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I'd just like to take a moment to say thanks for all your effort in making AGD work on the Dragon - and for the time and trouble taken to make all these games available - truly a major achievement. I may not play the games myself, but its great to have them available. One game I would love to see on...

Re "Your R0 details are incorrect:"

I've just made the correction to my Compusense DragonPlus document to correct the mistake pointed out by Pernod70. Please use this version...

P Mooney

@tjewell It turns out that was easier then I expected. I did make notes (in a school exercise book) ... and I did find them! Here's what I wrote (exactly as it is in my notes) "ALTERATIONS TO OS-9 TO ENABLE IT TO RUN ON AN UPGRADED DRAGON32 The PIA at FF00 -> FF03 uses a pin to check memory size on ...

@tjewell. What did I do to get OS9 to boot on an upgraded Dragon32? Now you're asking! It was 30+ years ago remember and although I made notes of most of the things we did to our software and hardware the Dragon was just a hobby. I was using other computers for work at the time. I will see what I ca...

@Pernod70... You're quite right, the value in R0 is $71. I must be getting dozy in my old age. Actually, i KNOW I am! And my eye sight's going too. I have the sheet of notes I made of the table and should know better - its correct at other places in the document! I did say the document might need ed...

Your figure for the number of pixels per scanline is correct 904 of which 640 are displayed. The second question about R5, is Yes. The value in R5 is required to bring the total up to the PAL video standard of 312 scanlines per field. 312-286=26 or 25 if it is a zero based count ($1A or $19) but som...

No colour, i'm sorry - and I know that these PROMs were used in some video cabinets to give an RRR GG BBB palette. Maybe there was a plan for that on the DragonPlus . It would have required a second Video RAM bank (like on the IBM MGA board) to hold the corresponding character attributes. The IBM ca...

The dump of my Character EPROM IC22 is Appendix A. I painstakingly laid it out as a table there using a faded printer dump I made of the EPROM contents back in 1986. The hex codes for each byte are exactly what my EPROM programmer output at the time. In the righthand column I have inserted the corre...

COMPUSENSE DRAGON PLUS BOARD.zip This talk about DragonPlus boards has prompted me to get out my second Dragon64 which has the board fitted. That's mine in the picture on the hardware page. And yes it still works fine. When I bought my DragonPlus back in the 1980s it was one of the first and the do...

Before you do anything too drastic, take a small screwdriver and try adjusting the 10k variable resistor. I tweek this from time to time to adjust the color intensity on my Dragons. Obviously you need to have the machine powered up and plugged into your Monitor at the time. Just try a gradual quarte...