xrbrevin

it cannot hurt to tweak the stepper motor position - the mounting screw holes are slotted you dont need a special device, just a screwdriver - try setting it a degree or two at a time fore or aft. if it doesnt improve, go the other way. you can always revert to the original position as there will be 'chafe' markings on the slotted mountings. i had to do it to one of my 1050s and i managed to find a 'sweet-er spot'. its not complicated or risky so have a go!

you could put the indus mech into a tandon 1050 and cross reference the settings using the 1050 diag disk conversely, take a working mech out of a 1050 and put it into the indus

hang on, i think it might be an ultravideo xe mod... it is, oh well.. i'll leave it in back to the drawing board

cheers for the advice. im also intrigued to know why someone may have changed these resistors. I'll research their purposes to get an idea. im using sams computerfacts but im struggling for a keyboard to input the basic audio command! the one i have has intermittent mylar issues so unfortunately ive not been able to follow the guidance to the letter. i have traced the signal from POKEY pin 37 and the associated components are within their ratings - 1 resistor (R3) gave no rating so i replaced this (the blue one on the left in the image). i ought to re-check just to verify the results tho. i think i should get a logic probe really, its worth having one anyway

fitted 1x of the caps (C50) but still no sound however, i spotted an anomaly - 3x resistors are blue: see image (ignore the one on the left, i fitted this the other day). i metered them up and they are all 75ohm! (someone's been meddling....) they should be: R53: 100ohm R204: 47ohm R202: 180ohm so there is a possible solution - ive ordered new ones. fingers crossed!!

my 65xe gave me 'the red/brown screen of contempt' but it turned out to only be the MMU so i'd recommend also checking that ive also known bad OS ROM, CPU, freddie or RAM to cause the same. swapping the chip for a known good one is a simple way to check if you can? best of luck

sadly not...

crikey, i bet all youve heard for days is: "zeek-zeek-zeek-zeek whirrrr etc" looking really good tho!

ive ordered the 4x radial electrolytic caps, if it doesnt work then i'll donate guts from this board to a 65xe board to make it 128k and keep the rest for spares make or break

Hi, I hope someone can assist, i have a shabby 130xe that is reliable but it has no sound out of the monitor socket (just thought: i will have to try the RF modulator..) anyhoo, heres what ive done so far: desoldered pokey - it works fine in my 600xl desoldered LM358 (U1) - also works fine in my 600xl. metered up all the associated resistors (as specified in sams computerfacts) - R3 showed no reading. great! - or so i thought. i replaced it but sadly no change... desoldered 2x electrolytic caps to isolate out the SIO audio in: C22 C18 - still no audio so i put them back in. confirmed continuity between LM358 (U1) and modulator left pin, associated resistors: R8 R10 etc and monitor port audio pin - all ok I get a voltage from pin 37 of the pokey and there is continuity from here to capacitor C17 im wondering if an electrolytic cap is bad.. will check modulator audio now and report back ..no audio via modulator :/

highly likely! haha

this site has good quality disk images with the latest games on: http://www.mushca.com/f/atari/index.php?idx=9

thanks for the info, they can be fickle these things.. thus far the Atmel chip is working ok in a 130xe so I will get some more, they are only £1 each new on the fleabay and they are electrically erasable instead of UV i like the HISIO with cold reset and reverse option basic but also like to keep the stock XL/XE too so its a good solution ive given up on making an MMU because the i couldnt get the .jed files to work - the GAL seemed to program ok but the computer did not boot. I found an MMU from a spares supplier for reasonable money instead

try fred at: www.rewindgames.eu he's a really helpful, nice guy! they have loadsa spares and shipping is cheap too

i use that USD rom image that you recommended - the one with minimal stepper motor noise and quick spindown ive done 3 drives with it now and intend to do a 4th but the drive worked briefly then developed a mystery fault :/ - its keeping my brain exercised for sure! hehe

a comprehensive resource - thanks for finding it i never knew there was a tools disk and range of software for the USD - i downloaded then immediately!

ive no experience of writing to SIO2SD im afraid I would recommend SIO2PC and a drive emulator software like aspeqt you can then load a sector copier like mycopyr or copy2000 and copy from your disk drive to a virtual drive on the PC this will create an ATR file from your floppy disk that you can store on your PC

v. impressive !

Just thought i'd post a pic of my UAV Rev. D in my 600XL success!

its not a big deal, just an observation. i never knew there was a link between the OS and MMU until now. update for my post above - the TMS 27C128 has just perished again. the computer boots straight to self memory test and now both ROM banks are red! time to bin that chip methinks..

The TMS27C128 is working after a heavy UV and re-burn - it has the hi speed SIO / reverse option / hard reset OS ROM running nicely now

erk that sounds a bit dodgy! anyhoo, it was the MMU - the bad one from the 65xe caused the same brown screen when plugged into the 600xl and conversely, the 65xe works normally with the MMU from the 600xl! interesting to find out that sys check II reports OS ROM failure when only the MMU has failed i read that a pal 16L8 can be made into an MMU but my minipro TL866 only lists GAL devices.... i have a PAL16L8 and it appears to burn when i set it to GAL16V8 but only if i untick verify! sadly the machine just does the brown screen fail are you aware of a workaround to burn the PAL chip?

never heard of that trick but alas it didnt alter anything all continuity checks ok with the OS socket - address and data buses, vcc, vss etc the MMU receives a line into pin 15 from the OS ROM pin 20 & 22 called "OS". next job is socket the MMU and swap it out

hi thanks for your replies, the TMS27C128 now boots straight to self test and the second block is showing red. I'll give it an extra long dose of UV and try again because it did work before in the 600xl. none of the stock ROMs are defective (which is nice), my problem now is the 65xe has a fault when reading the OS and i get the trademark red/brown screen. I will do some continuity checks on the OS socket next - time to warp to jerzy sobola site (again) and warm up the mull-tim-etter...

The 65xe i tried it in has other issues... i tried the above 27C256 in my 600xl and it works fine - thanks for your help! i then tried the 65xe stock OS ROM in the 600xl and it is also fine. None of the ROMs work in the 65xe - i can only get it to work when i plug in the sys check II so i will fit the switched EEPROM into the 130xe as originally intended - the switch will fill the hole nicely now i have a 65xe ROM reaing problem diagnostic on my hands!! any suggestions will be gratefully appreciated