6502.org

My first microprocessor experience was with a SYM-1 in the 'olden' days.
I spent many hours on one and have a fairly large soft spot for them.
A while back I decided to build a new board loosely based on the SYM-1 as a tribute to my old friend.
With help from this site these are my results.

System
- 65C02 at 2 Mhz
- 64K RAM with holes for IO and 8K monitor in EPROM
- two 65C22 VIAs with all IO lines brought out to header pins
- 65C51 UART
- 8K monitor program in EPROM based on the SYM SUPERMON
- I2C interface for mass storage on serial EEPROMs (24CS512)
- socket for USB-serial module for interface to PC if desired
- socket for 8K EPROM for user program
- onboard ASCII dumb terminal drives a 10" VGA monitor (PIC based from VT100 work by Graham and Hansel)
- USB keyboard (can be wireless)
- 5v/12v DC boost converter to power monitor
- can boot images of BASIC, ASSEMBLER (RAE) and FORTH from serial EEPROM
- all thru hole components for easier soldering

The serial EEPROM boards are used as pseudo-disks for saving BASIC programs, RAE programs and FORTH screens.
They are stackable so you can have several available at any time.

The I2C connector will also accept one of the RTC modules that are available online.

Maybe this will bring back some pleasant memories for others. Enjoy.

Very nice!

Interesting to see all the options for memory and eeprom including the I2C. I had dragged out my SYM-1 and KTM-3/80 about a year or so ago and interfaced to an IDE-CF card interface as described in the posts about symbiosys from 2012-2013. It worked nicely but the lure of more RAM and higher speeds had me put the SYM away and build some of plasmo's boards. I would be interested in more details about the board design and interface options if you have links. Thanks for sharing.

Yes, good eye. I'm going through a steampunk phase.
It does make for a nice handle though.

You might get a kick out of my keyboard.

I don't have any links sorry, but I can try and answer any questions.

The CF card interface sounds nice, I had thought about that or SD but it seemed to be a little out of my comfort zone.

Oh. To my surprise, people have been talking about the Symbiosys/6522IDE code...

After working with Zen on the Symbiosys project, I built a VIC20 expansion board with dual 6522s, one of which controlled a CF Card with the 8-bit ATA/IDE. I've just put code online at: https://notabug.org/vk2cjb/VIC20-6522IDE

The project also references a later project from that that I called Abiosys, which was a 6502 SD Card controller/DOS, with a link to its repository.