Dragon 64 repair

[dublevay]

Can you post some good pics of the to of the board please?

[dublevay]

Sorry. Just found your top of board pic. Strangely, you only have 4164 chips in there. So it is odd that the additional boards are included, as that motherboard does not look modded.

Please keep those other boards safe. They are important to the history of these machines and Bob Hall, who was rather the mad professor on the Dragon.

Anything else unusual about the machine? When i saw it on Ebay, it had an extra switch at the back, probably for a Dragonplus board originally.

[Kepler]

I posted this earlier. If you need any more, please let me know.

IMG_20260305_145142-edit-20260305145155.jpg (6.78 MiB) Viewed 820 times

[dublevay]

I will have to check out the NDUG articles. The nodding of the 32 and 64 was rather different. I recognised this board by the sticker on the SAM BTW. One of my 32s from that seller also has it.

[dublevay]

Also just noticed your comment about additional RAM chips being soldered on. That would have been making it either 128 or 256K. So the board was definitely paired with the mod board.

FWIW, I've not got either of the 32K machines working yet either. The old wire wrap is just another layer on the aged nature of these machines.

[Kepler]

This is how it looked originally:

IMG_20260221_142606.jpg (6.68 MiB) Viewed 819 times

IMG_20260222_155514.jpg (6.41 MiB) Viewed 819 times

IMG_20260222_155616.jpg (1.43 MiB) Viewed 819 times

[Kepler]

Mr Hall sounds like a fascinating person. What information is known about him?

[dublevay]

Personally, not a lot, but I believe we both bought from his son, so he might have some background.

Very good that you took the pictures. Were the additional 8 RAM chips all 4164? Think your upgrade would be 128K.

[Kepler]

They were 4564. Yes, it was a 128k upgrade with MMU.

[dublevay]

Some images of one of mine - which has Mk I MMU written on the bottom, but which actually checks out to be Bob's Mk 2 board.