View Full Version : Geneve 9640 disk controllers

January 29th, 2015, 10:56 PM
About TI disk controllers, which ones are suitable for the Geneve 9640?

January 30th, 2015, 10:42 PM
Any of the following disk controllers work well with the Geneve 9640:

TI DSSD Controller (the original controller for the PEB), The CorComp DSDD Controller, the Myarc DSDD controller, the Atronic DSDD controller, the SNUG BwG DSDD controller, the Myarc Personality card (a SASI Hard Disk controller), the Myarc HFDC (a DSDD floppy and an MFM hard disk controller), WHT SCSI controller (hard disk), SNUG ASCSI controller (hard disk), or the Nouspikel IDE controller (hard disk). The original TI DSDD controller would also work, though you are not likely to find one. The only ones to avoid are the sidecar type controllers (Percom Data TX99, the little CorComp 9900 Micro Expansion, the Myard MPES50, the Atronic CPS99, or the original SSSD TI Sidecar controller). That pretty much covers it, as I don't think I missed any of the controllers that were available for the TI at one time or another.

February 1st, 2015, 10:52 PM

I've read something about some incompatibilities between MDOS versions and disk controllers. Must MDOS be patched to work with each controller type?, also, some controllers work with SD, others support DD, even one Myarc model works in HD, does all of them have a MDOS compatible boot disk?

February 2nd, 2015, 06:29 PM
There were some issues between earlier versions of MDOS and specific controllers. Really early versions (up to 1.14) had separate versions for floppy controllers (any that would go into the PEB) and Hard Disk controllers (at that time the only two hard disk controllers were the Myarc HFDC (MFM) and the Myarc personality card (SASI). Later versions united the two and added support for SCSI, and later for IDE Hard Disk types. The current version is 6.70. Everything from 5 onward requires that the additional 32K of zero-wait-state RAM modification be done, and it now requires a double sided, single density disk as your boot disk. Earlier versions fit on a single sided, single density disk. As long as the TI formatted disk is 160K or greater, it is big enough--and that is the minimum size for some of the Myarc controllers and the TI DSDD controller when formatting a single-sided disk to DD. All of the other controllers use 180K per side in DD. As long as the controller can read a TI DSSD disk (all of them can), you have access to a boot disk.

February 2nd, 2015, 11:59 PM
Great!, very useful info, thanks again!
So basically any disk controller can work with the Geneve, cool. That leaves me only with the hardest task, find a disk controller :-)

About the 32K mod, I'm not sure my Geneve has it, I can't remember piggybacked ICs except the ones used in the 192KB VRAM upgrade.

February 3rd, 2015, 05:31 PM
You might want to join the Geneve9640 group on Yahoo! and ask about getting that mod done (I think the instructions for it are in the group's files section if you are good with soldering). Tim Tesch is on that group and he is the world's premier repairman for Geneve's. He also does the PFM upgrades to add a persistent, bootable OS (along with some additional usable storage space) onto the Geneve itself.

February 4th, 2015, 11:46 PM
I suppose you mean this group: https://groups.yahoo.com/neo/groups/Geneve9640/conversations/messages

I'll check it for sure!

March 26th, 2015, 12:12 AM
Well, I've finally located a PHP1240; so I'm waiting for it now. I'm eager to try it in the full setup :-)

March 26th, 2015, 06:34 PM
Excellent news! It looks like you will soon be having lots of fun with your Geneve! :)

April 10th, 2015, 10:39 AM
Well, I've been lucky to purchase a fully working PHP1240. After some testing, seems it's 100% functional. Now I need to mod it to get the DSSD :-).

About this one I'm a bit confused; following the explanation here (http://www.mainbyte.com/ti99/upgrade/upgrade.html), do I need to mod the EPROMs (pulling pins, adding resistors, etc.) or simply burn and replace as suggested in the zip file with the binaries?

April 11th, 2015, 11:10 AM
To use it is DSSD mode, no changes to the controller are necessary at all. Just get a standard 360K drive and it will format to 180K (DSSD). It is possible to modify it to 80-track per side operation (that requires a new DSR and a couple of other changes) and get 360K on a nominally 720K drive.

April 12th, 2015, 02:48 AM
Yep, indeed, the mod is about getting 80 tracks, my bad :oops:. I've a serious mess with that...
Looking at the changes, they're just related (except switch that enables swapping the pair of 80 tracks disks) to enabling the use of 2764 EPROMs instead the pulgin compatible 2532 ones. So, as I can replace the original mask roms with 2532, I suppose that only need to do that to get a fixed pair of 80 tracks drives.

Is the Geneve totally compatible with these 80 tracks drives?

EDIT: In fact I was so messy about acronyms that I was creating a totally wrong disk type. The Geneve was simply unable to read it :-P. Now, with the correct DSSD one it works fine!. Thanks!

April 12th, 2015, 05:40 AM
The Geneve actually ignores the DSR on the card when it is operating in default mode (there are ways to force it to look at a card's DSR, but I've never needed to use (or remember) them). I have used it to format 720K disks using CorComp, BwG, Myarc, and Atronic disk controllers--I never tried to use the TI controller and an 80-track disk to see if I could format a 360K single-density disk that way. The Geneve Master DSR does have 80-track support built in, so it might work.

April 12th, 2015, 10:55 AM
Actually, I can't make the 80 tracks formatting work from MDOS 2.21. Using "FORMAT A: /2 /9 /80" ends up giving weird messages or simply failing. Instead, formatting a floppy to DSSD 80 tracks with my PC, MDOS sees it as a 360KB disk.

MDOS 2.00 manual does indeed mention the 80 tracks support; but as a quad density (?). Maybe I need a later MDOS version or a formatting tool other than the FORMAT command.