MEtalGuy66 Posted January 5, 2017 Share Posted January 5, 2017 Actually, Kyle's pictures are correct and the guide on Steve Cardens website is wrong. This is the correct way: 6 Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted January 5, 2017 Share Posted January 5, 2017 Has anyone ever cracked open their USD RAM stack just to see whats in there? Quote Link to comment Share on other sites More sharing options...
Bryan Posted January 5, 2017 Share Posted January 5, 2017 Tom Harker told me it's 2 6810's. 1 Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 8, 2017 Share Posted February 8, 2017 Actually, Kyle's pictures are correct and the guide on Steve Cardens website is wrong. This is the correct way: I just made this discovery myself while researching to do a USD upgrade. Steve's site was the first I looked at and the extra clipped pins, bottom 11, top 12, didn't make any sense because they leave several chip selects floating. If this does work, it would have to be accidental. I then found this thread and what you and Kyle22 did would properly map both RAM chips without any floating CS's. This is the way I'll be doing mine. Thanks for posting the pics! 2 Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 11, 2017 Share Posted February 11, 2017 I just finished my homebrew US Doubler install and it works perfectly! I did my RAM mod as shown above except I tied top pins 14 & 15 together instead of running the 2nd wire across the chip. I love the sound of those fast reads! 1 Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted February 11, 2017 Share Posted February 11, 2017 I'll stick with the proper stack and wiring in kyles picture... 1 Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 11, 2017 Share Posted February 11, 2017 I'll stick with the proper stack and wiring in kyles picture... ??? Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 12, 2017 Share Posted February 12, 2017 I'll stick with the proper stack and wiring in kyles picture... Do you understand that what I did is functionally identical to Kyles? If you were to stick our two ram modules in a black box, you would not be able to tell the difference. Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted February 12, 2017 Share Posted February 12, 2017 Actually, Kyle's pictures are correct and the guide on Steve Cardens website is wrong. This is the correct way: I do like nice clean soldering and neat wiring, nice upgrade there Metal....Same with Kyle. 2 Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted February 12, 2017 Share Posted February 12, 2017 Heh... this project, like most other things in life at the moment, has clearly not escaped the attention of the all-seeing f**k-up fairy. Lol...I know that bloody fairy, seems to spend quite a time in my gaff Quote Link to comment Share on other sites More sharing options...
+Larry Posted February 12, 2017 Share Posted February 12, 2017 Can someone briefly explain the theory of how this stacking of the chips works? (I do have a pinout of the 6810's.) -Larry Quote Link to comment Share on other sites More sharing options...
ricortes Posted February 12, 2017 Share Posted February 12, 2017 BTW: IMNSHO DON'T cut the pins. I stick a small screw driver between the pin and plastic and bend it out like a wing. For me, slightly less chance of heat killing the chip with heat soldering on the leg 2:44 and makes it a little more reversible. Larry, I hope someone explains it better then I can. I actually saw an internal ICD note/memo/blurb on the upgrade but that was ~25 years ago. Let me say up front that the 6810 is an amazing chip in the number and versatility of the chip select pins. They were really designed like you would build a system with only them and them all over the memory map. This was combined with the penchant for cheap assed hair brained design at Atari/Tandon where if it didn't hurt you or saved money, you didn't bother to design memory maps in an orderly fashion. So if you look at the memory map for the 1050, you will see all kinds of holes in the memory map and mirrored locations. The 6810 has both CS and !CS pins. Mostly what is done is a !CS line is used on the CS line of the second 6810. Kind of busy this morning so accuracy may be off and detail for sure : These lines are typically tied to address lines to select the chip. For instance if you tied the CS of one to A15 and the !CS line of the other to A15, one chip would only appear when the A15 line was active i.e. memory locations >$7FFF while the other would appear at all locations below $7FFF. All the other chip select lines could be tied to ground or 5V and they would be mirrored every 128 bytes. Note that this would need no other decoding chips. But typically in a 6507 or 6502 system, you need ROM in high memory so lower then A15 address lines would be used. In a 6507 system, only 8k address space and the entire top 4k is used by the ROM. If you look at the 1050 map https://www.atarimax.com/jindroush.atari.org/data/ahard/mmap_1050.txtyou will see there are quite a few holes. i.e. nothing from $300 to $37F is not used by anything. It is into one of these holes ICD mapped the second 6810 using the chip select lines. f 1 Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 12, 2017 Share Posted February 12, 2017 The gist of it is that address line a9 is used to select between the top and bottom RAM chips. Address lines a7,a10 and a12 need to all be 0 to enable either chip. The result is bottom chip is mapped to address $0000 with mirrored addresses $0100, $0800 and $0900. Top chip is mapped to $0200 with mirrors at $0300,$0a00 and $0b00. The top chip pin 10 (cs0) was cut and connected to the bottom chip pin 14 (~cs4) which is address line a9. cs0=1 enables top, ~cs4=0 enables bottom. The top pin 14 (~cs4) was cut to disconnect it from a9. It only has to be connected to any other inverted (~) chip select. So connecting top pin 14 to pin 11 (~cs1) or pin 12 (~cs2) or pin 15 (~cs5) will work. They all have to be zero to enable either chip. pins addr bot addr top cs0 10 ~a12 a9 - wired to pin 14 bot ~cs1 11 a7 a7 ~cs2 12 a12 a12 cs3 13 r/w r/w ~cs4 14 a9 a7, a10 or a12 wired to pin 11, 12, or 15 ~cs5 15 a10 a10 2 Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 12, 2017 Share Posted February 12, 2017 BTW: IMNSHO DON'T cut the pins. I stick a small screw driver between the pin and plastic and bend it out like a wing. For me, slightly less chance of heat killing the chip with heat soldering on the leg I'm a little paranoid about heat so I used an alligator clip on each leg as I soldered it. 1 Quote Link to comment Share on other sites More sharing options...
+Larry Posted February 13, 2017 Share Posted February 13, 2017 Thanks, guys! -Larry Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted February 13, 2017 Share Posted February 13, 2017 I'm a little paranoid about heat so I used an alligator clip on each leg as I soldered it. Do you use a temperature controlled iron or a standard set wattage iron, what wattage do you use? I personally used a 15 or 18w antex and never had a heat / track removal etc type issue, anyway, better to be safe than sorry.. Quote Link to comment Share on other sites More sharing options...
re-atari Posted February 13, 2017 Share Posted February 13, 2017 Do you use a temperature controlled iron or a standard set wattage iron, what wattage do you use? I personally used a 15 or 18w antex and never had a heat / track removal etc type issue, anyway, better to be safe than sorry.. I agree with you, Paul. Especially with XE boards you simply cannot be too careful, the traces on these are so easily damaged. I fear 18W might be a bit underpowered for soldering/desoldering +5V or GND planes, though. Usually these are quite large surfaces that quickly drain the heat from your soldering tip, an 18W iron might not be able to keep up with the pace and maintain the required temperature. That's when lifting a trace becomes a real threat. In my experience, the shorter you need to heat up a soldering joint, the safer. I have used a JBC 24W soldering iron for the last 25 years, just a standard type, no temp. control or anything fancy. IIRC it's a Spanish brand. This one has served me well all this time, it even still has the original tip! They don't make 'em like this no more. Having said that, lately I have been looking around for a more advanced replacement, one with temp. control and removable tips. I have heared very positive reviews about Bakon 950D soldering stations. These are available on numerous shops on AliExpress for about GBP 30 (or US$ 40). I have been constantly postponing my order, though, as the JBC iron is still going strong, so no personal experience with this one yet. re-atari Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted February 13, 2017 Share Posted February 13, 2017 Always wanted a temp controlled iron but was too lazy to buy one while at Maplin (could borrow the works one) but these days I do no soldering although I do have to recap an Amiga 1200 at some point, hoping the arthritis holds up Sounds like the JBC has served you well so no harm in carrying on using it Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 13, 2017 Share Posted February 13, 2017 Do you use a temperature controlled iron or a standard set wattage iron, what wattage do you use? I personally used a 15 or 18w antex and never had a heat / track removal etc type issue, anyway, better to be safe than sorry. It's the old blue Weller temperature controlled iron set at 650F. Nice thing about the temperature controlled irons is they keep up with you so you can work fast but won't overheat if you work slow. It's really a must if you are building moderate quantity's of carts for sale. 2 Quote Link to comment Share on other sites More sharing options...
Bryan Posted February 13, 2017 Share Posted February 13, 2017 Agreed, temp controlled is really the way to go. A standard iron just puts out a continuous amount of wattage like a light bulb. The tip temperature will vary depending on the ambient temperature and how many cooler things you've recently touched it to. An active iron has an element that is more powerful so it's turned on and off by a circuit to keep the tip within a narrow range. This means it gets hot faster and stays hot while you're touching it to things (specified as the 'recovery time'). The fanciest irons (like Metcals) can pump out an incredible amount power when need be but even the cheap stations do a decent job nowadays and there's lots of tips and accessories available. 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted May 3, 2017 Share Posted May 3, 2017 apols for necroboot. I have a 1050 with a USD. the drive boots dos, loads games etc without any problem, but refuses to format. any help/suggestions appreciated Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted May 3, 2017 Share Posted May 3, 2017 Does it also refuse to write to disk as well as format? Error 144? Quote Link to comment Share on other sites More sharing options...
Guest Posted May 3, 2017 Share Posted May 3, 2017 ok so, formatted a dos 2.5 disk on another good drive, written dos files to disk booted this disk in "faulty" USD 1050 successfully boots to Dos menu H - write Dos Files starts process, 1050 "Crunch" noise, then nothing, finally 138 error Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted May 3, 2017 Share Posted May 3, 2017 That indicates your problem is most likely more serious than a bad write protect sensor. I'd check the power supply voltages and look at the capacitors and diodes in the power supply section for signs of failure. I'm assuming all the usual things have been tried (clean head, RPM, etc.). Quote Link to comment Share on other sites More sharing options...
Guest Posted May 3, 2017 Share Posted May 3, 2017 (edited) psu is fine - it's used with other 1050s and 1200xl and all work fine caps look good - no swelling or leaking and nothing getting hot is it worth me trying it with stock ICs? Edited May 3, 2017 by Guest Quote Link to comment Share on other sites More sharing options...
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