#pc6502 — Public Fediverse posts

Interesting problem with #LT6502 main board, I've got the RAM, ROM, CPU and Glue on now.
I've the minimal glue logic in and I can see it starts EhBASIC and I can even run Mandelbrot.However, it only sends data out when data is coming in. I.e. to see the Mandelbrot being generated I have to hold down a key.....
Glue code is the same as my #PC6502, schematic for the FT245 is the same, so I'm very confused.

Got my first transputer program running from my #PC6502

Very simple code that spits out 0xAA000000 if it’s a 16 bit transputer and 0xAAAA0000 if it’s 32 bit.

Output is -
<< READ =$AA
<< READ =$AA
<< READ =$00
<< READ =$00

Next write something simple to confirm the tool chain I have works.
Then a server program to run on the 6502, so I can then run some Mandelbrot code on the transputer.

Long way to go, but fun

#retrocomputing #transputer #6502

Here it is, and oh boy does it get toasty!
Next I best figure out how to get it doing something, like say..... a Mandlebrot!

#Transputer #PC6502

FINALLY!!!
The #PC6502 is talking to a #transputer !!
I can now write and read to the memory on the TRAM !!!

Colour me very happy!!!

#Retrocomputing

To nights fun with the #PC6502 tower, a Sierpiński triangle.
Didn’t take me quite as long to get running.
This is sped up video, it takes about 2 minutes to plot 2000 random dots.

I woke up at silly o’clock, so I did some work on my #PC6502 computer and scaled the mandlebrot up.
This is now 168x240 (screen is 272x480) and is using the screens rectangle function as I still can’t get a single pixel to plot.
When done it draws a white rectangle around the whole image.

#retrocomputing #mandlebrot

Oddly enough I can’t get a pixel to plot, but I can get a line. So I did the #mandlebrot on my #PC6502 computer.
Had a play with colours and scales until I got a combination I liked.
The image in real life is much more vibrant.
#retrocomputing

Wohooo!!!
Finallly got the display for my #PC6502 system running!!
Currently text and the wrong orientation but graphics is only a hop and a skip away!
#retrocomputing

Wooot today’s haul of chips from someone at work having a clear out of his loft.
12 Inmos T414 #transputer chips and 7 TMS32020 DSP chips
I’m looking forward to connecting these to my #PC6502 stack when the PCBs arrive (couple of weeks time)

Finally after several days, I’ve managed to get the start of display initialisation code in for my #PC6502 stack and I can write and read data to/from the display using SPI (65SPI2).

Console output -

RUN
RA8875 INIT:
CMDWrite>: 0x80 CMD>:0x00
DATAREAD>: 0x40 Data<:0x75

Ready

So the next step is to add in rest of the init code and try to write hellos world on it.

In more positive news for my #PC6502 stack, @shonky ported EhBASIC and the enhanced WozMon to the platform!
EhBASIC is slightly quicker than OSI basic, but the main thing for me is the ability to handle hex for values!

Code and Binary in my repo.

Keycaps arrived for my #PC6502 keyboard.
It works pretty well, I need to figure out a bit more on the controller code, but it’s working.
It sends and receives 5v TTL serial at 115200

Working on the keyboard for the #PC6502 so far it’s sending and receiving characters, not sure what I’ll do with the function keys yet.

Wanted to play around more with Mandlebrot on my 6502 (now running at 14.16MHz CPU clock)
Looks funky with a small font, almost like it has colour.
#PC6502

I got round to setting up the YM262 OPL chip on my #PC6502 computer stack and playing a tune.
I've not figured out why I get the "click" on note off :(
#retrocomputing

Working on the Keyboard and TFT display for my #PC6502 computer.
Still a way to go before I'm ready to order PCBs, but you can see the 4.3" 480x272 screen that will hang down the side of the stack and get a feel for the keyboard.
I'm kinda going simple keys with only the space bar and Enter key being non square shapes.
Also I have a couple of QDSP-2118 displays, one of which will go on the keyboard just because why not.
I've gone with RJ45 connectors, as I have lots of cables.

#retrocomputing

Here is the #pc6502 stack so far.
I’m still working on the AIISlot PCB but so far it looks good.
Thank you to Mr #Rc2014 for the CF card.
I’ve started work on the keyboard interface, I expect it’ll be a couple of weeks before I have any update on that (PCB design, order, assembly, etc)
The red card is an apple II transputer adapter.

I'm trying to decide on how to implement a keyboard for the #PC6502, I have two options. Which should I go for?

The CPLD/TTL way appeals but it means using huge 25 way dtype connectors and a fair bit of assembly language work.

The Microcontroller way means I can use a much smaller (and cheaper) 4 pin connector of some sort and also keeps assembly code work to a minimum (also less impact on CPU speed).

I don't want a PS/2 Keyboard.

I can't decide, please help.

#retrocomputing

A couple of bodge wires and the OPL3 chip works on the same board as the SP0256 speech chip on my #PC6502 computer.
Next I guess I need to make it play some music.
#retrocomputing

Well the #PC6502 Dual SPI board is working a treat!

Here is an image of the logic analyser receiving a count from 0 to 255

And if I put a loop back on, it seems to send back what it sent.

The rev 1.1 #PC6502 CPU board, with 6502 running at 8MHz (16MHz clock /2) ROM, RAM and Console via USB C

#PC6502 Power Supply card.
This will negotiate up to 15W from USB C.
If the DC input is available (9V-26V) then it can provide 50W @ 5V

#PC6502 PCB pictures showing the current state of play.
Here is the full stack.
Top to bottom we have;
* Apple II slot card
* VIA card
* Dual SPI card
* Compact Flash Storage card
* OPL3 and Speech card
* 6502 CPU, RAM, ROM, console card
* power supply (USB upto 15W or DC barrel upto 50W)

#retrocomputing

#PC6502 gets a new board, this is the SP0256 speech synth and OPL3 chip board.
No CPLD code yet, but power ok and no magic smoke escape.
#retrocomputing

More fun with the SP0256 chip being driven by my #PC6502 computer.
#retrocomputing

#PC6502 hooked up to an SP0256 using the VIA board (65c22 based)
Not entirely correct as I’m playing the allophones at a fixed rate and some are longer and some are shorter so it’s not quite the correct words.
But it’s sounding cool
#retrocomputing

#PC6502 power supply now working!
This uses USB-PD to give me 5W to 15W from usb or can run from an external 9-36V DC power source to give me up to 50W of power.
#retrocomputing

VIA being controlled from BASIC on the #PC6502 computer.
LEDs are way too bright because this is a PMOD I made for working with FPGAs.

#PC6502 computer lives!
Now running with a 12MHz oscillator so 6MHz clock speed. USB console working great too!
Also the VIA is working too.
Couple of bodges needed as I forgot that a pin I used for clock input on the CPLD for the previous version could not be an output on this version.
GitHub all updated.
Next up will be the power supply board.
#retrocomputing

Well seems Fusion360 won't open for me any longer, most odd.
So I tried FreeCAD, overall I'm not impressed, but I could at least import the step files for my #PC6502 boards and stack them.
From Bottom to Top
- USBPD/24V DC PSU
- Compact Flash storage
- FM & speech synth sound card
- VIA card
- CPU ROM & RAM