I managed to get a 6502 CPU running on the ULX3S and wrote a 16 color indexed display RAM module for it. The CPU also has access to all the buttons and the LEDs, which are counting up the current low byte of display RAM. Its the most complex bit of Verilog I've written so far. I hope to add basic sound support next, and then I'll have made my own little toy console to mess with. #ulx3s #fpga #6502CPU
#6502CPU
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#VolksForth booted today on the #Sorbus Computer (made by SvOlli -> https://xayax.net/sorbus/) #Forth #retrocomputing #6502CPU
RISC architecture may "gonna change everything", m'kay, but do you also see numbers, like me?
Here, two take a Kawasaki KLR 650 which makes it a... 6502.
- https://www.imcdb.org/vehicle_99638-Kawasaki-KLR-650-1987.html
#Hackers #6502cpu #Kawasaki #motorcycle
Visual Transistor-level Simulation of the 6502 CPU
www.visual6502.orgwww.Visual6502.org
"Calypsi" is a collection of compilers and assemblers that run under Windows, Linux and macOS and can generate code for various retro platforms - 6502 and 68000 processors are supported, among others. Although the project is hosted on Github, the source code is not freely available and use of the tools is only permitted for private purposes. Now version 5.10 is available. Changes:
www.amiga-news.deamiga-news.de - Cross-compiler/assembler: Calypsi 5.10
Just arrived today... Ordered this as I am not sure if the one I have is faulty.
Most likely it is my Arduino glue logic code that is faulty and not the #6502CPU. However, just in case I do break, or have broken it, there is no harm having a spare!
Also, there is no such thing as having too many 6502's 
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@cas : slow?
Mwah, after asm hacking (6510) I learned Pascal with an "editor", compiler and linker loaded from multiple cassette tapes (one at a time) on my Commodore 64 (more than 40 years ago).
Later I learned 68HC11 asm which was a nice CPU too, slightly better than 6502 (or 6510). Of course the 68000 was a giant step (considering Zilog Z80 and Intel 8080 via 8086 to 80286 CPU's).
Nice to see that there are still people who love to hack low level stuff. The world will keep needing those who understand "basic" building blocks!
Two versions of a 6502 assembly routine. We have a byte in X. Its bits are denoted %ABCDEF00. We want to get bits %0BCADEF1 in the accumulator. Each version is 23 bytes. The first one doesn't need a look-up table. The second one does but is much faster and doesn't need a temporary variable.
#6502cpu #assembly
; version 1
txa
and #%01100000
sta temp
txa
lsr a
lsr a
lsr a
and #%00010000
ora temp
sta temp
txa
lsr a
and #%00001110
ora temp
ora #%00000001
; version 2
txa
asl a
rol a
rol a
rol a
and #%00000111
tay
txa
lsr a
and #%00001110
ora table,y
...
; look-up table for version 2
table: db $01, $21, $41, $61, $11, $31, $51, $71
Selbstbau neo6502 Schlepptop von WOST auf dem Forth Sommertreff im UpH in Essen
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Cyberspace-1 clock board up and running! Other than solder issue, it just works. The crystal clock source seems to run but not at the right rate. Will need to debug that. See video for show and tell. #cyberspace1 #6502CPU
Time to toggle off the Zodiac project while I wait for a couple missing parts to show up. Moved over to my Cyberspace-1 home brew 6502 project. Remaining parts showed up for that yesterday so had a Zen solder party to get this one ready for bring-up tomorrow. If this works, I can continue design work for the CPU card, memory card and Video/IO card. Loosely based on the HBC-56 homebrew computer by a GitHub user called visrealm. #homebrewcomputer #6502CPU
Finally had some time to get some quality youtube time this evening… https://youtu.be/75jz8UZjrTo?si=vZHYkkSCbHwNOv7Q this is an amazingly well documented and produced video and project. A #6502CPU computer on a #rp2040 all in #assembler. Highly recommend Dave’s video. Open up the opportunities for more #retrocomputing on a budget!
You never forget your first true love.
There are two really cool #raspberrypipico + #6502CPU #8bit computer project I am following closely:
GitHubPicocomputerPicocomputer has 11 repositories available. Follow their code on GitHub.
Sitting here studying the #6502cpu addressing modes, indexed indirect and indirect indexed, to be specific... Deciding to write your own emulator in #C++ really does demand that you know the details intimately! Page wrap-around, or not, and extra cycles for page boundary crossings are all extremely interesting details!
The KIM-1 replica lives!
#kim1 #diyelectronics #6502cpu #retrocomputer #retrocomputing
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@digichelle Nothing to be sad about! I am the same, mostly emulated because who has the space it all? I visit a museum for my "fix" of the real stuff. I think they still have a virtual tour.
Although, I am currently playing with a real #6502CPU on a breadboard with an #Arduino for all the glue logic. Having fun writing some #assembly for it.
The National Museum of ComputingThe National Museum of ComputingHome of the worlds oldest computers
Clock circuit for Ben Eater's 6502 computer kit: complete! This was my first ever experience with building electronics on breadboards and I learned a lot.
A #linux (and #unix) guy with varied interests in the #kernel, #networking and #filesystems, generally #sysadmin stuff, some computer languages, a few earlier technologies #m68k #z80 #6502cpu, and #retrocomputing history including old arcade games (thus #fpga).
Active fan of #openstreetmap and #sunset photos.
#introduction