Search found 251 matches

by prime
Sat May 23, 2020 10:44 pm
Forum: Dragon Hardware
Topic: Adapting PC Joystick
Replies: 1
Views: 1679

Re: Adapting PC Joystick

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 ...
by prime
Fri May 22, 2020 12:51 pm
Forum: Dragon Hardware
Topic: Dragon 32 Power draw.....
Replies: 0
Views: 1912

Dragon 32 Power draw.....

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...
by prime
Wed May 13, 2020 2:37 pm
Forum: Dragon Hardware
Topic: Dragon 200 circuits and lower case mod circuits
Replies: 7
Views: 3513

Re: Dragon 200 circuits and lower case mod circuits

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.
by prime
Wed Apr 29, 2020 10:04 pm
Forum: Dragon General
Topic: Dragon power board problems!
Replies: 9
Views: 4980

Re: Dragon power board problems!

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...
by prime
Wed Apr 22, 2020 1:26 pm
Forum: Dragon General
Topic: Debugging a real Dragon with NoICE - serial port
Replies: 7
Views: 4664

Re: Debugging a real Dragon with NoICE - serial port

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.
by prime
Thu Mar 26, 2020 8:12 pm
Forum: Dragon General
Topic: Dragon Beta OS-9 disks
Replies: 17
Views: 8777

Re: Dragon Beta OS-9 disks

Thanks, at least I can now rule out any mis-interpretation of the floppy format. Are all discs bootable? Took another look at the driver last night, the implementation of the memory banking looks overly complicated, and is probably now broken. The memory sub-system in MAME has improved immensely si...
by prime
Thu Mar 26, 2020 1:32 am
Forum: Dragon General
Topic: Dragon Beta OS-9 disks
Replies: 17
Views: 8777

Re: Dragon Beta OS-9 disks

Who actually has these Beta OS-9 floppies? Could they be re-imaged in a more suitable format such as HFE? I have a copy of them, I can rig up a grease wezel setup and archive them at some point if you want. Yes please :) I've uploaded the zipped .scp files of the disks to : http://penguin.stats.war...
by prime
Wed Mar 25, 2020 7:03 pm
Forum: Dragon General
Topic: Dragon Beta OS-9 disks
Replies: 17
Views: 8777

Re: Dragon Beta OS-9 disks

Pernod70 wrote: Sat Mar 21, 2020 1:33 pm Who actually has these Beta OS-9 floppies? Could they be re-imaged in a more suitable format such as HFE?
I have a copy of them, I can rig up a grease wezel setup and archive them at some point if you want.

Cheers.

Phill.
by prime
Tue Mar 03, 2020 11:04 am
Forum: Dragon General
Topic: Dragon ROM souce code.
Replies: 3
Views: 2743

Dragon ROM souce code.

Hi all,

Just to let you all know I have put the dissassembled, re-assembleable and commented source for the Dragon 32 & 64 ROMS online at :

https://github.com/prime6809/DragonRom

Cheers.

Phill.
by prime
Sat Jul 27, 2019 12:14 pm
Forum: Discuss This Site
Topic: Hardware Forum Needed?
Replies: 3
Views: 5480

Re: Hardware Forum Needed?

Sounds like a good idea to me.

Cheers.

Phill.