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About Nezgar

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    River Patroller

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  1. Perfectly fine. The power supply that comes with the XF551 I believe was the exact same part as that included with the 1050 anyway, which is 9V AC - 31VA, for instance.
  2. I take those socket plastics off in one fell swoop with fat pliers. like pic #3 in this post: https://atariage.com/forums/topic/286826-1050-12v-issue/?do=findComment&comment=4204804
  3. The SpartaDOS Ultraspeed i/o handler kicks in very soon during the load, so it most likely means that is failing due to an incompatibility with the settings on the Sdrive MAX. First, I think theres a setting to turn off "turbo mode" ? That would force regular speed IO. Try lower ultraspeed/turbo divisors - ie A real US Doubler or Happy uses divisor $0A, speedy is $09, or slower but still 2x "warp" speed is $10.
  4. Hmm.. I don't see cassette audio IN as an explicit feature of either the PokeyMAX or PokeyMAX v2. Can anyone confirm if it is supposed to be supported?
  5. SpartaDOS X's COPY /B is for backups (ie copy to an SIO2PC drive) or there is HDSC in the SDX toolkit to make a straight sector copy.
  6. Sounds like maybe the disk in question has some unexpected data in sector 1, some magic identifier that SDX checks for to determine if the disk is Sparta or AtariDOS is not quite right. You could just copy all the files to a fresh formatted sparta disk, use the "BOOT" command on the particular executable that boots (ie X32D.SYS) if its bootable... Then if you're still interested to find out the underlying reason "why" post an ATR of the disk in question here and maybe someone will figure it out.
  7. Awesome stuff! I've just uploaded it Archive.org here: https://archive.org/details/atari-phc-os-jan-1982 This appears to be the same as this one on Archive.org: https://archive.org/details/bitsavers_atari40080mputerTechnicalReferenceNotes1982_20170986
  8. Maybe BEST or B&C might still have stock? I got one of these 7800 game pads from BEST a while back, somewhat rare in North America since they were for the Euro market:
  9. How many disks are you looking at archiving? If you can't find a drive and it's not too many, maybe you can send the disks to someone with an XF551 to try to archive them to ATR files for you. Also, XF DSDD disks are formatted in a way that upgrading a 1050 with a US Doubler would allow you to read at least the first half of a double sided disk.
  10. Here is my US Doubler patched ROM - For Tandon mechs only. After a little research, it turns out the 1050 Turbo had the fastest "standard speed SIO" interleaves for formatting in ED and DD. It's possible this DD interleave is too fast for a real percom drive to read without blowing a lot of revs, I haven't tested that yet. But ED disks formatted by this ROM and used in a stock 1050 or a US Doubler in 1x/standard speed SIO will see a little pickup in performance in 1xSIO/non-ultraspeed mode! Changes: - Track step timing calculated to be the same as Speedy 1050 (Original value $A0, my value $45 - at offset $198) - Enhanced Density format sector interleave replaced with that from the 1050 Turbo: Original US Doubler: 1,3,5,7,9,11,13,15,17,19,21,23,25,2,4,6,8,10,12,14,16,18,20,22,24,26 1050 Turbo ED: 9,18,7,16,25,5,14,23,3,12,21,1,10,19,8,17,26,6,15,24,4,13,22,2,11,20 - Double Density format sector interleave replaced with that from the 1050 Turbo: Original US Doubler: 18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1 1050 Turbo DD: 9,18,7,16,25,5,14,23,3,12,21,1,10,19,8,17,26,6,15,24,4,13,22,2,11,20 (Slightly faster than Percom's!) USD ROM Sector Table Offsets: Single: 89C-8AD Double: 8BF-8D0 Enhanced: 8E2-8FB After some testing of the ROM in Altirra, I programmed it to a 2732, plugged 2 6810's into one of my 6810 doubler PCB's, Moved JP1/3 to JP2/4 and the drive was off to the races! I've wanted a US Doubler ROM with these changes for quite some time. I guess next up is a modified version for WST mech's to incorporate these formatting interleaves. Nezgar-usdblr-Tandon-DDED-fast.rom
  11. With modern memory upgrades like U1MB and tf_hh's 512K upgrades in an XL, they provide true antic access to extended memory (in compy modes) just like freddie provides in XE's. Unless theres something else freddie does?
  12. I think that's pretty consistent for atari's smaller mask ROM's (2K, 4K, 8K) to use an inverted CS/CE signal compared to EPROMs. (ie 2600 carts, 1050 disk drive, 850, etc. ) As opposed to 16K & 32K OS ROM's which were directly swappable. The 1050 has an inverted signal available without extra parts by changing jumpers above the ROM socket. The 810 I believe also has such a signal already available, as there appears to be only 3 jumper wires and 1 trace cut for the Chip/Archiver mod I linked to previously. Hmm.. Maybe a 2716 would only need 2 of those wires.... or put a switch on that wire going to the 6532 to toggle between Rev B / Rev C on a 2732.
  13. Your observations seem consistent with what I've read before. Some previous references to this observation from previous dump attempts: https://atariage.com/forums/topic/279363-the-atari-810-revision-b-rom-has-finally-been-found-dumped/?do=findComment&comment=4041565 https://atariage.com/forums/topic/85478-810-rom-images/?do=findComment&comment=1039736
  14. Yes. (I have some, even 2816 EEPROMs!) Though there currently isn't a 'solderless' way to replace the original 2316 mask ROM with an EPROM - some minor modifications to the ROM socket pinout are required.
  15. I'll try to get the current measurement from the trimpot for you. Hopefully in the next couple of days. You are correct, this is well established.
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