archive.worldofdragon.org

It would be very nice to have better pictures of both boards, on both sides.

I can take care of processing them for the wiki.

Thanks a lot!

I'll be bringing a box of untested bits with me. The cartridge port prototype boards came, and I've soldered headers and a DIP switch on, and the Deluxe Composite board from Tynemouth Software also came, but alas both my D32s are broken. I knew one was, and it didn't fix itself in the meantime - it's an issue 2 and C11 (a tantalum by the looks of it) smokes when you turn it on :-O The other I thought worked, but it seems the RAM has gone bad. Unfortunately I wont have time before the Meetup to make any more progress. Next week is my daughter's birthday, then it's dance recital weekend, then I fly out to the UK.

The 40-pin IC to ribbon cable adapter that came with the board originally was blank at the other end. I did add individual headers to each wire today though, so we can connect to the headers on the prototyping boards and hopefully get this going quickly at the Meetup.

(Better photos incoming)

Think I've mapped about as much as I can of this board. Can't see enough of the tracks below those discrete logic IC holders to get much further.

For a remake, would simplify by using 4164s, getting rid of the need for -5V and 12V, and much of the circuitry in the middle left. Also thinking that much of the display circuitry could probably be replaced with something much more modern.

Are you coming to the meetup?

I've spent a couple of evenings on these boards so far. Have been through a few iterations of trying to get it to work - of thinking that not only was the -5V generated on the board, but the +12V was too. But it isn't. Anyway - I now have a bench supply generating the necessary 12V, but still no joy. I can tune into a blank picture, but nothing else yet.

I did find another online review of the board in PCN - courtesy of a handwritten note on the scanned Sprite documents. https://ia800808.us.archive.org/13/item ... pr1984.pdf

There are differences between the prototype board and the green board that was reviewed in PCN - notably around the discrete components below the modulator. I'll keep chipping away at this in the background. One job for very soon is to completely desolder the green board. It's a bit of a mess, could do with cleaning up, and it would be so good to see underneath those awful IC sockets!

dublevay wrote: ↑Tue Jul 23, 2019 10:26 pm I did find another online review of the board in PCN - courtesy of a handwritten note on the scanned Sprite documents. https://ia800808.us.archive.org/13/item ... pr1984.pdf

Nice review, and maybe worth archiving the demo program as it's probably the only official software intended for the board.

Thanks for the heads up!

If you desolder the whole green board, please take the chance of scanning both sides of it or otherwise take nice pictures of it for the wiki page.

Cheers,
Rob

All done. A good night's work with no track lifts! Now I can (when I get a moment), work on mapping out the complete schematic.

OK guys, I have a potentially stupid question.

I've rebuilt the green Sprite board, but it's not running properly yet. It's supposed to be an EXEC &HE002 to get it to run, but this doesn't work for me. I can read the EPROM from the board via the cartridge port, but it seems to start at &HC000. The Sprite ROM is 8K, which I think means it will finish at &HDFFF.

So I either have a decoder issue, a connection issue, or something unexpected (to me) is happening.

My question is does the EXEC &HE002 directly execute the same &HE002 as I can PEEK from BASIC (which is just full of 0x7E), or does some strange decoding happen which makes the EXEC command somehow get routed to the &HC000 location?