads.reactivemicro.com/Electronics/CPU/W65C832%20CPU%20Datasheet%20v2.0.pdf Apple was the main customer of the 65816 (for ...
Grabul's user avatar
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7 votes

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

65C02 is a CMOS version of 6502 (which was NMOS) chip. Judging from Wikipedia articles on these chips and few of the datasheets I found, it seems like it should work exactly the same way it did on ...
Algimantas's user avatar
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7 votes

Is the W65C02S TTL-compatible?

There's a good discussion about this at the 6502.org forum, where somebody was also in contact with WDC and got a reply from Bill Mensch. Opinions seem to differ a bit but I think this quote from ...
Retrograde's user avatar
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7 votes

Can someone help me port the fat32 library used in the x16 to my homebrew 65c02?

Arguably, it would be easier to port your code to ca65 than the fat32 code from ca65. The ca65 toolset is quite robust. 90+% of that code (at a glance at least) is "just 6502". I don't see ...
Will Hartung's user avatar
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6 votes

Is the W65C02S TTL-compatible?

Is the W65C02S TTL-compatible? TLDR: Yes as compatible as various implementations can be. After all, compatibility means that devices can work within given specs, not that they are the same in all ...
Raffzahn's user avatar
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5 votes

Interrupt pin type on the 6502

The W65C02 data sheet does explain it (p. 9): 3.4 Interrupt Request (IRQB) The Interrupt Request (IRQB) input signal is used to request that an interrupt sequence be initiated. The program ...
dirkt's user avatar
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5 votes
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What are the normal signals on a 65C02 in an Apple IIe?

I've been meaning to get around to this for ages, sorry. Tonight I stumbled across SAMS COMPUTERFACTS for the Apple IIe which I had downloaded from the Internet Archive. Here is the logic chart data ...
Nick Westgate's user avatar
4 votes

What happened to the 65832?

At some point before 1990 the idea seems to have first surfaced as a 'report' about 6502 chronology and future processors might suggest. It includes not only information about the ghostly 6516, but ...
Raffzahn's user avatar
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4 votes
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65C816: Inputs TTL-compatible?

Are old 65C816s TTL compatible? If their Vih is 2.0v, they are certainly TTL-compatible. Was there some kind of change? All WDC chips seem to be verilog-reimplemented, so when they synthesized ...
lvd's user avatar
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3 votes
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Interrupt pin type on the 6502

The interrupt pin is an input.
Justme's user avatar
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1 vote
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Is the W65C02S TTL-compatible?

The short answer is that in the general case, no, the W65C02S is not TTL-compatible. However, you can probably make it work reliably in a TTL system if you know what you're doing, you're careful (...
cjs's user avatar
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1 vote

Is the W65C02S TTL-compatible?

Technically, if this is about the CPU itself being TTL compatible, no it is not compatible, because according to datasheet, it uses standard CMOS level inputs, which are not compatible with TTL level ...
Justme's user avatar
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1 vote

Interrupt pin type on the 6502

An interrupt pin of a CPU will always be an Input. After all, it's whole purpose is to tell the CPU about an interrupt pending. Wouldn't work if it's an output, would it?
Raffzahn's user avatar
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1 vote

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

Who made your 65C02? Was it WDC? If it's WDC, then there are a few pins that should be held high with a 3.3k pull-up resistor. Such as the BE pin which is only on WDC versions. BE (Bus Enable) ...
cbmeeks's user avatar
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