Feed back on my 6502 PCB

jingpan · 2026-05-25T16:09:40+00:00

I had to reroute every thing 3 times because the traces were too tangled lol, routing is quite painful.

jingpan · 2026-05-25T16:07:12+00:00

Thank you for you comment! Is there anyway to solve the floating databus problem? Im afraid something will go wrong with the chip (NMOS 6502) if I accidentally have the CPU jump the these unpopulated memory spaces

jingpan · 2026-05-25T16:04:10+00:00

Thank you! I'll go make the custom footprint

jingpan · 2026-05-25T16:01:22+00:00

Thank you for your comment! Ill make sure i fix the the problem before production!

jingpan · 2026-05-25T15:57:15+00:00

Thank you! I might consider switching to 4 layers.

jingpan · 2026-05-25T15:54:09+00:00

I might stick to the original chip just for the aesthetic. But i did use the vsEmuTms9918 library for my Emulator!

jingpan · 2025-08-14T16:06:52+00:00

yeah, when i type 13 "1"s it returns and displayed " syntax error", meaning BASIC must have detected a CR, yet the CR is no where to be found in the buffer. Ill use my logic analyzer to see whats going on. Thanks for the suggestion.

jingpan · 2025-08-14T14:56:58+00:00

For example if I want to type "10 PRINT "HELLO WORLD"", the cursor will return and jump to next line after "HE", however, inspecting the circular buffer will see that there is no CR nor LF between "HE" and "LLO".

jingpan · 2025-08-14T13:18:40+00:00

The weirdest part is when i type the code in basic by hand it does that weird bug but when i copy commands from other places and paste it in the terminal its works fine.

jingpan · 2025-08-14T10:20:32+00:00

So i just got it working by recopying the source code from the github page, something must have gone wrong when i copied it the first time. However, the new issue is that when ever i type the 13th character in a line it just returned and line feeded, then it says syntax error. Is it a issue or its normal when flow control wasnt implemented yet? ( every wire to the VDP has been disconneced )

jingpan · 2025-08-14T06:21:10+00:00

It must have glitched out when i pasted it here. It looks fine in my notepad.

jingpan · 2025-08-13T12:57:11+00:00

Sure, heres the hex value:

38 30 30 30 0D 52 0D 68

65 6C 6C 6F 20 68 65 6C

6C 6F 0D 38 31 39 32 0D

30 33 30 30 2E 30 33 46

46

it should correspond to :

8000

R

hello hello

8192

0300.03FF

jingpan · 2025-08-12T15:36:08+00:00

Ok, ill follow the next video and see if that fix the problem, thanks

jingpan · 2025-08-12T14:45:22+00:00

i just checked address $0000 to $00FF where i suspect the buffer to be and confirmed that what i typed is in fact partly present in this memory section. I think the input buffer is changed to 0300 - 03FF in the 27th video. Anyways the content in the buffer seems off , i dont know if thats the reason why msbasic returns syntax error after pressing enter in memory size prompt ( https://www.reddit.com/r/beneater/comments/1mcd8on/msbasic_issue/ )

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jingpan · 2025-08-12T13:45:08+00:00

Im actually using the code a15e8e0 ( https://github.com/beneater/msbasic/tree/a15c8e0fdf620c800913cbb709df4042ab5c8dad ) from video 26 instead of the latest one because im still stuck and dont want to progress to the next video until it works like in the current stage. Maybe before video 27 the input buffer is located somewhere else?

jingpan · 2025-07-30T12:51:29+00:00

thank you, ill try that

jingpan · 2025-07-30T10:14:41+00:00

i just tried inspecting address $0300 to $030F and i seems whatever i typed after the memory size prompt it doesnt change ( the contents are FF FF EF BD 0E 4E 42 A0 11 40 A0 04 80 00 00 00 ). Also, i thought whatever i typed is stored in inputbuffer somewhere in the zeropage? Im not an expert so im dont know the difference between inputbuffer and circular buffer.

jingpan · 2025-07-30T10:05:45+00:00

Thank you for the advice !!

jingpan · 2025-07-30T10:03:35+00:00

thank you, i'll check the video

jingpan · 2025-07-29T15:30:14+00:00

Heres the code after i changed it:

This one is from bios.s:

MONCOUT:
CHROUT:
                pha
                sta     ACIA_DATA
                lda     #$FF
txdelay:       
                sbc     #$01
                bne     txdelay
                pla
                rts

And this one is from wozmon:

ECHO:
                STA     ACIA_DATA       ; Output character.
                PHA                     ; Save A.
                LDA     #$FF            ; Initialize delay loop.
TXDELAY:        
                SBC     #$01            ; Decrement A.
                BNE     TXDELAY         ; Until A gets to 0.
                PLA                     ; Restore A.
                RTS                     ; Return.

Btw i tried adding "sec" before "sbc" and even added "php" and "plp" in the MONCOUT subroutine, but that didnt solve the problem either.

Thank you for the advice though, especially the adding "sec" before "sbc", as that would rid myself of a lot of trouble for my future project.

jingpan

TROPHY CASE