UKRetrogamer Posted November 4, 2014 Share Posted November 4, 2014 (edited) I tried out my Ti-99/4 PEB earlier (an early on with push-on/push-off power-button) and it worked fine for a while. I could format a 5.25" disk, save from Extended BASIC and reboot, then recover the saved file. Formatting a disk resulted in a number of bad sectors but this could be down to the age of the disks themselves. THEN I decided to use the same 5.25" cleaning disk which I use in my Commodore 1541 and Apple II drives to clean the head in the PEB's floppy. Looks like I made a BIG mistake. Now I can't read OR format disks. Every disk I place in the drive comes up with an error (43 IIRC) when formatting. The drive-cleaner is fine. It still works and cleans the heads on my Apple drives, so I'm wondering what it did to the Ti drive? I'm not sure of the model no. of the drive in the PEB, just that it's single-sided and frickin' HUGE! Assuming a manual clean doesn't work and I've killed the drive for good, what are my options for a replacement drive? I'm pretty sure everything in the PEB is standard (32k, Serial, Drive-controller and hose adaptor). I have a few IBM 5150/5160 PCs with working drives, which appear to be the same size. Would one of these work as a replacement? What readily available options exist for upgrades? Double-Sided. etc. I have an SDtoHXC adaptor but (at least for the time being) I'd like a working floppy-drive in there. maybe a single-height one and maybe even a 3.5" for transfer purposes... Edited November 5, 2014 by UKRetrogamer 1 Quote Link to comment Share on other sites More sharing options...
gregallenwarner Posted November 4, 2014 Share Posted November 4, 2014 (edited) The TI used IBM compatible drives, so I'd say yank those drives out of the PC and stick 'em in the PEB! Just pay attention to the Drive Select lines, and make sure you have your ribbon cable twisted appropriately so that on the TI side it's DSK0, and on the drive side it's drive B. (All PC disk drives are hard-wired to be disk B. Unless it's a REALLY early 5 1/4 drive, in which there's a jumper to configure it as drive A or B.) Double-sided should work with the original TI brand controller card, but to get double density or 80-track working, those would need an upgraded or modded controller card. Edited November 4, 2014 by gregallenwarner Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted November 4, 2014 Share Posted November 4, 2014 You might find the attached PDF file of use.... List of PE Box Compatible Disk Drives.pdf 1 Quote Link to comment Share on other sites More sharing options...
UKRetrogamer Posted November 4, 2014 Author Share Posted November 4, 2014 You might find the attached PDF file of use.... Thanks. Saved for future reference. Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted November 4, 2014 Share Posted November 4, 2014 Also, on that mondo drive you have--a good check would be to make sure there is no grease clogging the rails. Clean them and regrease, that often fixes some problems. Also, you might want to get a long q-tip and some denatured alcohol and try to clean the heads again with that. You may have left some blocking gunk with your head-cleaning disk. Quote Link to comment Share on other sites More sharing options...
Wildstar Posted November 4, 2014 Share Posted November 4, 2014 (edited) Is it a Full-height drive or half-height drive. Mine is the full-height drive which is twice the height of an common 5.25" disk drives commonly found on PCs all the way into the 386 era. The full-height drives looks like big cubes in the drive bay with a slot in the middle for the disk compared to the half-height drives that looks more rectangular when looking from the front face. Edited November 4, 2014 by Wildstar Quote Link to comment Share on other sites More sharing options...
UKRetrogamer Posted November 4, 2014 Author Share Posted November 4, 2014 Oh, it's definitely a full-height drive. Quote Link to comment Share on other sites More sharing options...
+Lee Stewart Posted November 4, 2014 Share Posted November 4, 2014 It is probably a SSSD, which has a felt pad that bears on the side of the disk opposite the head. It keeps the head in contact with the diskette. It is possible that the felt pad has come off. ...lee Quote Link to comment Share on other sites More sharing options...
UKRetrogamer Posted November 4, 2014 Author Share Posted November 4, 2014 That sounds plausible. The cleaning disk is a 3M one with replaceable fabric disks. Rotating fabric against felt may have knocked the pad off. Would it be easy to repair? Just a case of glueing the pad back in place? One thing I *DID* notice was trying to insert a disk was difficult. The opening for the disk is big enough to slide in a deck of cards but pushing the disk home, I felt like I was close to bending it. I found I had to push the disk into the drive while applying pressure to both corners, otherwise I felt it may have folded over on itself. My guess is I'll open the drive up to find the felt pad and a lot of congealed grease. Quote Link to comment Share on other sites More sharing options...
coolio Posted November 5, 2014 Share Posted November 5, 2014 You might find the attached PDF file of use.... Thanks! When this document says "Of no use in TI PEB", what does that mean? I am trying to reconcile that against the claim at the top of the document that ll drives listed are PEB compatible. Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted November 5, 2014 Share Posted November 5, 2014 Actually, any of the drives listed as DSQD (720K) or SSQD (360K) work fine with a TI, so long as you have an 80-track-capable disk controller (Myarc disk controller or HFDC; or any DSDD controller when used with a Geneve). They are compatible, but of no use to a TI user otherwise--and since very few TI users have 720K floppies, the utility reference is mostly correct. Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted November 5, 2014 Share Posted November 5, 2014 The << TEAC FD-235HF >> works GREAT in the TI! Before I got my Lotharek I was using two of them. They are low power drives so you can easily use two in the box at the same time. They also work great with the 80 track mod. You can get them NEW or USED on eBay: << HERE >> (Click on images to radically enlarge) Quote Link to comment Share on other sites More sharing options...
UKRetrogamer Posted November 5, 2014 Author Share Posted November 5, 2014 (edited) I've cleaned the drive manually (TBH, it was cleaner inside than I anticipated). The felt pad is still firmly in place. It's a Ti PHP1250 drive as pictured below and easy to get to the head once the the controller circuit is unscrewed (2 screws with plastic washers) and lifted out of the way. There's a metal shield clipped to the drive arms, but this unclips and lifts off with a little pressure. I'm still getting an error when formatting disks though. While taking the drive apart and removing the circuit-board to get at the head, the connector (labelled P32) came off and I'm not sure which pins and orientation it needs to be placed back with. What's the purpose of this connector. The drive steps through the tracks when formatting even with this disconnected but would formatting a disk while this is unplugged result in the error above? You can see the row of pins in the image below. Which ones do I need to reconnect it to? (Image deliberately blown out, so you can see the pins) Is there a service manual for this drive? Edited November 5, 2014 by UKRetrogamer Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted November 5, 2014 Share Posted November 5, 2014 The drive is an MPI Model B51. Here's a link to the service manual: http://www.osiweb.org/manuals/MPI_B51-B52_Product_Manual.pdf Warning: these drives have been known to launch disks across the room on eject. . .this is not a bad thing, so long as you are expecting it when you open that door. Quote Link to comment Share on other sites More sharing options...
UKRetrogamer Posted November 5, 2014 Author Share Posted November 5, 2014 Thanks. I just downloaded it but I got stopped in my tracks on viewing the cover. I fell off my chair when I read "MINI" Floppy Drive. MINI??? It's one of the largest 5.25" drives I've held! Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted November 5, 2014 Share Posted November 5, 2014 One has to think about when it was produced--it was one of the earliest 5.25 drives. Prior to that, you got to deal with the 8 inch monsters. . .BTW, these are very reliable drives once they are adjusted right. . .they were one of the best full-height 5.25 drives made. Quote Link to comment Share on other sites More sharing options...
UKRetrogamer Posted November 5, 2014 Author Share Posted November 5, 2014 Thanks again for the service manual but I've still no idea how to reconnect P32. I don't suppose anyone has a PHP1250 and could check so I can plug mine back in correctly? Quote Link to comment Share on other sites More sharing options...
UKRetrogamer Posted November 5, 2014 Author Share Posted November 5, 2014 (edited) The TI used IBM compatible drives, so I'd say yank those drives out of the PC and stick 'em in the PEB! Just pay attention to the Drive Select lines, and make sure you have your ribbon cable twisted appropriately so that on the TI side it's DSK0, and on the drive side it's drive B. (All PC disk drives are hard-wired to be disk B. Unless it's a REALLY early 5 1/4 drive, in which there's a jumper to configure it as drive A or B.) Double-sided should work with the original TI brand controller card, but to get double density or 80-track working, those would need an upgraded or modded controller card. Ok... I took a Tandon TM100-2 from an IBM 5160 and tested that in the PEB. Plugging it in without changing anything, It worked as DSK2 so a little Googling found me the location of the "Shunt-Jumpers" and my first experience of such things. (My PC experience started with 720k 5.25" floppies and twisted floppy cables; I came to PCs from an Amiga). So now I have an IBM-branded DS/DD 360K drive in the PEB and it works fine as DSK1. Using Gazoo's Extended BASIC v2.7 cartridge, the Ti Disk Manager will format DS/SD but fails when trying to format DS/DD without even starting the format procedure. However, the Disk Utility (option E) formats DS/DD AND [apparently] verifies as per the attached image. Is this correct or is this tool mis-informing me? I can save a program from Extended BASIC and restore it so to me, it seems like I have a fully working 360K double-sided drive and an upgrade on the PHP1250. I'll wait for those who know this system better to chime in with the truth. With Ti's Disk Manager barfing at DD (it formats SD) but the third-party disk utility passing on a DS/DD format, I'm still not sure if everything is working to full capacity. Edited November 5, 2014 by UKRetrogamer Quote Link to comment Share on other sites More sharing options...
+Lee Stewart Posted November 5, 2014 Share Posted November 5, 2014 Ok... ... Using Gazoo's Extended BASIC v2.7 cartridge, the Ti Disk Manager will format DS/SD but fails when trying to format DS/DD without even starting the format procedure. ... With Ti's Disk Manager barfing at DD (it formats SD) but the third-party disk utility passing on a DS/DD format, I'm still not sure if everything is working to full capacity. The TI Disk Manager does not know anything about double density. ... However, the Disk Utility (option E) formats DS/DD AND [apparently] verifies as per the attached image. ... Is this correct or is this tool mis-informing me? ... The Disk Utililty's count is not reporting the 2 sectors for the VIB (Volume Information Block) and FDIR (File Descriptor Index Record). Other than that, it looks correct. ...lee Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted November 5, 2014 Share Posted November 5, 2014 Use option "M" for "DM2K" that's also on the cartridge. Quote Link to comment Share on other sites More sharing options...
+mizapf Posted November 5, 2014 Share Posted November 5, 2014 The TI Disk Manager does not know anything about double density. I can select "Double density [Y/N]" / "Double sided [Y/N]" in the formatting dialog screen, at least in TI Disk Manager 2. Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted November 5, 2014 Share Posted November 5, 2014 "Mini" is a designation for the 5.25 inch floppy (and related media,) as the 8 inch floppy was the standard size. If you notice, the 3.5 inch "floppy" is actually called a micro-disk. Quote Link to comment Share on other sites More sharing options...
UKRetrogamer Posted November 5, 2014 Author Share Posted November 5, 2014 (edited) From reading around the net, I [think I] understand the original un-modified Ti Disk controller card will work with Single and Double SIDED drives but can only write in Single DENSITY format? This would mean two things to me. 1. My DS/DD IBM drive is effectively only DS/SD as far as the Ti-99 is concerned. (180K instead of the drive's 360K MS-DOS formatted capacity?) 2. The (option E) Disk Utility included in Gazoo's Extended BASIC cart erroneously reports successful formatting of a DS/DD disk on hardware which supports only SD formatting. It would also explain why Ti's Disk Manager 2 utility from the same cartridge coughed up an error when I tried to format a Double Density disk without even attempting to write to the disk. Edited November 5, 2014 by UKRetrogamer Quote Link to comment Share on other sites More sharing options...
+mizapf Posted November 5, 2014 Share Posted November 5, 2014 From reading around the net, I [think I] understand the original un-modified Ti Disk controller card will work with Single and Double SIDED drives but can only write in Single DENSITY format? Right. The original TI controller uses a FD1771 controller that is only capable of single density. Nevertheless, the Disk Manager allows for formatting DD. Quote Link to comment Share on other sites More sharing options...
UKRetrogamer Posted November 5, 2014 Author Share Posted November 5, 2014 (edited) Glad I understood this correctly. Still, it means I've gone from a single-sided drive to a double-sided one which, most importantly works; so today's exercise has resulted in a double win. A working drive and twice the capacity! Edited November 5, 2014 by UKRetrogamer Quote Link to comment Share on other sites More sharing options...
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