Hi,

I modified pico-6502 to emulate Apple1 (Replica1).
It worked with original binary of Wozmon, krusader, and 8K basic, which located at $E000-$FFFF.

I forked noneya's dev branch and create new branch.
https://github.com/kuwatay/pico-6502-apple1/tree/apple1

Thank you for your useful code ...

jfoucher > I forked the repo and will sync my changes tomorrow. Let me know if you would be interested in pull request back to your repo ?

I'm curious if Fake6502 is open source, as well as the work you've done with 6502emu.c, etc?

Thanks

Sorry for not responding earlier. As far as I can tell ...

Actually I don't think you'd even need the BIT instruction, would you? LDA sets the negative flag so you could just do
Not that it changes anything compared to using BIT...

Very nice Bill, I will be studying your code closely. I actually tried not setting the track/sector registers, as that saves around 9 bytes, but then I could not read from the card. I'll have to try again, because maybe something else was wrong while I was testing this.

Here is the new post: viewtopic.php?f=2&t=7559

Hi,

I recently got a CompactFlash card working on my Planck computer, and for some reason, I've been trying to create the smallest possible bootstrap code, that will copy code and data from the CF card into RAM and jump to it.

I'm down to 81 bytes (excluding reset vectors) and I thought it would ...

So this is as far as I managed to get:


reset:
cf_init:
jsr cf_wait
lda #$E0
sta CF_ADDRESS + 6
lda #$1
sta CF_ADDRESS + 1
inc
sta io_buffer_ptr + 1 ; store 2 in high byte of pointer
stz io_buffer_ptr ; store 0 in low byte of pointer
lda #$EF
sta CF_ADDRESS + 7
jsr cf_wait
set_lba ...

Oh very nice, thank you!

I believe you can read CF into RAM with 32 bytes of ROM
Haha, ok, challenge accepted! I'll give that a try first of all and let you know how it goes!

A 22V10 would probably make a good small ROM - it has lots of product terms.
Oh interesting on the 22V10, I have quite a few of those. I'll see ...

I have recently managed to read data from a CompactFlash card, and I wanted to try using a very small boot rom just for the challenge I guess, to see how low I go go and still be able to load everything into RAM from the CF card. I managed to get it down to about 200 bytes, which I thought was nice ...

Hi, I'm looking for a very small parallel EEPROM that is available to buy right now. 256 bytes would be sufficient. Do they exist? i assume they existed in the past, but can they still be found now, and if so where should I start looking? Mouser et all do not have any parallel EEPROMS with a ...

I read that post and wondered if some of the later steps where the generated assembly is refined could be applied to hand-written assembly code. I have not been able to find the source code for the compiler though, and most of the algorithms in the post seem way above my head.

Anyone know if the ...

Thank you floobydust for the code listing. it helped me a great deal when trying different things. I still had some trouble getting reliable reads from the CF card, even after trying probably everything that was offered here.
I then realized that plasmo's comment about signal integrity was probably ...

Final (I hope) update. I finally managed to read random binary data on the CF card by changing my reading code to the code below:

cf_read:
phy
ldy #0
@loop:
lda CF_ADDRESS
sta (io_buffer_ptr), y
iny
bne @loop
inc io_buffer_ptr + 1
jsr cf_wait
@loop2:
lda CF_ADDRESS
sta (io_buffer_ptr), y ...

So, what I ended up doing was not trying to read a FAT or other filesystem, and instead just use the block storage that Taliforth expects, since this is what I am using on my machine. After a bit a fiddling, it turns out that reading and writing blocks works perfectly fine there. (I also changed the ...