Month: August 2018

Posted on by

Public Git Repositories

I’ve moved my source code control to Github and am starting to make some things public.  At this exact moment in time, only xSBUG is public but more will be appearing in the next few days.

https://github.com/CorshamTech

 

Posted on by

Security Finally Installed

Friday night and most of Saturday our web page was kind of up, kind of down, while the SSL certificate was added and pages adjusted.  At this point I do believe things are back to normal and everything should be working again.

So you can now access the pages as https://www.corshamtech.com and all transfers will be encrypted and secure.  Sorry for being late to get this done but there are a lot of things on my to-do list.

 

Posted on by

SS-50 65C02 Board Experiment

My very first computer was a KIM-1 (bought in 1978, almost exactly 40 years ago) and my first job at Franklin Computer was writing 6502 assembly code, so I’ve been a fan of the 6502 for a long time.

Recently I was toying with the idea of an SS-50 CPU board with a 6502, but then decided a 65C02 would be a better option.  The 6502 started as a copy of the 6800 so it was easy getting it onto the SS-50 bus.

This is the result:

I’m not really planning on this being a product soon, as it was more of an experiment.  Besides the board, I also needed to develop a monitor (CTMON65) to allow the console to do things.  Basic specs:

  • 65C02 running at 2 MHz.
  • RAM from 0000-7FFF.
  • RAM can be enabled in 4K blocks from 8000-EFFF.  Allows positioning RAM around the SS-50 I/O ranges for either a 6800 or 6809.
  • Baud rate generator for 1200, 2400, 4800 and 9600 baud.
  • 28C64, 28C128 or 28C256 EEPROM.  Jumpers select the high order address bits so up to four monitors can be in EEPROM.
  • The regions from E000 to EFFF can be RAM, ROM, or not enabled (I/O for 6809).
  • Includes a software driven single-step function, exactly like the KIM-1 does it.  Monitor functions do all the work.
  • Monitor (CTMON65) supports all the usual stuff, including support for the SD Card System.

The monitor has been going through some re-writes and isn’t ready for doing much.  There are a lot of software projects on my to-do list, this being one of them.

At this point, this isn’t a product, as I don’t think there is much demand.  The 6502 never had a dominant OS except for machine-specific ones, so there is no generic OS I can simply write drivers for and have it work.

Anyway, this was my fun project recently.  I’ll probably have it at VCF MW next month.