On Monday 07 May 2012, you wrote: > Hi, > > On 2012-05-07 15:42, Per Olofsson wrote: > > You can find more images of a previously sold unit here: > > http://jpegbay.com/gallery/001326274-5.html > > > > Looks like a devkit to me, with RS-232 ports for uploading ROM images. > > I agree. > > The theory that is it a RAM-based cartridge devkit/system suited for > game development is backed up by the fact that they did a lot of work > exposing the *both* joystick ports and keyboard on the front plate. > > It seems a little unlogical to expose especially the joystick ports if > it was a "just" RS-232 communications server... > > > It appears to me that the system never has had any proper back-plate. > This means that all ports of the C64 and the prototype board was exposed > on the back. > > The Textool ZIF-socket on the prototype board seems to have had an > important function as it is directly accessible on the back of the system. > Something that indicates that it is to be used frequently. > > http://jpegbay.com/gallery/001326274-15.html#15 > > From the location of the Textool ZIF-socket another theory could be > that the system is a EPROM burner ? then but why have joyports exposed > on the front ? > > Another thing that puzzles me is - if it is a devkit - why two serial > ports - why not only one ? If the second serial port was "for free" I > could understand - but it seems that the constructor deliberately have > designed it with two ports. > > > Can anyone come up with a theory about the second switch on the front > plate ? it is soldered to the board here: > > http://jpegbay.com/gallery/001326274-7.html#7 > > The first switch is the power switch. > As for the second front switch the soldering location near to U20 > (NE556) could indicate that it has something to do with NMI - maybe a > substitution for a Restore button ? That would indicate that another > type of external keyboard was used - only that it would have to have the > same kind of keyboard matrix... hmm ??? it could also be some kind of debug setup.... a simple sort of "in circuit emulator" .... then pulling nmi would start a "monitor rom" for debugging ... eventually using rs232 for interfacing with some other computer. Message was sent through the cbm-hackers mailing listReceived on 2012-05-07 17:01:05
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