AwkwardPotato Posted December 13, 2017 Share Posted December 13, 2017 I finally went and bought myself a PEB, listed as untested, and complete with RS-232, Disk Controller, and 32K cards. And as seems to be usual with untested systems, it doesn't work. (at least not entirely) I typed in the following program listed in the Disk Memory System manual, in order to test the drive: 100 OPEN #1:"DSK1.X" 110 CLOSE #1 The LED on the controller lit up for a fraction of a second, but the drive itself was lifeless, with me getting an I/O ERROR 00. The manual, however, says that I should normally get an I/O ERROR 06, and that 00 means that the drive could not be found. For what it's worth, the drive spins up when the PEB is first powered on, and the LED on the drive lights up when shutting it off. Where should I start with troubleshooting this? (BTW, I thought that members here were exaggerating about how loud the PEB's fan is; turns out it really is that loud ) Quote Link to comment Share on other sites More sharing options...
+9640News Posted December 13, 2017 Share Posted December 13, 2017 Do you have the original full height floppy drive, or does it have perhaps dual 1/2 height floppy drives? I ask because if it is the original drive, then likely nothing has ever changed on the cabling and it would be just a matter of making sure the cable was good and plugged in to both the drive and card. Pictures may be helpful just so we can visually see in the PEBox as well as see the drive. If it is 1/2 height drives, then it could be an issue of a dip setting not right on the drive or something like using a PC twisted drive cable which is not what you want to use for the TI system. 1 Quote Link to comment Share on other sites More sharing options...
+9640News Posted December 13, 2017 Share Posted December 13, 2017 Oh, not sure, but did you have a diskette in the drive and was the drive door closed? 1 Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 13, 2017 Author Share Posted December 13, 2017 It's the original single full-height drive, and I've tried with both diskette and no diskette, but to no avail. Quote Link to comment Share on other sites More sharing options...
+mizapf Posted December 13, 2017 Share Posted December 13, 2017 The bad thing is that different disk controller may deliver different error codes. For instance, when no disk is inserted, the OPEN command yields a I/O ERROR 06 with the standard TI FDC, while it returns an I/O ERROR 02 with the HFDC. What controller are you using? Quote Link to comment Share on other sites More sharing options...
+adamantyr Posted December 14, 2017 Share Posted December 14, 2017 Have you tested with multiple diskettes? And are you sure they are DSDD 360k disks and not HD 1.2mb ones? The latter can't be read or written to by the older devices. Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 14, 2017 Author Share Posted December 14, 2017 (edited) I'm using the original TI PHP1240 card. I actually don't own any TI formatted disks, and I'm unable to format any as I'm still waiting on my copy of Disk Manager, so I'm using blank DSDD disks. I assumed that the disks themselves wouldn't be an issue as the manual says that the two lines should work even without one. Edited December 14, 2017 by AwkwardPotato Quote Link to comment Share on other sites More sharing options...
+arcadeshopper Posted December 14, 2017 Share Posted December 14, 2017 (edited) did you do DSK1 or dsk1 all caps for devices the error 00 is open-disk drive specified can not be found.. manual is here: ftp://ftp.whtech.com/datasheets%20and%20manuals/Hardware/Texas%20Instruments/PHP1800%20Disk%20Drive%20Controller/Disk_Memory_System.pdf Greg Edited December 14, 2017 by arcadeshopper Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 14, 2017 Author Share Posted December 14, 2017 I used all caps. Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted December 14, 2017 Share Posted December 14, 2017 Considering the age of the everything including the drive, cable, unknown storage method and possibly getting knocked around in transit... Oxidation may have built up over time on the drives contacts, preventing proper data transmission. Cleaning the contacts on the drive, and the connector could be a possible first starting point. Have you opened up the P-Box to inspect the drive? It's possible that the connector is only partially connected/seated I've actually experienced this one once. Back in the 80's a guy was having issues with a used box he purchased. It turned out the seller in his haste to re-install the original drive, didn't fully seat the connector. Of course there could be other issues which make the controller think the drive is missing, like the controller itself being defective, but I'd fully inspect the cabling and related issues first. I've found most problems turn out to be grounding and connection issues. Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted December 14, 2017 Share Posted December 14, 2017 Oh, one last thing, are you sure. The drive is set as DSK1 and not 2 or 3? With old equipment you never know how it"s been used or modified and returned to it's original state. Quote Link to comment Share on other sites More sharing options...
+9640News Posted December 14, 2017 Share Posted December 14, 2017 Are you getting a floppy disk version of a disk manager, or are you getting the module "Disk Manager". If the module, then I would just wait and not worry at this point other than checking contacts and making sure the cables are connected properly. If you are getting a floppy disk version of a disk manager, realize you will need either the modules Extended Basic or Editor/Assembler. If Extended Basic, hope whoever is sending you the disk has a loader for Extended Basic on the diskette with an autoload that will load the diskette version of whatever disk manager you are getting. Beery Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 14, 2017 Author Share Posted December 14, 2017 - Omega: I'll check the cabling and clean the connectors in a while. The drive has the termination resistor pack on it, so I assumed it was DSK1. However, I also tried using DSK2 and DSK3 just in case, and neither worked. - BeeryMiller: I'll be getting the module version. 2 Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 15, 2017 Author Share Posted December 15, 2017 Well, I've cleaned all the connectors between the console and the disk drive -- mainboard, speech synthesizer, flex cable foot, flex cable interface, PEB backplane, disk controller, and disk drive. Unfortunately, it still returns the same error. Between the flex cable assembly (foot, interface card, and the cable itself), the disk controller, and the drive, which is most likely to be the issue? Quote Link to comment Share on other sites More sharing options...
+adamantyr Posted December 15, 2017 Share Posted December 15, 2017 Did you say 32k cards? You have more than one in the system? It sounds like a drive issue, if the disk controller lights up but the drive doesn't. Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 15, 2017 Author Share Posted December 15, 2017 (edited) Nope, only have one 32k card. Edited December 15, 2017 by AwkwardPotato Quote Link to comment Share on other sites More sharing options...
+helocast Posted December 15, 2017 Share Posted December 15, 2017 (edited) It's the original single full-height drive, and I've tried with both diskette and no diskette, but to no avail. Having resurrected two PEB with original PHP1250 drives, I found on both that the previous owners had taken out, never had the correct termination pack installed in the drive, or like Omega alluded to had the drive non-terminated (configured in a multi-configuration). They had wire jumpers and or 1/2w resistors fitted (and not reliably) where it should have been a https://www.ebay.com/itm/QTY-100-MDP1403-151G-14-PIN-DIP-150-Ohm-2-ISOLATED-RESISTOR-NETWORKS/121446236186 or comparable. Nothing unique about them, just a SIP resistor network in a DIP package. Edited December 15, 2017 by helocast 2 Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 15, 2017 Author Share Posted December 15, 2017 Here's the configuration of the termination pack and the shunt pack: From what I've read on The TI Tech Pages, the shunt pack is configured for the head to be loaded by the select line, and for the drive to be selected by SEL1. The termination pack seems to be the original part. Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 15, 2017 Author Share Posted December 15, 2017 I've tested the drive by shorting some of the pins to ground -- namely the Motor Enable, Drive Select, and Step pins, all of which work. I'm assuming this means that there is an issue with the controller card instead. Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 16, 2017 Author Share Posted December 16, 2017 (edited) Well, I did some probing on the controller card, and I found this: - Disk Select 1 comes from an 8-Bit Addressable Latch (74LS259, U23) - The Clear, Enable, Data, and Address lines to the 74LS259 seem to work, but Disk Select 1 (Pin 9) never goes up Does this mean it's likely U23 that's bad, or is there probably something else going on? Edited December 16, 2017 by AwkwardPotato Quote Link to comment Share on other sites More sharing options...
Stuart Posted December 16, 2017 Share Posted December 16, 2017 Well, I did some probing on the controller card, and I found this: - Disk Select 1 comes from an 8-Bit Addressable Latch (74LS259, U23) - The Clear, Enable, Data, and Address lines to the 74LS259 seem to work, but Disk Select 1 (Pin 9) never goes up Does this mean it's likely U23 that's bad, or is there probably something else going on? Do the Disk Select 2 and 3 lines (pins 10 and 11) go active if you try to select those drives? Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 30, 2017 Author Share Posted December 30, 2017 (edited) Pins 10 and 11 did go active when selected. I finally got a bit of time to work on the TI, and started messing with the card. I replaced the 74LS259 with a socket, and hardwired Pin 9 to +5V. I also lifted Pin 32 of the FD1771, and hardwired Pin 32 of the socket to +5V. This caused the Drive Select 1 to always be active. When powering up the PEB, the light comes on, and when powering up the console the head in the drive knocks several times. However, when attempting to access the drive in either Disk Manager or TI Basic, it still returns error 00. Edited December 30, 2017 by AwkwardPotato Quote Link to comment Share on other sites More sharing options...
pcoderdude14 Posted December 30, 2017 Share Posted December 30, 2017 Hey there... I have the same problem with my CorComp FDC , in that I get an "I/O error 00" too. The LED on the card "blinks" when I try to access the drive, but, the disk drive pretty much does nothing, when tried for access!?! Any ideas would help... Sincerely,... Jt Quote Link to comment Share on other sites More sharing options...
Stuart Posted December 31, 2017 Share Posted December 31, 2017 Pins 10 and 11 did go active when selected. I finally got a bit of time to work on the TI, and started messing with the card. I replaced the 74LS259 with a socket, and hardwired Pin 9 to +5V. I also lifted Pin 32 of the FD1771, and hardwired Pin 32 of the socket to +5V. This caused the Drive Select 1 to always be active. When powering up the PEB, the light comes on, and when powering up the console the head in the drive knocks several times. However, when attempting to access the drive in either Disk Manager or TI Basic, it still returns error 00. With the new 74LS259, does Disk Select 1 (pin 9) work properly when you try to access the drive (with no hardwiring)? If yes, does that signal also make it through to the floppy connector? Quote Link to comment Share on other sites More sharing options...
AwkwardPotato Posted December 31, 2017 Author Share Posted December 31, 2017 The replacement 74LS259 hasn't arrived yet, however I will post an update when it does. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.