[1200XL Boot Issues]

The two ROM/Ram bars are green.

[1200XL Boot Issues]

My 1200XL has suddenly developed boot problems. If I insert a cart and turn the computer on, I get a buzz like the one you would get if you were trying to load a cassette.  Occasionally, the cart will boot but not very often.  Also, If I press option and turn the computer on, it shows the Self Test screen as it should. If I press select, the self test jumps to the audio voice test.  If I press help, the self test menu screen flashes for a split second and the computer goes directly to the memory test. This computer has the 800XL/OnniviewXL operating system and a BASIC chip.  I haven't taken it apart to see if the OS chip has gone bad or if maybe SALLY is acting up.

[Omniview XL & Data Perfect on 1200XL]

There is also a patched version of AtariWriter Plus that will give you 80 column of Omniview but you have to have a 130XE or a memory upgrade compatible with the 130XE.

[800XL bypasses cartridge]

Considering that most of the computers I have bought were sold as untested and some as not working, the percentages are not so bad. I can remember 5 that I didn't or haven't been able to fix and I have probably done at least 50. I did ruin two 130XE boards before I bought a good desoldering gun.

[800XL bypasses cartridge]

This MB has some major problems somewhere, every time I check something, it acts differently.  Now it doesn't boot most of the time and when it does boot, it goes to self test.  Meanwhile, SYSCHECK says the memory is all good.  I have a 600XL that also doesn't boot but SYSCHECK says the memory is all good.  I am going to put them on the shelf until the summer and work on them on some of those days that are too HOT to go outside.

[800XL bypasses cartridge]

This is likely irrelevant but what is this mod. The first pic is the computer in question, the second pic is usual configuration.  The Yellow wire is part of the RAMBO mod.  Just in case you ask, I removed the mod and the computer still didn't work as it should.

 

[800XL bypasses cartridge]

I have used Star Raiders, Pole Position, BASIC, and PAC MAN.  All of them give the same behavior.  It seems as if something about the cart connection is making the computer think that the OPTION key is being held down.  Without a cart, the computer boots as it should.  If I attach a disk drive, the drive boots and I can load programs.

[Some new (not really) hardware made by tfhh]

Has anyone used the new version (4.5) of the 512K memory expansion and if so have you been able to select the 256K mode?

[800XL bypasses cartridge]

I was mistaken about bypassing the cart, I wasn't watching the screen and I was just going by the boot sound. The cart makes the computer boot to self test.

[Some new (not really) hardware made by tfhh]

My most important question was about the SETMEM.XEX. 

[800XL bypasses cartridge]

I have an 800XL that ignores any cartridge and boots as if there is no cart present. I have swapped out the SALLY and there was no difference.

[Wanted: ICD RAMBO XL Schematic]

I have a 1200xl that has been modified to have the 800XL OS ROM and internal BASIC. If I install the RAMBO, do I follow the 1200XL instructions or the 800XL instructions?

[Some new (not really) hardware made by tfhh]

When I run the tool that has SETMEM.xex nothing happens. I press start and the screen blanks and returns to the original screen. I can't get to DOS or enter any commands.

[Some new (not really) hardware made by tfhh]

I have modified my 1200XL and it now has the 800XL operating system, should I attach the brown wire according to the 1200XL instructions or the 800XL instructions?

 

[600XL Trouble shooting]

I switched all of the ICs from the non booting computer to a working computer and vice versa. The working computer still works the non worker still doesn't boot. The problem must therefore be in the circuitry. There is no obvious problem with caps, resistors, or soldering and it is going to be time consuming to find the obscure problem.

[600XL Trouble shooting]

I am planning to upgrade the RAM and do the Complete video upgrade. If I can get it working.

[600XL Trouble shooting]

This computer will not boot. I have tested every IC on the board and they are all good. I got it to boot twice with Star Raiders but the video was unstable and after a few minutes the screen turned to video garbage. It gives video when I use the syscheck. I know that syscheck isn't intended for the 600XL but it does indicate that the components of the video circuit are OK. Occasionally, when I turn it on there are some moving colors on the screen. If I knew which components were bypassed by the syscheck, I could at least narrow the search.

[600XL Trouble shooting]

Not Booting

[What's the latest Atari related thing(s) you've bought on ebay?]

Another 600XL, untested. The computer works perfectly. I am amazed at the video quality on the 600XL. The RF picture on this one is better than the composite of most 800XLs.

[SDrive-ARM preorder]

Is it still possible to purchase the Sdrive-ARM?

[What's the latest Atari related thing(s) you've bought on ebay?]

Untested 600XL, I will clean it up, hopefully get it working, then upgrade to 64K and do the Supervideo mod.

[Some new (not really) hardware made by tfhh]

I found the link to the newer version instructions.

 

Version V4.0, V4.1 and V4.2: http://www.van-radecke.de/SRAM/512KB_SRAM_Expansion_V4_2.pdf

Version V4.3: http://www.van-radecke.de/SRAM/512KB_SRAM_Expansion_V4_3.pdf

Version  V4.4: http://www.van-radecke.de/SRAM/512KB_SRAM_Expansion_V4_4.pdf

Version V4.5: http://www.van-radecke.de/SRAM/512KB_SRAM_Expansion_V4_5.pdf

[Some new (not really) hardware made by tfhh]

I just attempted to install one of my 512K memory expansions into a 1200XL.  When I prepared to install the wires, I noticed that my version has four wires instead of three.  I decided to ignore the extra (ORANGE) wire and follow previously published instructions.  That did not work because the computer will not boot in the present configuration.  Are there any new instructions that I missed somewhere in this topic. My attempted installation is shown in the picture.

[Another 130xe memory issue]

I found my problem. I did continuity checks on the DRAM pins and found a break on each bank. Likely a broken trace. After adding jumper wires to bridge the bad spots there is another 130XE ready to reenter society.

[Looking for help with my 65XE (boots direct to memory test)]

I found the problem, there was a disconnect between the 25953 and the MMU. I desoldered the socket and there was a badly damaged solder ring so I soldered in a connecting wire and everything worked.  I also pulled the BASIC chip and replaced it with a 24 pin BASIC chip just to improve the appearance.