Uncreative Labs

Joined: 21 May 2006 Posts: 47 Location: London, England

I am looking for a couple of MFM/RLL controller cards, one for an RLL drive, the other for MFM. Something along the lines of a Western Digital WD1002 or WD1004 would be perfect! Anyone have anything suitable?

Thanks in advance Smile

Joined: 03 Jun 2008 Posts: 2 Location: Wiltshire UK

Got a couple of full-length 16-bit Tatung controllers.
Give me a day and I will dig them out and see what they are.

Geoff

Joined: 03 Feb 2006 Posts: 488 Location: pennsylvanai

ok yiou need a western digital 9 bit card.
the wd1002-wx2 ( 2/3 length) watch out if the bios chip is smaller then the socket, this is a clue that the bios is proprietary and possibly will not give you anyn options 9mfm only) the other ones you mentioned "square cards" do not have this problem.
the wd1002-wx1 ( square) and the -gen cards and one other model, also a square card are all fairly close and should be fairly cross compatible.

there are some docs on this site click on the memory chips to get them. they will help.
remember the at and xt ll formats are different,
mark the drive to remind you what card to use it with,

you will get errors if you try to RLL a mfm drive.
the mitsubishi MR535 will go either way 40m/60m
read the old literasture, they claim some mfm drives will take a rll formatting.
I have some special "super rll" cards- PERSTOR, that suposedly will rll a mfm drive, think it makes a st-225 9 20m) into a 39m drive. 16 bit only.

I have two st 4096 drives 80 megs, but you woud need a large ship to carry them across the pond.

Joined: 03 Jun 2008 Posts: 2 Location: Wiltshire UK

Well, I found the cards.
Two Tatung PWB-2012 Rel 02 Disk Adapter (thats what it says on them) cards. Full length, 16-bit.
I have not been able to find them with any search engine Have tried Copernic which defaults to searching a set of twelve other engines. Someone may know what they are.
It is certain that they are hard and floppy controllers - there are two sets of pins for the data cables, two sets of pins fordrive control. One is marked FDC (I assume floppy) and the other is marked WDC (Western Digital perhaps). Ther is also a DIP-Switch set and a jumper block.
Probably the only way to find out would be to install a card, and see if it handled 26 Tracks/sector, or only 17.
Let me know if you are interested.
Geoff

Joined: 03 Feb 2006 Posts: 488 Location: pennsylvanai

the 16 bit rll controller had oen setting or drive that would allow a st-238 615-4-615 same as a st-225 to work with 26 sectors instead of 17.
at they time all the 286 bios drive tables ONLY could see 17 sectors, this allowed a rll st-238 dru=ive to work in a very old IBM AT or clost compatible with a limited drive table.

when I was at intel in 1989, they talked about IBM AT;s made in the UK with an improved drive table that included the seagate st-251 drive 820-6-821 11 7 ( 17 sectors)
the IBM ps/2 came aout about that time and development or improvement of the original IBM AT stopped.
clone bios' would work.