jacobus Posted April 9, 2011 Share Posted April 9, 2011 I picked up a 130XE and XF551 tonight - a bit dusty but they seem to work perfectly. Both have some interesting mods - the 130 has a red and green LED over top of the SIO port. During IO operations they flash in sync with the data transfer. Cool stuff! I believe the system has also been upgraded to 256K. Can anyone confirm this, and additionally are the various wires and extra chip part of the RAM upgrade or is it for something else? Additionally can any tell me what (ie compatibility wise) this memory upgrade is? RAM Upgrade Flashy Light Generator Mystery Mod? The XF551 has a red LED mounted below the regular drive LED. When the drive is on, it lights up constantly. I'll post interior pictures tomorrow. Quote Link to comment Share on other sites More sharing options...
Rybags Posted April 9, 2011 Share Posted April 9, 2011 RAM upgrade looks to be a +256 for 320 total. So you should in theory be able to try the Numen demo and file version of Bomb Jake. Such upgrades aren't just plug and play, so you have extra wiring at various points to support it. XF551 - extra LED on disk drive is usually integrated into a write-protect override switching system. But of course a switch is needed there. SIO LEDs - probably one is connected to COMMAND and will flash briefly once per disk operation. Other might be DATA OUT. Try doing a CSAVE - don't worry about connecting a cassette player. See if one of the LEDs lights up while the blocks are written. Quote Link to comment Share on other sites More sharing options...
BillC Posted April 9, 2011 Share Posted April 9, 2011 I picked up a 130XE and XF551 tonight - a bit dusty but they seem to work perfectly. Both have some interesting mods - the 130 has a red and green LED over top of the SIO port. During IO operations they flash in sync with the data transfer. Cool stuff! I believe the system has also been upgraded to 256K. Can anyone confirm this, and additionally are the various wires and extra chip part of the RAM upgrade or is it for something else? Additionally can any tell me what (ie compatibility wise) this memory upgrade is? RAM Upgrade Flashy Light Generator Mystery Mod? The XF551 has a red LED mounted below the regular drive LED. When the drive is on, it lights up constantly. I'll post interior pictures tomorrow. The 74LS14 inverter is connected to Data Input, Data Output, Ground and +5V/Ready, to drive the R/G LEDs. There was also a wire connected to pin 12(+12V on 400/800 only, N/C on the rest) at one time. Quote Link to comment Share on other sites More sharing options...
sloopy Posted April 9, 2011 Share Posted April 9, 2011 looks like a plain 320k XE mod... the 'mystery mod' thing is the mux that selects the extra ram... if you follow that wire/resistor coming off the 74x158 it should go to pin 1 of the 41256's... XF551, stock didnt have a power indicator, so many people inadvertently left them on, alot added their own power indicator for this... sloopy. Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted April 9, 2011 Share Posted April 9, 2011 Pics 1 & 3: The venerable Scott Petersen 320k XE upgrade. Pic 2: That's an ass-rig.. I'd remove it if I were you. And I'd also remove all those green filter caps to the left, and lower right of the SIO port.. The FCC made ATARI put those on there to reduce "RF noise", but all they REALLY do is cause data errors with the XF551 and with any high-speed SIO device.. What the ass-rig is doing is this: Any time DATA IN or DATA OUT goes low, that 74LS14 inverts the signal and turns on the LED. Basically, its a crude as hell "activity light" for the SIO port.. (to add a power indicator to the XF551, just hook an LED and a 220ohm resistor in series, from +5v to GND somewhere inside the XF551).. Quote Link to comment Share on other sites More sharing options...
mimo Posted April 9, 2011 Share Posted April 9, 2011 (edited) RAM upgrade looks to be a +256 for 320 total. So you should in theory be able to try the Numen demo Would need to upgrade to PAL to do that test though Edited April 9, 2011 by mimo Quote Link to comment Share on other sites More sharing options...
jacobus Posted April 9, 2011 Author Share Posted April 9, 2011 Thank you to everyone who responded! Despite having over 40 Atari systems, this is my first with a memory upgrade! SIO LEDs - probably one is connected to COMMAND and will flash briefly once per disk operation. Other might be DATA OUT. Appears to be DATA and COMMAND. Pic 2: That's an ass-rig.. I'd remove it if I were you. Unfortunately the person who rigged it up (Mr. Assman I presume ) drilled holes in the top of the case for the LEDs - I think it would look worse to remove them. And I'd also remove all those green filter caps to the left, and lower right of the SIO port.. The FCC made ATARI put those on there to reduce "RF noise", but all they REALLY do is cause data errors with the XF551 and with any high-speed SIO device.. Do I need to replace them with anything or just snip? Would need to upgrade to PAL to do that test though I think I'll leave that to the next owner... Thanks again! Quote Link to comment Share on other sites More sharing options...
+orpheuswaking Posted April 9, 2011 Share Posted April 9, 2011 For the caps, just snip... Quote Link to comment Share on other sites More sharing options...
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