tf_hh

4464 is just another name for the same thing: 256 Kbit DRAM organised in 64 K x 4 Bits. Some manufacturer uses 4464, some 41464 and for sure there are more in the wild. Everything starting with 250 ns or less is fine.

This inductor is in the path for drive motor power and burns sometimes over the years, have seen this a several times. Mostly heavy used drives, so I strongly suggest to change all electrolytic capacitors left of L6 also (the four on the left, they´re also in the 12v motor circuit). When such a fresh-up is done, change also the three big caps - 4700 uF is enough each, sometimes Atari uses 6800 uF, but that´s not mandatory. Look at the picture, I mark all caps which I would replace to make the drive fit for the next 20 years I´m not sure that repairing these parts will change the drive RPM, but use the speed pot for adjusting the standard speed of 288 RPM, then the other three should fit, also. Most users report to me "works fine", but a few need adjustment anyway. Jurgen

First: Sorry to read that. Although I test every device carefully, not all faults can be excluded. Could you sent me a picture from the installed version, specially the ribbon cable? When I shipping out the first big batch in 2016, two user sent me similar reports - in both cases the ribbon cable was the source of trouble. One wasn´t correct crimped, the other one... was crimped the wrong way (180 degrees turned). This won´t damage anything, but the read and write signals are routed over the ribbon cable, so the basic functions - read and write data - won´t be successful. Jurgen

Just for the records: This information is outdated (Reminder to myself: I´ve to update manual!!!). Sys-Check always overrides internal memory expansions, so no conflict is given. The only possible conflict would occur, when Sys-Check would used together with the Turbo Freezer and both memory expansions are active. Because Sys-Check uses REF to get access and the Turbo Freezer does it the same way, this would result in problems, when Memory Expansion is switched on at Sys-Check AND Turbo Freezer together. A 130 XE works fine with Sys-Check, the internal 64 KB memory expansion is unused, when Sys-Check´s memory expansion is active.

I´ve also had some XEGS with issues like that. The half of issues I can fix with changing the DRAMsm the other with OS-ROM and MMU. it´s strange... I never must change DRAMs (as long the right power supply was used ) at the Atari 130 XE mainboards using 2 (800XE) or 4 (130XE) DRAM 41464 models, but the XEGS - with same DRAM type - has a lot defects. Also the OS-ROM was faulty some times, in the most cases the MMU (PAL16L8) was defect - typically on or more of the outputs can´t sink, they remain at high level forever. My personal thoughts are, that the XEGS - the last production line - was populated with all the sediments Atari found in their production warehouses

Congratulations, well done with good help from this community This thread, the login screen brings me back to the old times with BBS´s... I think, I will dig in the basement, hope to find my 850, the US Robotics modem and finally hope, it will connect over the actual VOIP fixed line... Are there some real working BBS in the U.S. with real analogue dial-in ports - no telnet etc.? Does anybody has a list? Jurgen

That´s quite easy - but the organisation is strange. ROM offsets: $0000-$1FFF - 8 KB Missile Command $2000-$3FFF - 8 KB BASIC $4000-$7FFF - 16 KB Operating System The MMU is a little bit different from the XL one, it uses the PB6 bit for selecting Missile Command / BASIC and managed the addressline A13 for a working O.S. access. I´ve made an standard XL MMU for usage of standard 16 KB O.S. (so no problems with memory expansions using PB6). Here´s the code: CHIP MMU_XEGS GAL16V8 COMPLEX_MODE A11 A12 A13 A14 A15 MAP RD4 RD5 REN GND REF S5 PB6 ROMSEL OS CI IO BE S4 VCC /S4 = /A13 & /A14 & A15 & RD4 & REF; /S5 = A13 & /A14 & A15 & RD5 & REF; /IO = /A11 & A12 & /A13 & A14 & A15 & REF; /OS = A13 & A14 & A15 & REN & REF /* $E000-$FFFF */ + /A12 & /A13 & A14 & A15 & REN & REF /* $C000-$CFFF */ + A11 & A12 & /A13 & A14 & A15 & REN & REF /* $D800-$DFFF */ + A13 & /A14 & A15 & /RD5 & /BE & REF /* Atari-Basic */ + /A11 & A12 & /A13 & A14 & /A15 & /MAP & REN & REF; /* Selbsttest */ /CI = /A13 & /A14 & A15 & RD4 & REF + A13 & /A14 & A15 & RD5 & REF + /A11 & A12 & /A13 & A14 & A15 & REF + /OS + /REF; ROMSEL = A13 & A14 & A15 + A13 & /A14 & A15 & /BE; BR Jurgen MMU_XEGS ohne PB6.jed

This newer revision of the XE series mainboard has the fix already onboard (routed on the PCB).

OS ROM at PAL XEs are mostly the standard Rev.2 as found in all 800XL (CO61598). So just change ANTIC, GTIA und system crystal (CO16112) to a CO10177 or CO61090 (Atari partnumbers) or any standard crystal with 3.57945 MHz. This frequency is easy to get in PAL areas, too.

Hi, sorry for that - orpheuswaking also report problems. I´ve add an alternative address (see post #1 of this thread) for download, it´s the GMX media space. The website is - sorry - in german only, but it´s easy... just click the file(s) and select "Herunterladen" (german for "Download"). Jurgen

No, the 600XL must have 64 KB already to be fully used. But... if you can wait, there comes a new expansion in the next few weeks - only and specially for the 600XL. Be patient

Please click on the linked PDF file at the end of post one. You will find all infos there

Hi, I´ve made some more new pieces of my (mostly in germany) well-known expansions. If you´re interested, please find all informations below (end of this post)! 512 KB SRAM memory expansion for all Atari XL/XE and XEGS This small PCB (only 5 x 5 cm) enables your Atari XL/XE to watch the newest demos or play the actual homebrew games which requires often more than the 64 KB main memory of the machine. My solution don´t need the drill holes for switches, it´s software configured. After power on, the 512 KB "RAMBO" mode is active. This mode should fit all your needs in 99% of all use cases. For some rare programs you can switch to 256 KB Compy-Shop mode (with seperated ANTIC and CPU access) or switch the whole expansion off. These setting remains active until you power off the computer, a coldstart without power cycling won´t change the setting anyway. The ANTIC needs to desoldered, if it´s not already in a socket. Also the MMU. Just three wires must be soldered, a prepared cable for that is included. This SRAM based 512 KB memory expansion works in all Atari XL, XE and XEGS computers. Mini-Speedy 1050 for the Atari 1050 diskdrive This small PCB sizes only 5 x 5 cm and it´s installation is absolute solderfree. Just remove two chips, cut of four capacitors and plug in the Mini-Speedy 1050 PCB - that´s all! The Mini-Speedy 1050 offers the following features: 1. Highspeed SIO transfer up to approx 76000 bps 2. Real Double Density (180k each disk, 256 bytes per sector) 3. Flawless 8 KByte track buffer with highspeed write by default 4. Works with all known Highspeed SIO routines and any DOS 5. Built-in (just boot your 1050 with open disk lever!) Highspeed-Copy-Program or BiboDOS (needs seperate switch for changing Speedy O.S. selection). Turbo 1050 Replica for the Atari 1050 diskdrive The Turbo 1050, made by B. Engl, is one of the "freakiest" products I know. Just using an EPROM, a GAL (logic chip) and some parts around the Turbo 1050 is a very cool floppy enhancement for the Atari 1050 diskdrive. The power is in the software only! No track buffer, no additional RAM, no CPU with bigger address space. On the other hand, Turbo 1050 can copy more protected games like any Happy 1050! A short brief about the features: 1. Enables Double Density (180k per disk, 256 bytes per sector) 2. Enables Highspeed-SIO up to 70000 bps 3. Has built-in "BackUp Machine" for copying protected disks 4. Parallel port printer interface (not included in this replica) Due to the fact that the Turbo 1050 hasn´t any track buffer the Highspeed-SIO is always used, but really effective only when the disk to be used was formatted using the Turbo 1050. The Turbo 1050 formats disks with a special interleaving, so that these disks can be read at the same speed like all other floppy enhancements with track buffer. How to order You don´t need to show interest - these products are already developed and built, I have some at stock. Please load the following PDF file: http://www.van-radecke.de/STUFF/tfhh_HW_info.pdf If this link won´t work, try this one (same content): https://c.gmx.net/@334647219317637459/l5-Q6dQOQl-nheYIoit9ZQ This PDF file will be regulary updated! So you don´t need to ask "Is there any left?" - just download the file and look to page 2 This "catalogue" also includes my other solutions. Jurgen

PN sent!

PN sent!

Ok, that´s the point I already wrote some posts earlier. Lift one side of the R42, when it´s 4.7K, then this resistor is fine. Also check connection of +5 volt to one side of R42. After that, remove one side of C91 and check voltages again. At last, check the duct of pin 28 from POKEY to the junction of R42/R128 - not that the problem is just a simple defect at the POKEY´s socket...

Hi, First check out if there´s a video interface failure. One way without a scope is to remove the O.S. ROM (or EPROM in your case like it looks) and power on the machine. Without O.S. ROM the hardware I/O area will not be zero´ed and you should get a red/brown display (more red on NTSC, more brown at PAL). If this happens, then video interface is fine. If not, the video interface MIGHT be the source of trouble, but you can test some things with a standard multimeter. Check pin 39 of the CPU, this is the PHI2 clock signal. Reading this pin with a multilmeter should show different voltages between 1.5 and 3.5 volts. If so, then the CPU generates this important signal. If you´re reading below 1 volts or over 4 volts (constant "low" or "high"), then the CPU may defect. Check pin 37 of CPU. When also read below 1 or over 4 volts, then ANTIC, GTIA or main crystal circuit is defect - no system clock frequences generated. Otherwise CPU is bad or something connected to PHI2. More tests, when you really changed _all_ parts (specially the "Delay Line", CO60472), are not useful w/o a scope IMHO. Good luck, Jurgen

The R42 is measured one side up (not connected to anything) with 276 ohms, really? Then it´s defect and should be replaced. Here the path:

You shouldn´t measure the value of a in-circuit resistor. At a minimum, lift one side, so that one side is floating not connected to anything. Now you can measure the resistor and should get something around 4.7K. It´s very, very rare that a small signal resistors went bad without having high current and a short-circuit. In that case you should see something burned :-) And yes, because other connections to that signal (at least POKEY itself) are made, the result of a measure having the resistor installed is not accurate. What do you mean with "open" at DATA_OUT? You get ~zero volts or no connection (if you use the diode tester of your multimeter)? Remember, that there´s a 100R resistor in line - most diode testers will respond up to 20R max. So check connection step-by-step from SIO to one end of R128 (100R) and the other to POKEY. The pull-up resistor of 4.7K is "behind" the 100R resistor (facing away from SIO connector), so I would examine the 100R first. Jurgen

Another update... also the programming (flashing) of The!Cart V2 works now fine on an Atari 400 or Atari 800! I´ve tested it with a full 128 MByte ATR file (took over 7 hours each!), no problems. The Atari 800 need the PHI2 cartridge patch, of course (see here: PHI2 Patch for Atari 800) Owners of the The!Cart V1 version can also use their carts with an old Atari computer, when the CPLD code is updated to the lasted version from Hias and the actual CARTMENU is used. The cartridge won´t fit with a closed cartridge door, but it works

No, not possible to damage anything when VDC is used but VAC is required - the opposite way can damage a lot of things for sure When the power circuit doesn´t really need VAC, then the most devices fed with VAC can also be used with a VDC power supply - the VDC must be 1.4 times higher than the VAC required. So when 9 VDC is used, the effective transformed voltage at the 7805 regulators maybe to low - the computer won´t start. But nothing can be destroyed.

There´s no 12 volts used in a 1200XL. Only the 400 and 800 computers have 12 volts at the SIO connector, all other computer´s not.

Regarding all the points you´ve already checked, IMHO the only reason could be a broken trace OR defect discrete part in line of COMMAND, DATA_IN or DATA_OUT. Do you have a scope? Then it should be really easy to find out the issue. COMMAND line should toggle sometimes to low during "detection SIO sound" after powering on. Also the DATA_OUT line should have some transistions, the O.S. sent "Status" to Drive D1: to test if there´s any. When the display of your SIO2SD doesn´t change during the "buzzing SIO sound", then COMMAND or DATA_OUT is mailfunctioned. Here are the parts to check: COMMAND-Line: R79 (100 ohms) and capacitor C82. DATA_IN: R127 (100 ohms) and capacitor C90. Also R41 (4.7k pull-up to +5V). DATA_OUT: R128 (100 ohms) and capacitor C91. Also R42 (4.7k pull-up to +5V). The caps mentioned are connected to ground. So if the signal is constantly at low level, the corresponding cap should be exchanged (1nF) or removed for test - works also without. If you don´t have a scope, check voltages in idle state. All three lines should have something over +4.5 volts. If not, check all parts listed above. And also examine the traces. Good luck, Jurgen

Sorry, wasn´t able to access AA for some days. Thanks for help, Rod!

I´m a little bit confused... see my PM dated Feb 14th to you :-) It runs, but I have no really experience with that and it would to be nice to get more infos. I´ve been successful with one of the archives found here on AtariAge. I burn the first 16 KB of the "BURNFILE" found in the attached archive and the computer starts. Without disk attached a "memo pad" with just a cursor on the upper left appears, otherwise it will boot from disk. Some of the keyboard commands will only work with RAMROD mod, so the system hang up whenm trying them (for example: RESET with SELECT = copy OS to RAM). I booted for the attached picture the XDOS dos and enter the monitor like described in the manual with RUN C001.