Hey everyone!

I'm posting on this topic again because... I've been working on my very own NES emulator! Over the past couple of days I've been coding the 6502 instruction set in C, using a lot of pre-compiler macros. Did you know that STA (d),y uses the indirect addressing to *store* a value, not ...

If you want to run a program on boot, then you need to burn it into an EPROM and put it on an expansion card.

If the program is less than 256 bytes, you can put it map it into $CX00 where X is the slot number.
The first few bytes need to be the ID of a disk controller so the ROM will jump to the ...

Has anyone experienced or heard of problems when accessing fast memory slowly? Such as 20-55nS sram being accessed with 500nS /CE?
SRAM means “ static random-access memory.” The key word here is “static,” which means the RAM merely responds to input signal states (low or high), without regard to ...

I have in front of me "Computer Architecture: A Quantitative Approach". This is the standard textbook used in colleges for teaching basic computer architecture written by Hennessey and Patterson, two of the guys who wrote many of the original RISC papers.

If you look at the index at the back of the ...

I find the phrase "Every[one|body] will agree..." is fairly consistently a red flag for a weak argument. It is a weak attempt to take one's opinion and elevate it to the level of a group consensus.


I think he was joking. Since everyone here has some special interest in the 6502, of course we're ...

If I remember correctly, the Commodore Amiga was orginally supposed to be based on the Z8000.
The Z8000 was late to market, so they wound up using the 68000 instead.

Toshi

As far as I know Commodore 900 was designed to have that CPU (Z8000). Amiga (had different name then, can't remember, Lorine ...

In my experience, the most important part of design is to define your end goals.
If you don't have clearly defined end goals, then it becomes impossible to decide whether a particular change is good or bad, because you can't tell whether it brings the design closer to or farther from the end goal ...

You guys are comparing a pipelined processor (6502) with microcoded processors (68000, 8088, etc).
This is like comparing apples and oranges.

Yes, pipelined processors are generally faster-per-clock than microcoded processors because there is no internal state ROM which needs to be sequenced. A ...

Now before this turns into some sort of flame war, if it hasn't already,

Flame war? This has been an academic discussion amongst well respected gentlemen (and ladies?). Everybody will agree here that the 6502 was one of the greatest achievements of the last century, ....

I find the phrase ...

The discrete form of the W65C02S readily operates at 20 MHz, as does the W65C816S. ASIC forms of the 65C02 have run at speeds up to 200 MHz, far beyond what the fastest versions of the 68K family could do.
Standard tests, such as the Sieve, suggest that the 68K does no better in integer addition ...

If I remember correctly, the Commodore Amiga was orginally supposed to be based on the Z8000.
The Z8000 was late to market, so they wound up using the 68000 instead.

Toshi

It's really a variant of the register allocation problem, and compiler writers have been tackling that one for years. It may need heuristics, it may not be optimal, it might have poor worst-case behaviour - but it still might be worth doing!

Cheers
Ed

IMHO this is not a variant of the register ...

Short answer: This is a variant of the halting problem.

Long answer: Imagine you have a program that handles conditions A and B based n external input. Imagine the code that handles A and B are both long and use many variables. Does the compiler allocate zero page memory to A or B or both? If the ...

Your question is too vague to be able to deduce what you're attempting much less offer an useful advice.

Toshi

Another UART you may want to consider is the Zilog Z8530.

It was used on the Apple //gs, so I suspect it would be fairly easy to interface with a 6502/65816 system. It also supports HDLC/SDLC CRC generation in hardware iirc which makes it easy to implement serial LAN protocols such as AppleTalk ...