Search found 16 matches

by exidyboy
Thu Jul 24, 2025 6:58 pm
Forum: Exidy Sorcerer Hardware
Topic: ESGG External RAM Disk
Replies: 28
Views: 156542

Re: ESGG External RAM Disk

Thanks for that, we have a few ESGG Newsletters English versions, being #5 and #14 to #20 so any of the others would be most welcomed :) Thanks. I have hard copies of the English translation of the first three editions which I will scan presently. Update: Full platen 600DPI TIFF files available her...
by exidyboy
Sat May 10, 2025 10:11 pm
Forum: Exidy Sorcerer Dreamdisk Floppy Disk Controller Discussion
Topic: Dreamdisk Revision 1.1 - Available for release soon !
Replies: 2
Views: 3173

Re: Dreamdisk Revision 1.1 - Available for release soon !

1. Somewhere to connect ground during calibration and testing would be useful. Say a 1.6mm diameter hole between R6 and C4 where you could mount a nice test pin such as linked below or at least a loop of wire. That gives you a free hand to hold either the board or a screwdriver :D I like this style ...
by exidyboy
Sat May 10, 2025 9:31 pm
Forum: Exidy Sorcerer Dreamdisk Floppy Disk Controller Discussion
Topic: Dreamdisk lives!
Replies: 31
Views: 163289

Re: Dreamdisk lives!

As a postscript the Series Resonant Oscillator Circuit on this page by Thomas Scherre is a useful reference to the circuit topology of the 4MHz oscillator on the original Dreamdisk.

http://www.z80.info/uexosc.htm
by exidyboy
Mon May 05, 2025 1:27 pm
Forum: Exidy Sorcerer Dreamdisk Floppy Disk Controller Discussion
Topic: Dreamdisk lives!
Replies: 31
Views: 163289

Re: Dreamdisk lives!

P.S. And yes you can SAVE files:

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by exidyboy
Mon May 05, 2025 1:14 pm
Forum: Exidy Sorcerer Dreamdisk Floppy Disk Controller Discussion
Topic: Dreamdisk lives!
Replies: 31
Views: 163289

Re: Dreamdisk lives!

In the image below the lower trace is a clean 2MHz signal and the top is what I was getting as input to pin 36. Do you mean pin 24 on the WD2793? Pin 36 is WPRT*, not the clock. Just want to confirm. Yes pin 24 sorry. Pin 36 is 4 pins from other corner :oops: Is the graph you are showing the oscill...
by exidyboy
Sat May 03, 2025 5:27 am
Forum: Exidy Sorcerer Dreamdisk Floppy Disk Controller Discussion
Topic: Dreamdisk lives!
Replies: 31
Views: 163289

Re: Dreamdisk lives!

I've done more work comparing the write behaviour of the original and new boards. On both boards I could see the Write Gate go active low and the controller emit a string of negative going Write Data pulses to the drive. Even after checking the Write Precompensation timing again in the test mode I c...
by exidyboy
Sun Apr 27, 2025 10:10 am
Forum: Exidy Sorcerer Dreamdisk Floppy Disk Controller Discussion
Topic: Dreamdisk lives!
Replies: 31
Views: 163289

Re: Dreamdisk lives!

Hi John,

I've swept the 5K pot R6 in minute increments from fully CCW that gives a WPW of 525nS through to fully CW that gives a WPW of 39 nS and I have not found a value that causes writes to succeed.

I will keep looking for other differences in setup or behaviour.
by exidyboy
Wed Apr 23, 2025 8:48 pm
Forum: Exidy Sorcerer Dreamdisk Floppy Disk Controller Discussion
Topic: Dreamdisk lives!
Replies: 31
Views: 163289

Re: Dreamdisk lives!

Here is one Write Data pulse on the original Dreamdisk board from the 80's. You can that the duration of the pulse is 450nS. I find the documentation ambiguous about how you adjust the width of the Write Data pulse. Page 8 of the TI manual for the WD2793 says that: "Write data consists of a ser...
by exidyboy
Sun Apr 20, 2025 9:05 am
Forum: Exidy Sorcerer Dreamdisk Floppy Disk Controller Discussion
Topic: Dreamdisk lives!
Replies: 31
Views: 163289

Re: Dreamdisk lives!

I have connected up an original DreamDisk and "Gender Bender" board that was given to me by Altomare in Paris last year. I can read and write to a Gotek and successfully format a physical floppy with no errors. Pretty impressive considering no adjustments were made to any variable caps or ...
by exidyboy
Sun Apr 20, 2025 4:09 am
Forum: Exidy Sorcerer Dreamdisk Floppy Disk Controller Discussion
Topic: Dreamdisk lives!
Replies: 31
Views: 163289

Re: Dreamdisk lives!

I have installed 7406 and 7407 parts in place of those from the LS family and saw activity on drive select. However I realise that since the drive select lines (in fact all outputs) are open collector and so you need them pulled high by a drive jumpered at that "address" in order to see th...