archive.worldofdragon.org

For what it's worth this is the code that the diag card uses to identify the 6309. ; ; Test to see if CPU is a 6809 or 6309. ; ; GetCPUType ; lbsr LCDClrScr ; clear LCD screen leax LCPUIs,pcr ; point to message lbsr DevWriteStr ; write it ldb #$ff ; setup b FCB $10 ; This will be CLRD on 6309, CLRA ...

CoCo 1 has 5V,12V *AND* -12V. Dragon has 12V and 5V CoCo 2,3 have only 5V. What is important though is the line that carries -12V on the CoCo1, carries +12V on the Dragon. Though unless you are using them they can be left unconnected. Certainly for a ROM cart you shouldn't need them. Cheers, Phill.

A Dragon 32 board I thought was dead magically came back to life for as long as I held a probe to the RESET line on the CPU - turned out that pin was just not making a good connection in the socket! I had a problem almost identical to that on one of my Jupiter Ace boards except it was IIRC A8 of th...

Reg3 looks like it has the insulation kit there, I think it consisted of a piece of mica? and an insert washer for the screw hole, along with some thermal paste (the white stuff round it).

Something like this : https://uk.rs-online.com/web/p/heatsink ... s/7128225/

Cheers.

Phill.

robcfg wrote: ↑Sat May 23, 2020 12:30 pm That's nice, thank you!

I'd add a Gotek floppy drive emulator to the list.

That's effectively what DragonDrive is isn't it? A DragonDOS cart with built in Gotek running flash floppy.

Cheers.

Phill.

Yeah Dragon/Tandy and BBC analog joysticks do theings the correct way a potential divider, which is wy you never have to calibrate them because they are in effect self calibrating. However to read them you need to be able to read the voltage level which means some sort of DtoA and a comparitor. The ...

Posted this on the FB group but adding it here also as it may be useful.... Hi all, Some power draw measurements done on a Dragon 32 Board. Board 1, 16x4116 memory +12V draws 165mA +5V draws approx 660mA -5V draws approx 40mA Board 2, 8x4164 memory +12V draws 0mA unless a cartridge uses it.** +5 dra...

John W has also done a modern re-creation of the lower case board if you are on facebook, he posts regually there,

Cheers,

Phill.

Regarding OS9 crashing, I'm not sure if this is relevant but stock OS9 doesn't boot on upgraded D32s because it expects the D64 serial port to be present at $ff04. On a D32, OS9 ends up writing to the low pia instead and freezes the machine during boot. I think the D32 64K upgrade guide describes h...

I've used the Godil based emulator, and it is indeed excellent, being able to supend the CPU and look at registers / memory / single step is
indeeed useful.

There is anew version that has a proper level translator board and a cheapish FPGA development board.

Cheers.

Phill.