Hi
I got hold of an eagle schematic for the C64
http://www.baltissen.org/images/c64.png
http://www.baltissen.org/zip/c64.zip
First of all i wonder what board rev matches this schematic? and if there are a high res scan "out there" i could use for initial component placement
Next would part are ABSOLUTE not to be found no where? ie it would be insane to look if it cant be found anyways, but my goal was to do a BOM and board layout
Next, how much use would the work be in general?
Is it at all possible?
Re: Is it at all possible?
Looking at the schematic, the method employed to generate the color and dot clock signals are the same employed on early 326298 boards but the video output connector has separate Luma/chroma signals like board 250407.
Boards 250425 and 250466 used the custom chip 8701 for which I created a substitute.
Other than the MOS 65XX chips made by Commodore, AFAIK, all semiconductors and standard electronic components used in the C64 are still available or possible to replicate. The 8701 was still a problem... until last week.Next would part are ABSOLUTE not to be found no where? ie it would be insane to look if it cant be found anyways, but my goal was to do a BOM and board layout
Ask Schönfeld how much time he needed to create the C64 reloaded... it's really a 250466 with a bit of rework to combine all the ROMs in one chip and all discreet logic ICs turned surface mount.Next, how much use would the work be in general?
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders
Re: Is it at all possible?
With use i mean how much value it would be to others?
My plan is initial to get a BOM made and share that public. I got most of it down only missing the chips
And i also got the schematic in eagle and just need to cross verify everything
Then i will pay a one month license for eagle and do a replica board. With some clever thinking i found that what i have to work with is PCB 326298-01 and Schematic 326106. So pretty much as original as it can be
My plan is initial to get a BOM made and share that public. I got most of it down only missing the chips
And i also got the schematic in eagle and just need to cross verify everything
Then i will pay a one month license for eagle and do a replica board. With some clever thinking i found that what i have to work with is PCB 326298-01 and Schematic 326106. So pretty much as original as it can be
Re: Is it at all possible?
That's a question for a marketing analyst...
Board 326298 is interesting because it is the very first C64 board on the market but it has several drawbacks.With some clever thinking i found that what i have to work with is PCB 326298-01 and Schematic 326106. So pretty much as original as it can be
The first obvious one is that it doesn't provide separate video which really sucks as you can't really get the full image resolution and quality a VIC-II can provide on composite signal.
The second one I can think of is the absence of an adequate RC filter on the CASRAM line which makes it incredibly sensitive with respect to PLA timing.
Many PLA substitutes work perfectly well on boards 250425 and 250466 but not on board 326298 because this filter is missing.
I think board 250466 is the best.
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders
Re: Is it at all possible?
i might expand the work later
for now i just wanted to start somewhere
for now i just wanted to start somewhere
Re: Is it at all possible?
"expand" is the magic word here.
Jens Schönfeld based his C64 Reloaded on board 250466 because it is the version of the Commodore 64 with the fewest number of components, except perhaps for the C64c 250469 which has a larger and incompletely documented PLA.
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders
Re: Is it at all possible?
well i got the schematic down, now i just need a 326298-01 to replicate. it does not even matter what state the board is in. hell all components can be taken out. would even make my job more easy as i would take every single component out anyway so i can use it as a template when doing the tracks in eagle
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