I've redone my schematic in KiCAD. I've also simplified the glue logic to the best of my ability, primarily by ignoring A7 and A6 in the address decode logic when it comes to the I/O devices, and using a series of OR gates to select between either the built-in I/O on page $80 or any expansion I/O on ...

- BASIC (might be tinybasic, might be EhBASIC, might be custom, who knows!)

EhBASIC won't fit into 8K but there are versions of MS BASIC that will.
I figured that out pretty quickly after looking up EhBASIC. It needs 10K of memory to hold the interpreter. While that means it could potentially ...

Alright, I think I've got somewhat of a schematic ready. I wouldn't say it's complete though, as it probably lacks the circuitry to make sure everything can work together properly in terms of timing (and by probably I mean definitely). It also lacks the priority interrupt circuitry because I forgot ...

The 6502 version of the Cupid Shuffle?? Or do I have the wrong song/dance?

Good plan on following BDD's guide.... however, if you're planning on using one channel of the 28L92 as a console, you might want to consider using a FTDI USB-UART adapter. This will simplify getting a basic console running on any modern machine which, rarely has anything like an older style RS-232 ...

I'm sure you mean ms, not ns. (1ms is 1,000,000ns.) If you have an odd clock frequency, what you can do is have the ISR add or subtract a tick every so many, in the RAM variables. This also works for correcting for an oscillator that's a little off, like if you were able to compute the perfect ...

In that case, I'm wondering what the hell I'm supposed to do with the 71.728 I got when I solved for n, putting 10ns in for T (the T1 period) and putting in 7.3728 MHz in for p (phi2). Am I supposed to just round down the phi2 to 7 MHz? If so I would get a 68 as a result instead, which makes more ...

Alright.

(Also, quick question for Garth - what is the n in the T1 period equation on your website?)

Well, replacing a 65(C)51 with a SC28L92 should be fairly trivial from a hardware side. I replaced a 6551 with a SCC2691 (earlier NXP/Philips UART) which has the same basic hardware differences. Software is more involved, but you can easily start with my BIOS that supports the SCC2691... some ...

The full details, schematic, PCB layout, etc. are all on my GitHub repository.

In short, there are two 74HC573 octal latches. These form the 8-bit data I/O latch for the upper 8-bits of the 16-bit data path to/from the Compact Flash card. The third chip is an Atmel ATF16V8 PLD. This is the single ...

What parts are you using? I can just barely see the logos on the 3 smaller chips, but nothing else.

A bunch of useful advice. I'll look into implementing an IDE interface for CF cards, since I want there to be some options for storage.
If you don’t want to re-invent the wheel, you can just use mine, which is both here on the forum and my GitHub page.

http://forum.6502.org/viewtopic.php?f=4&t ...

- Alarm Clock: No RTC, impossible
Au contraire, mon ami! You said you'll have a 65c22. Use its T1 timer to produce an interrupt every 10ms to update the time and date bytes in memory, and if there's an alarm pending, compare to see if you've reached its time yet. I've been doing it for three ...

Many languages will fit into 8k of ROM. To name a few: Forth, Tiny Pascal, VTL (Very Tiny Language), LISP, some smaller advanced Basics, and even a trimmed down version of Applesoft with all its fixes.

Also a lot of common subroutines can be stored in ROM and save a lot of space in RAM, such as ...

A bunch of useful advice. I'll look into implementing an IDE interface for CF cards, since I want there to be some options for storage.