Lumpy

Thanks for the response and I understand what you are saying regarding old software and new hardware. I started with the TI and although I got a lot of enjoyment out of it while building a substantial system back then I eventually went to the darkside. In the last couple years I have stepped back into the TI arena, more for nostalgic reasons and am intrigued by what is still available and the support for it some 40 years later. I am quite familiar with DOS so I will have to investigate Force Command further since it has some similarities as far as command lines go. I will have to learn DM2K better as well.

I finally got my TIPI PEB setup and have a small issue that I hope someone can shed some light. My system has a TI RS232 and a TI disk controller that has the modified ROMs to allow 80 track drives on devics DSK2 and DSK3. DSK1 is a DSDD 1/2 height 360K drive, DSK2 is a Gotek setup with Flash Floppy and DSK3 is and external 720K 3.5" drive that is not currently connected. The memory card is a Super AMS 1 meg card and there is also a 2 meg HRD4000 at CRU 1200. The HRD is setup with several drives starting at DSK4. In this configuration everything works fine and I can use DM1000 to format, catalog or copy files to any of the physical or RAM drives. I installed the TIPI at CRU 1000 and set up the wireless but with no drive mappings. The TIPI has a DSR dated 2023-08-04 and the PI is 3.25. With the TIPI installed I get an I/O error trying to do a directory or any other request on DSK1 or DSK2 but it works fine with DSK4 and up when using DM1000. If I use DM2K it will do a directory just fine and saving or retrieving a file from DSK1 in BASIC works fine. I tried moving the CRU of the TIPI to 1400 but it made no difference. Is there an issue with DM1000 and TIPI? I can probably switch and use DM2K but I find the interface easier with DM1000. TIA

Just tried it again and still working so looks like U7 was the culprit. Once again, thahks to all who offered help and suggestions.

Thanks for all the suggestions. I think I may have fixed the issue. Although I am by no means an electronic technician, I can do some basic tracing on a schematic so last night I was looking through the HRD schematic and noticed that U7 (74LS156) was connected to D4-D9 that had been suggested earlier as a possible issue. So this morning I changed out that IC. Before I tested this change I downloaded the DSR dump program with the intention of running it but when I powered down the PEB and then back on, the ROS was still loaded! I then powered down the PEB and let it set for ten minutes and tried again and it was still working. I will do some more testing but looks like I may have had a bad chip, although it was new. Here's hoping that this was the problem and if so, I appreciate all the suggestions and help.

Thanks. I will give this a try shortly.

Thanks for the idea to dump the DSR space. I can attempt to do that but I am not sure what program I should be looking for. I checked WHTech but couldn't find anything there.

Thanks for the reply. I checked the voltage coming out of the battery holder and it measured 4.7V and at CR13 and it measures 4.34V. Also it shows 4.34V at VCC on all of the memory chips including 32K chip containing the ROS. I think it is an issue as Ksarul says with signal problems when switching from the PEB power to the battery power. I checked and replaced CR4-CR9 but still the same problem. Not sure where to go now.

I assume you are referring to Q2? I believe Q1 is just switching the front LED and it is working. Q2 has the leads marked on the transistor itself. The emitter is going to ground the base goes to R2 so I assume the collector is going to the correct spot as well.

I checked the 32K RAM and it was a Hitachi HM62256ALP-12. I didn't check if this was a low power version or not but the previous board I built had a different manufacturer's chip. I looked and I had another of the same so I installed it, a MOSEL MS62256L-10P. Tested and same issue. I then looked at the diodes and I guess I mixed up the ones you sent with my stock of 1N34A diodes and I had installed them, I removed the 1N34A's and installed the D9K units that you had sent with the white lines to the center. Tested again and same issue. It works 100% as long as I don't power down the PEB. I only have to power the PEB down for 20 seconds and the ROS is gone completely.

I have a Finalgrom.

Here's a couple pictures of the front and back. Hard to see the switches but SW3 is on (CRU 1200) and this is the only HRD4000 in the PEB. There is just the standard TI RS232, TI 32K and TI Disk Controller in this PEB as well. The other HRD4000 is in a second PEB by itself.

I just checked all the remaining HM628128 RAM chips and there is 4.34 volts on all of them as well as U9.

I purchased a couple HRD4000 PCB's from KSARUL and after securing the parts I built up the first one with 2 meg of memory. The board loaded ROS842 with no issues and works as it should. I finally got around to building the second one and it loads the ROS842 as well and I can save and load files to it as it should. The autostart menu works but I have an issue with it retaining both the ROS and drive contents when I turn off the PEB. I am using standard AAA batteries and have the JP6 jumper installed as well as R6 removed and CR13 in place. I checked the batteries for volatage and they are fine. CR13 checks out fine as well. I checked the voltage on U9 with the batteries installed and the board removed from the PEB and it reads about 4.5V. I swapped out U9 with another and the same problem. I went over the board several times looking for shorts but everything looks fine. Any ideas where I should be looking now? Thanks P.S. I forgot to add that the MEGTEST passes.

ROS is 8.42c and using the DM1000 and Menu program included with that distribution.

I was using DM1000 included on the ROS disk. I just tried it with DM2K and it reports 3198 free and 2 used. I'll try DSKU as well. Thanks for the help.

I finally got all my parts in to complete one of my HRD4000 cards and for the most part it appears to be working correctly. This card is built as 2 meg card and I have a question about used sectors. I run the CFG program and load the ROS which loads up with no errors. I then go to format the disks and I can setup and format three large disks, two of 3200 sectors and the remaining one is 1784 sectors if I recall correctly. If I then go to a disk manager program and catalog the disks, it shows a number of used sectors on all three even though the disks are blank. The first and second 3200 sector disks show 2703 sectors free and 497 used while the smaller 1784 sector disk shows 1033 free and 751 used. I suspect this has something to do with the large size but I am not sure. Do I need to make more smaller drives?

Yep.

It's gone.

Anybody out there that could use this? It is a clip that snaps over a 64 pin IC like the TMS9900 and brings the pins out to a 64 pin header. Free to anyone who wants it. Just pay the shipping.

https://www.arcadeshopper.com/wp/store/#!/32k-sidecar-memory-expansion-KIT/p/81611057/category=28272181

Before changing any internal parts, try cleaning the edge connector contacts. I had one that was not recognized and I cleaned the contacts with a pink pencil eraser and it works fine now.

Family always takes priority and vacation is important for mental health so take care of those things. As I said, I am very interested in this project but i can certainly wait until you are ready.

Any update on your progress? This is a very interesting project and I am hoping to purchase a PCB if/when you work out the bugs and hopefully offer the boards for sale.

Just had this problem and someone suggested checking the indexing sensor on the drive. In my case the bracket holding the sensor had broken and the sensor moved out of position. I secured it back in place and it works fine now.

Can you post a picture of the actual internal switch? I think I may have some switches that could be used as a replacement. I remember seeing a picture of one but the PEB's I have now are the newer toggle switch variety.