I've been thinking for some time how useful it would be if someone with more smarts than I would develop a Generic Universal Serial Device (GUSD). Such a device could be configured to control just about anything.
The core would be a 65C02S with 32k of RAM. By using only 32K instead of 64k, you avoid bank-switching. The 65C02S is still being made and is relatively cheap while making it accessible to CBM hackers who are already familiar with 6502 coding.
I'm thinking it would need a CBM serial bus interface through a 65C22S. A second 65C22S would communicate with the peripheral hardware. Why not use 6526s? Because the 65C22S is still being manufactured.
32k of programmable-in-place EEPROM or flash memory. This is for the Customizable Peripheral Operating System (CPOS).
The CPOS should contain generic serial bus communication routines that let it talk, listen, and generate an ATN signal. It should recognize its (programmable) unit number and secondary addresses. This code would be identical for EVERY peripheral, making updates and version changes easy.
It could even hold a custom version of JiffyDOS.
A well-structured generic code lookup table in flash memory would allow it to be easily reprogrammed for specific applications. This table would define what signals to generate when secondary addresses or data are received.
It should also be possible (and allowed) to download and execute 6502 code in peripheral RAM.
Physically, header pins would allow for easy connection to just about any hardware you wished to connect.
Think plotters, relays, robots, blinkenlights, just about anything.
Now, how cool an idea is this? :D
I've thought about this, like all the other projects I'll never do :-)
The problem I always come to is that in the end it's going to be big.
I much prefer the fpga route, although it's harder in some ways, it opens up alot more possiblities.
Like making 1571/1581 clones.
I appreciate what FPGAs and their ilk can do, but they make things less flexible. I'm also interested in period-possible mods, so an EEPROM would be my first choice (though to be technically correct, you'd have to use just an EPROM).
Quote from: airshipI appreciate what FPGAs and their ilk can do, but they make things less flexible.
what flexibility do you want that an fpga can't achieve?
Can't use a standard EPROM programmer, mostly.
Quote from: airshipCan't use a standard EPROM programmer, mostly.
:D
Thanks for my daily smile.
Actually, my main gripe is just wanting to stay as 80's retro as possible, while making maybe a small concession for convenience sake. But I'll take it any way you want to build it! :)
I think your requirements list just described a standard commodore Vic20/64 or 128 :-)
hehehehe
Mark
It's more like some of the simple single board computer designs, with the addition of having the hardware and software for IEC serial communication. You wouldn't need all the other stuff a CBM computer has.
This (http://www.starting-point-systems.com/index.html) is similar in concept to what I had in mind, but it's modern components and USB for Windows.
(http://www.starting-point-systems.com/images/pict0690hr.jpg)