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Van last won the day on July 19 2017

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    Midibox SID, Circuit bending, Robots, all things Atari

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  1. Could maybe use RA connectors, ala XE. Not sure where to source the connectors, considering the straight connectors seem kind of rare. Yogi
  2. Oh good point. In fact I had been considering this during playback, but most people want to see something and it helps during debugging. Running headless is done often with chipmusic setups for better timing. Yogi
  3. Thanks Michael. I think I found a ball park comparison for loading speeds of different media http://atariage.com/forums/topic/264720-inflatedeflate-improving-the-speed-of-decompression/?p=3747446 Standard SIO - 1.5K/sec HS SIO - 5K/sec PBI HDD - 50K/sec So if these are close to reality, I should be fine loading from CF to Ext RAM banks Yogi
  4. PDF scans of lots of A8 books: http://www.atarimania.com/documents-atari-400-800-xl-xe-books_1_8.html Yogi
  5. Let me ask you Michael, or anyone, about the CF HDD speed? I'm debating the best handling of a large DRO music file, either direct from CF or pre-loaded into ext RAM. Banking the whole file is the fastest access at runtime, but the down side is the load time but that would be before play back starts. So for a 50-100k file, SIO based media seems prohibitive for pre-loading the RAM banks. Transferring from CF to ext RAM seems like it would cut the load time but if the CF access time is fast enough would rather buffer small blocks during runtime direct from the CF. Background: A DRO file is a log of register writes to an OPL chip. Each entry in the log are two bytes composing either the register number and value or command and value. The commands are delays, either 1mS or 256mS x Value+1. So during play back the main loop could be handling back to back register writes or register writes inter-spread with delays. Over all song timing depends on (register writes + delays commands)+loop/system overhead. Yogi
  6. The input circuit to the regulators is just a bridge rectifier so with a old laptop 18VDC 70W PSU or simular and the switching regulator mod I pointed to, could power both drives. The bridge could be by-passed or left in place, it will pass DC just fine. The Switching regulators have a wide input range, up to 45V, without the heat that a linear regulator would produce. So powering the +5V regulator from +18V is no problem unlike a 7805 that would melt down. Yogi
  7. Well, each 1050 has it's own 12v and 5V regulators so I'm at a loss to say why a single AC/AC converter couldn't feed both, as long as it can supply the total max current for both loads. I mean the Power Company does this 24x7. Not alot of difference then Two 9VAC 3A bricks plugged into the same power strip. About the only thing I would add is a common GND between both drives, but I suppose the SIO cable does this fine. Yogi
  8. After a little searching found this about improving the 1050's efficiency http://www.mathyvannisselroy.nl/Atari%201050%20goes%20green.htm This would allow a wider input voltage to the on-board regulators without the added heat of the linear regulators.
  9. Sure, but you would have to have a PSU that can supply the total amperage for both. It' far more do-able now a days with switching PSU designs that can supply 4-5 Amps and are smaller and lighter then the original PSU bricks. Back in the day you would have to use a very large transformer and Caps. Yogi
  10. Glad to hear you're safe and secure. I've been watching the news and our hearts goes out to the whole area. We've been through a storm or two here on the east coast but nothing like Harvey. Hoping the gulf coast gets back on it's feet fast, clean up and rebuilding seems like it takes forever when you have to live through it. Yogi
  11. I was also thinking this the other day about a dual Pokey set-up Yogi
  12. Would be interested in bare board. A suggestion, add 3 pin header footprints under the DIN sockets to allow panel mounted sockets instead of board mounted DINs. Yogi
  13. You might consider a three position screw terminal like this https://www.sparkfun.com/products/10571The 2.54mm ones should match the existing footprint, the down side is they aren't too robust and the screws can be over tightened/opened and strip. Other option could be soldering xtal leads to a cut down component carrier, https://www.digikey.com/product-detail/en/aries-electronics/08-600-10/A101-ND/4258They are a little spendy, but one could be cut to prep both xtals. Yogi
  14. Yes, not liking the overhang of the XEL, just looks sloppy. Clearing the GTIA/Sophia is very do-able. Clearing the other two will have to happen in the Z-axis, either with a cable or longer header pins and/or sockets like with the U1MB. The M-PBI retrofit sound really good to me. Been thinking about placement. Pulling most of the signals from the CPU, would be tight with the KB when raising the CPU. Might consider the area over the DRAMs in a 800XL. May be interesting to incorporate a DRAM-to-SRAM mod on the board also. Just some 'blue sky' ideas Yogi
  15. Agree , was looking over your photos with Sophia installed, just yesterday. The overhang of the XEL 'front/bottom' edge is ~10mm, with the V1.0 board, will be adjusting the M-PBI footprints to allow for this. The next iteration will shrink a bit, at least as much as possible. The header length sets the board width for the most part. On this proto I used a 2x22 footprint for one header, will be reverting to 2x17 headers. The use of the 'Adr Option' headers takes up board real estate also. If the address was locked in, could do away with some of these too. I'm reluctant to consider an SMD design just yet, but it would yield the smallest board. ATM this is a PoC, so getting it running and developing driver softs is the main push. Direct mounting to the M-PBI, the board will at the least overhang the CPU and somewhat the Antic so would interfere with Antonia or VBXE too. With these mods installed, almost the only option is a cable on the M-PBI header. This isn't a major issue for me, stock CPU and Video is fine here. I used an extra long 2x15 header for the M-PBI that adds ~10mm to typical pin length. This has the net effect of raising the attached PCB bottom 15mm above the top of mobo IC sockets but even this may not add enough clearance for the mods. Regardless of my setup, I don't want to close doors for others. Using a ribbon cable extension allows more mounting options but eats more space in the case. For use in a XL or XE, would have to connect with cables anyway so remote mounting should be a design option anyway. Seems alot like 3D chess Yogi
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