• Please review our updated Terms and Rules here
  • From now on we will require that a prefix is set for any items in the sales area. We have created regions and locations for this. We also require that you select a delivery option before posting your listing. This will hopefully help us streamline the things that get listed for sales here and help local people better advertise their items, especially for local only sales. New sales rules are also coming, so stay tuned.

WTB: High density XT floppy controller

D

David_M

Veteran Member
Joined
Oct 1, 2016
Messages
647
Location
Melbourne, Australia
I'm looking to a high density floppy controller for an XT.
Preferably in Australia but willing to look further afield if the price is right.
 
David, I came across one of these by shear luck one day. They are pretty rare. The thing is we have 8 bit isa XT IDE now but why has noone made an HD XT floppy card modern?
 
They have albeit a while back, [Here] and [Here], I generally use a 16-bit IDE/Floppy controller and stick the HD floppy Bios somewhere.
 
I've been meaning to run one of Sergey's FDC boards and see if it support single-density operation, as the National Semiconductor controller chip supports it. I'd probably end up reworking with both a 34-pin header and a 34-pin card edge connector, so it could be used either/or (e.g. in place of the original IBM PC and XT controller without a cable change). Few other tweaks as well. If this is something folks are interested in, I can run boards and do a kit as I've done with the XT-IDE rev 3 and 4.
 
glitch said:
I've been meaning to run one of Sergey's FDC boards and see if it support single-density operation, as the National Semiconductor controller chip supports it. I'd probably end up reworking with both a 34-pin header and a 34-pin card edge connector, so it could be used either/or (e.g. in place of the original IBM PC and XT controller without a cable change). Few other tweaks as well. If this is something folks are interested in, I can run boards and do a kit as I've done with the XT-IDE rev 3 and 4.
Click to expand...

I would buy one from you for sure..
 
Al Hartman said:
If you use the right chip, it works fine with Single Density. I wrote bootable Model I TRS-80 DD floppies with mine.
Click to expand...

There's some external RC filter circuitry that can be different depending on if the design was intended to support single-density or not. I haven't looked at Sergey's design to see how it handles this.
 
I remember giving away a bunch of WDC floppy controller chips to someone on this forum some years ago (I fished them out of company e-waste bin) there must've been forty or fifty chips.
 
dorkbert said:
I remember giving away a bunch of WDC floppy controller chips to someone on this forum some years ago (I fished them out of company e-waste bin) there must've been forty or fifty chips.
Click to expand...

I've offered a tube of WD37C65B PLCC chips here with no takers.

If you use the NS 8477 FDCs, no external filtering is needed for FM. 8473s have the benefit of supporting MFM 128-byte sectors in addition to regular FM and MFM. Provide a clock or crystal and bus interface and you're good for 4 drive support--no OC drivers needed.
 
ChrisUnionNJ said:
Quote Originally Posted by glitch View Post
I've been meaning to run one of Sergey's FDC boards and see if it support single-density operation, as the National Semiconductor controller chip supports it. I'd probably end up reworking with both a 34-pin header and a 34-pin card edge connector, so it could be used either/or (e.g. in place of the original IBM PC and XT controller without a cable change). Few other tweaks as well. If this is something folks are interested in, I can run boards and do a kit as I've done with the XT-IDE rev 3 and 4.
I would buy one from you for sure..
Click to expand...

Count me in for a pair of kits just in case you run the batch...
 
Cool, the 82077 used in this project can work with ED floppies. I wonder if the BIOS could support this, no idea about its features...
 
You must log in or register to reply here.
Back
Top