I found these files on the Spanish Dragon sites, had some PCB’s made in a nice fiery Red and bought the parts off feeBay built it and set the variable resistors and the trimmer pot. Now have a Gotek compatible disk drive...
Hi Richie that's great news glad you got all working o.k . Just waiting on some PCB's to turn up should be Tuesday, but sod's law I'll be a way for a few days. Not tried the Goteks with the USB-USB cable as yet. You'll have to keep us all updated with what software you manage to get working ie. any of the Co-Co stuff?
Yeah a LOT more straightforward than the Oric getting a disk drive setup on a Dragon. The fiddly bit was setting RV9,RV10 and C7. I found some posts on the Spanish forums with values for the 10K variable resistors and just tweaked C7 until it would read/write and format. I was surprised that it supports 720KB DSDD drives ( I did use DPlus 4.9B which was a complete rewrite of DragonDos ) so I have a couple of blank disk images with 720KB free which will take some filling up using a 32KB machine
Well I'm glad it's all working o.k., I did spot the pink label on the EPROM and wondered what the marking reffered too, so now I know. Great that it supports 720K disc's as well. Is the next step to upgrade memory? I've been playing with my CPC, think I made a mistake with one thing, I decided to de-solder the Floppy drive cable from the motherboard, with the idea of fitting a header block, and actually a box header would physically fit, allowing different cables to be made up internally. All removed ok. However it turns out the drilled holes in the PCB are too small to allow the diameter of the pin headers to fit through. I've for now, filed down 26 individual pins and re inserted them back in the boxheader and soldered in, however the solder on some of the pins doesn’t seem to have flowed very well, on the surface where I'd fileed them down, so may have to remove, and go back to what was there before. I've also de-soldered both the O.S & FDD ROMS. Standard OS at the moment but have got PARADOS instead of AMSDOS. I've also going to receive the shipment of PCB's they were due to be delivered end of day Tues 13th.. Seems they are out for delivery today. However my deal on buying a number of XC9536's from China, well payment has gone through but hasn't yet shipped them, bit annoyed about that, I guess their trying to find chips that look similar to remark them. I hope not but have to wait and see. Otherwise I'll be modifying each board to add a 3.3V regulator and using XC9536XL's which seem to be much easier to get. And are 5V tolerant. I hope we see some more additions to the Dragon moving forward. P.S where are we with the Oric bits and pieces?
I meant to add I'd seen some expansion boards that allow additional cards to be plugged into the expansion port vertically, similar to the MX4 style Motherboard expansions on the CPC.
Wonderful to see how this once humble, quiet little tape-only beast has now become a fully-fledged roaring retro disk-drive capable micro, Rich - excellent work, fella! It's so rewarding for you and satisfying for us all to see vintage, classic machines brought fully up to spec - and then some - due to the great affection retronauts like you show for the old warhorses. Great stuff, Rich and keep up the good work/informative threads, mate. Hope you and Sonia are keeping well and keeping morale up - Bev missing her folks up in Sunderland currently living under tight social distancing restrictions (her dad's 80th b'day celebrations a few weeks ago had to be cancelled entirely which naturally upset a lot of the family - my dad's coming up in December so we'll see how we get on here...).
I made some Mother X4 connectors, they allow one vertical MX4 PCB to be connected to the CPC with a pass through edge connector. It is built for U.K. CPC machines with edge connectors and not the centronics of a Schneider machine. I have 6 built do you want one anyway, I was going to give Andy one for his 464.
Re the Oric, The dealer I phoned him yesterday and he has retrieved a TC01 with faulty graphics chip and will remove the drive from that, so it is a secondhand one but it will be tested. He reckons Wednesday for sorting out payment and shipping. It turned out he had no brand new ones left. I also had a new Gotek mount made and delivered, this one is based on the Einstein dimensions and is taller than the +3/6128 Gotek mount and will fill the space behind the fascia properly with no gaps. It is a backup plan, once I have the new 3” drive and fitted we can have the Gotek as drive B.
As ever, brilliant news and work your end, Rich. I'm very very grateful.... and about to give you a quick buzz now! Many thanks.
I think Andy; your going to be very pleased with the work Richie is putting in, even down to locating a drive in the first place. Well done Richie.
Absolutely, Graham. We've just had a natter and good old catch-up and as ever - the fella's done MAGIC! All being well, we should hear this week how much the chap wants for the working ex-Einstein 3" drive but it doesn't sound like it will cost the earth but will instead really bring the originality back to the microdisc AND add a bonus B: drive Gotek - everyone's a winner, Graham - cheers, mate.
Totally. It's currently cupboarded the old CPC - buried under Speccy and Atari game boxes, Graham. Since Rich kindly loaned it to me, it's had about 20mins out in action here, test loading a couple of tapes which is a shameful situation but until the upheaval is complete this end, I've still got stuff to put AWAY, let alone get out to PLAY! The wait, for now, goes on, but the Ammy will get a sesh before Xmas - promise! LOL. ;-)
I know this is a bit of an old thread but what type of dragon files did you put on the usb for the gotek? I've built the card but cant get any 5 1/4" drives to format or read and I already have a gotek i can use. Did you need to mess with c7 with the gotek? thanks.
It's been a long time since I built one of these but I had to tweak the two variable resistors and the variable capacitor to get the gotek or a 3.5" drive to read/write and format reliably. There are some figures out there which give readings from various points on the PCB with an Oscilloscope but I did mine by trial and error. Adjusting all three should get any drive to R/W and Format - look at the picture of mine for reference ( unless you have a SMD version ) The emulated Dragon disk files are .VDK files so depending on what firmware the Gotek has for instance HxC firmware will need VDK images converted to HFE files whereas Flashfloppy can use VDK files natively.
Thanks for the reply, I did try my gotek late last night which has flash floppy on and that worked perfectly without any tweaking. I built two boards so I might try tweaking one to see if I can get a floppy drive working just for the hell of it!
That is an amazing project. Would you please elaborate some more, i.e. some screenshots of the operations to be done on the Dragon, as DOS commands...etc... What about the buiding of the interface board? Is it hard? I might be interested in bulding/buyring one for my Dragon 32 - btw do you need the 64 version? Thanks.
https://hardware.speccy.org/temp/Dragon-1.html https://colorcomputerarchive.com/re...n Microcomputer (J. Johnson and K. Davis).pdf These are the sites I used, I made one with a WD controller chip and another with a TMS one. You really need a oscilloscope to set the timing and that's about it, I didn't have much luck with an actual floppy working but gotek worked first time. Other than the controller chips the rest are just logic ic's and a eeprom for the firmware.
The site I first found was the first one @tecfixed mentioned. I just sourced the parts off the list and built one based around the WD2797 FDC. Then I was able to find a 3d print case design and got one made up for me. The hardest part was getting the calibration right. At the time I didn't have a decent oscilloscope so I had to use the multimeter and resistance values. It took a couple of tweaks but I eventually got it working with a 3.5" Floppy and a Gotek. I cannot remember where I got the Gerbers for the PCB I had made with the Dragon Data logo on it but I still have one in Red in my stores. I don't have a Dragon anymore so I wouldn't be able to calibrate one anymore. I moved over to a 64K Tandy CoCo2 with a CoCoSDC for my 6809 fix. It makes life a lot simpler. You can use them with Dragons as well so you can access VDK disk images. It's been a while since I made one of these so I don't have any photos or video of it anymore sadly.
