+Vorticon Posted July 4, 2015 Share Posted July 4, 2015 Hi. As some of you know, I frequently experiment with interfacing the TI to the outside world using the PIO port. Lately however, the computer stopped recognizing the label "PIO" for printing purposes, even though I am still able to access the port at the low level normally through assembly language and my interfacing activities are not affected. For example, trying LIST "PIO" from TI BASIC will give me an I/O ERROR 00. My current RS232 card is TI stock with the HDX modification and the serial ports work just fine as well. I swapped that card with an unmodified stock RS232 one and the PIO port was again recognized as usual, so the problem must lie with my original card. What kind of failure could trigger such an odd behavior? Quote Link to comment Share on other sites More sharing options...
Opry99er Posted July 4, 2015 Share Posted July 4, 2015 Indeed bizarre... Not being a hardware guru, (and this may be a dumb question) is there an IC on the rs232 that handles high level interpretation? Or are all BASIC I/O functions interpreted prior to accessing the card? I know BASIC is just simply interpreted by GPL, then by machine code... But--- Seems if low level access works properly, there is a disconnect there somewhere. Quote Link to comment Share on other sites More sharing options...
+InsaneMultitasker Posted July 4, 2015 Share Posted July 4, 2015 Low level serial and parallel access can be accomplished without the EPROM or DSR code. On the other hand, named devices such as "PIO" and "RS232" and routines such as the Circular Interrupt Buffer (CIB) do require a DSR. Fred's HDX DSR is loaded into RAM (and IIRC is split into two 4k banks). My bet is that the DSR has been partially or completely overwritten or corrupted. If you have not tried reloading the DSR into the RS232 I would try that first. Unfortunately, DSR corruption is a downside of the HDX, IDE, RAMdisks, and similar devices without a fully write-protected DSR (i.e., EPROM). 1 Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted July 4, 2015 Share Posted July 4, 2015 Unfortunately, DSR corruption is a downside of the HDX Yup! Everything goes along PERFECT... until the battery starts getting weak. At he first sign of trouble I recommend replacing the battery. Quote Link to comment Share on other sites More sharing options...
+Vorticon Posted July 6, 2015 Author Share Posted July 6, 2015 Yes, reloading the HDX DSR did the trick Thanks for the help. 1 Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted July 6, 2015 Share Posted July 6, 2015 Out of curiosity, how often is the HDX DSR updated? Would it not be feasible to make an HDX DSR module which is built using EEPROM (or flash ROM, for that matter?) Quote Link to comment Share on other sites More sharing options...
+InsaneMultitasker Posted July 6, 2015 Share Posted July 6, 2015 Out of curiosity, how often is the HDX DSR updated? Would it not be feasible to make an HDX DSR module which is built using EEPROM (or flash ROM, for that matter?) Fred seems to update as fixes and features are available. If the HDX DSR operates similarly to the IDE and Horizon DSRs, some of its RAM is used for internal operation of the device. Quote Link to comment Share on other sites More sharing options...
+Vorticon Posted July 6, 2015 Author Share Posted July 6, 2015 Low level serial and parallel access can be accomplished without the EPROM or DSR code. On the other hand, named devices such as "PIO" and "RS232" and routines such as the Circular Interrupt Buffer (CIB) do require a DSR. Fred's HDX DSR is loaded into RAM (and IIRC is split into two 4k banks). My bet is that the DSR has been partially or completely overwritten or corrupted. If you have not tried reloading the DSR into the RS232 I would try that first. Unfortunately, DSR corruption is a downside of the HDX, IDE, RAMdisks, and similar devices without a fully write-protected DSR (i.e., EPROM). Yeah, I get intermittent DSR corruption with my IDE card, a fact which makes it far less reliable than it should be. I hope that with the planned re-design of the IDE card, the DSR will reside in an EPROM instead... Quote Link to comment Share on other sites More sharing options...
+InsaneMultitasker Posted July 6, 2015 Share Posted July 6, 2015 Yeah, I get intermittent DSR corruption with my IDE card, a fact which makes it far less reliable than it should be. I hope that with the planned re-design of the IDE card, the DSR will reside in an EPROM instead... Same thing happens with my IDE card. I pulled it from my system after one particularly annoying stretch though I plan to try it again with Fred's latest DSR. Perhaps the planned redesign can review whether or not there is some modification that would help, similar to how the Horizon 3000 boards were 'corrected' at one time. Quote Link to comment Share on other sites More sharing options...
+Schmitzi Posted July 6, 2015 Share Posted July 6, 2015 I think the IDEDSR11 is very stable. At least, it seems to be. Had no problems up to today. At the moment I am using this PQI-Disk-On-Modules Quote Link to comment Share on other sites More sharing options...
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