GDMike Posted November 2, 2018 Author Share Posted November 2, 2018 How many? Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 2, 2018 Author Share Posted November 2, 2018 cool..good to know! thx Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 2, 2018 Author Share Posted November 2, 2018 (edited) Yeah, I saw this card on eBay for a couple hundred, I knew it was a gamble cause we're talking about a 40 year old piece of technology, ok, plastic- there I said it.. BUT knowing what this card can do in the PEUnit and it's access time compared to a floppy,plus I just love it! yeah I Know the newer NANOs are out and I sold mine to get this hrd, getting it back to a working hrd and a working PEB, I can take advantage of the SAMs card and Tforth. What's more cooler? Oh besides the F18A upgrade...I'm still waiting on that one. Edited November 2, 2018 by GDMike 1 Quote Link to comment Share on other sites More sharing options...
sparkdrummer Posted November 2, 2018 Share Posted November 2, 2018 I have these two Horizon ramdisks I'd like to put back into service. The first one is a 2000 I think. The second one a HRD+? They both need the Horizon change #3. I'd also like to expand them to thire max capacity, unless they already are. Anyone out their willing help an old fart out? My eyes just aren't good enough for me to do delicate work anymore. Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted November 2, 2018 Share Posted November 2, 2018 The first one is, as you suspected, and HRD2000, and the first one is an HRD. Note how low the serial number is on that board. . . Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 2, 2018 Author Share Posted November 2, 2018 Sweet! I'd love to see these up and running too! If you ever decide to part with them, definitely let me Know, but I don't know myself how to upgrade them. Hopefully someone will step up that can get it done for you. They are sweet! Good luck to you sir! You're in the right place! Quote Link to comment Share on other sites More sharing options...
Opry99er Posted November 3, 2018 Share Posted November 3, 2018 Here's my "Chicago" RAMDisk. The voltage regulator heats up as soon as power is apppied... suck. It is beautiful though. 1 Quote Link to comment Share on other sites More sharing options...
+InsaneMultitasker Posted November 3, 2018 Share Posted November 3, 2018 I always liked that version/color of board. Nice ! 1 Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 3, 2018 Author Share Posted November 3, 2018 oooh...that dont look like the right Voltage reg...isnt that a 5VDC? 1 Quote Link to comment Share on other sites More sharing options...
Opry99er Posted November 3, 2018 Share Posted November 3, 2018 (edited) I believe other than the battery, all components are original to the board. Edited November 3, 2018 by Opry99er Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 3, 2018 Author Share Posted November 3, 2018 I'm almost willing to bet money that it should of been a NTF960. 10-30 vdc 1 amp. Or similar. But maybe one of the pros can answer better when they see your message. Quote Link to comment Share on other sites More sharing options...
+InsaneMultitasker Posted November 3, 2018 Share Posted November 3, 2018 The regulator output of 5v is correct and appropriate. 1 Quote Link to comment Share on other sites More sharing options...
wileyc Posted November 3, 2018 Share Posted November 3, 2018 The regulator output of 5v is correct and appropriate. ... which puts me on a design tangent track. The voltage output as measured from the output pin against board ground is actually +5.7VDC (on the HRD+ at least, IIRC the other variants too). This is done to compensate for the voltage drop across the battery backup protection diode, and is done by connecting the 7805 ground pin to ground through a same-spec diode. It's a neat trick to make a non-adjustable VR output a custom voltage, but drop-in switching replacements for the 7805 don't like it (definitely the CUI, maybe the Murata too). The Right Thing To Do is to replace the 7805 with, say, a switching LM317 workalike and set it for 5.7. That would require reworking the board, hence my silence when Opry99er mentioned the immediate heat concern. If folks want, I can speak to the germanium diode wired-OR mess in a future post. End design tangent 2 Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 3, 2018 Author Share Posted November 3, 2018 (edited) I saw some new switching ps on one of the posted boards. I love it. I didn't mention it, cause I know or I've heard about this ground issue.. so I doubt I could get one...hmmmmm?? Edited November 3, 2018 by GDMike Quote Link to comment Share on other sites More sharing options...
wileyc Posted November 3, 2018 Share Posted November 3, 2018 (edited) I saw some new switching ps on one of the posted boards. I love it. I didn't mention it, cause I know or I've heard about this ground issue.. so I doubt I could get one...hmmmmm?? Well, you could try the Murata replacement for the 7805 and replace the diode to ground with a wire. That'd run the whole board at +4.3VDC, though, and I'm not sure the TTL parts on your board would like that. My testbed is 100% CMOS, so it interoperates with the rest of the system okay (the logic highs are within TTL tolerance, at least) but for the time being go with a high-current 7805 please. (the Murata datasheet has interesting disclaimers when used in a circuit like the HRD+: "The output is not intended to sink appreciable reverse current", for example Edited November 3, 2018 by wileyc Quote Link to comment Share on other sites More sharing options...
+dhe Posted November 3, 2018 Share Posted November 3, 2018 Opry99er, Thanks for the memories, it was a nice looking board and the guy that produced it Mike Ballumm (sp?) - was very knowledgeable. I was at the Chicago fair when these where released. Bud Mills about stroked out. I think the source of contention was that the original Ron Giles board and software was public domain the enhancements the Bud Mills service made where not. d. Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 3, 2018 Author Share Posted November 3, 2018 Yup, I've got one of those. Cause I am replacing the other. I read up on the power req for cards in general, with the exception of the RS232 I guess, most if not all cards have the 7805. I just thought it was too little Power for piggybacking chips and other harware. But to my surprise It was not the case. Also noting, running through the diode is strange to me too, but again, no diodes blown because if it I guess. As I dig deeper into the schematic, maybe I'll see more than I do now to help me understand it. Thanks for clarifying that for power req, 5.7 is fine. Quote Link to comment Share on other sites More sharing options...
wileyc Posted November 3, 2018 Share Posted November 3, 2018 *laugh* I learned a long time ago in Shenzhen: when schematics are published, the whole shebang is public domain. Keep your IP close and safe if you don't want it cloned. the original Ron Giles board and software was public domain the enhancements the Bud Mills service made where not. Quote Link to comment Share on other sites More sharing options...
wileyc Posted November 3, 2018 Share Posted November 3, 2018 Yup, I've got one of those. Cause I am replacing the other. I read up on the power req for cards in general, with the exception of the RS232 I guess, most if not all cards have the 7805. I just thought it was too little Power for piggybacking chips and other harware. But to my surprise It was not the case. Also noting, running through the diode is strange to me too, but again, no diodes blown because if it I guess. As I dig deeper into the schematic, maybe I'll see more than I do now to help me understand it. Thanks for clarifying that for power req, 5.7 is fine. Out of curiosity, how much EE chops do you have? I don't know what level I should use when talking hardware here. Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 3, 2018 Author Share Posted November 3, 2018 Do you mean in static ram alone? Quote Link to comment Share on other sites More sharing options...
Opry99er Posted November 3, 2018 Share Posted November 3, 2018 Opry99er, Thanks for the memories, it was a nice looking board and the guy that produced it Mike Ballumm (sp?) - was very knowledgeable. I was at the Chicago fair when these where released. Bud Mills about stroked out. I think the source of contention was that the original Ron Giles board and software was public domain the enhancements the Bud Mills service made where not. d. Interesting. I'd love to hear more. Will you be at the Faire next weekend? Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 3, 2018 Author Share Posted November 3, 2018 7805 done Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 3, 2018 Author Share Posted November 3, 2018 Heatsink Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 3, 2018 Author Share Posted November 3, 2018 Heatsink Quote Link to comment Share on other sites More sharing options...
GDMike Posted November 3, 2018 Author Share Posted November 3, 2018 Heatsink Quote Link to comment Share on other sites More sharing options...
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