600XL U1MB installation

[Luigi301]

I'm the proud owner of a 600XL with 64KB of RAM and I'm installing a U1MB in it. I want to solder the four signal wires from the U1MB board in a way that it's not permanent, so I want to poke wires through vias on the board. I checked the schematics and traced the four signals over to easily-accessible vias over by the ANTIC. The vias closest to the CPU are under ICs. Is it safe to hook the U1MB up in this way? This is my first big console mod other than doing something similar to repair a blown diode on an Amiga.

Edited October 14, 2017 by Luigi301

[+DrVenkman]

I'm the proud owner of a 600XL with 64KB of RAM and I'm installing a U1MB in it. I want to solder the four signal wires from the U1MB board in a way that it's not permanent, so I want to poke wires through vias on the board. I checked the schematics and traced the four signals over to easily-accessible vias over by the ANTIC. The vias closest to the CPU are under ICs. Is it safe to hook the U1MB up in this way? This is my first big console mod other than doing something similar to repair a blown diode on an Amiga.

 

I've not done one in a 600XL but sure. Remove the IC from the socket, install the wire into the via and run it out the end of the socket then install the chip again. Shouldn't be a problem.

[flashjazzcat]

Doesn't really matter where you pick them up in my experience: you can take HLT from the via behind ANTIC and the rest from vias near the PBI connector if you like.

[Paul Westphal]

This was the next thing for me. Could you document this with pictures and post? ( The final working model ) Also, Which 64k mod are you using? I have the two wire PBI, / 1/2 resistor one.

[Luigi301]

I bought it modded from someone in the Marketplace. I dont know the specifics of the mod. Im also not sure where Im going to mount the U1MB inside the case - the keyboard ribbon is in the way of the two screw holes next to the joystick ports.

[Luigi301]

I was able to get it installed using vias that connect to the ANTIC but I haven't been able to fit it into the case as of yet. Right now it works but the wires and ribbon cables stick out of (and block) the cartridge port. The case is just too damn small. I'm thinking I can remove the PBI cover, put some insulation on the PBI edge connector, and just have it be a wart on the back.

Edited October 15, 2017 by Luigi301

[NISMOPC]

Also, Which 64k mod are you using? I have the two wire PBI, / 1/2 resistor one.

 

I bought it modded from someone in the Marketplace.

 

This is the 64k mod I did on the 600XL Luigi301 has. Three wire set-up..

 

[Kyle22]

It's ok to fold the ribbon cables. Just do it carefully so they are out of the way and don't interfere with anything. It will fit.

[mutterminder]

I have the U1MB installed in my 600XL. It seems to be working okay, but there are a few things that are puzzling me, I was able to update the date and time and save it okay. It remembers the extended memory setting and the system setting okay, but the other settings keep going back to default settings such as the BASIC slot, and the XEGS Game slot keep going back to CAR3. Also cartridges that are plugged into the cartridge slot don't work at all. Is there something obvious that I am missing or did I make an installation error? Thanks in advance for any help.

[flashjazzcat]

It setting aren't properly saved, look again at the installation, since it's not working correctly. Cartridges may be disabled by the PBI HDD / SIDE Hardware being enabled (depending on the BIOS in use, it's named differently).

[mutterminder]

Thanks. It was the SIDE hardware setting that was doing it. Once I disabled that, carts work normally again. I would like to update the BIOS now so that I can use my SIO to BT. In order to get the software loaded all I have is an UNO cart, an SDRIVE, and of course an Atari 1050. Can it be done with what I have, or do I need an SIO to PC?

[flashjazzcat]

SDrive will do the job just fine. Although I aim to release the next update shortly (somewhat overdue, and nearly one year after the prior update), I just added an ATR containing the necessary files inside the ROM folder of the current update package:

 

http://atari8.co.uk/wp-content/uploads/2015/12/Ultimate1MB_Firmware_Update_071216.zip

 

Check the README file as well. If you enable SDX and mount the ATR as D1: using SDrive, UFLASH should see all the files on drive 1. The safest way to proceed is to flash the "firmware" slot with "FIRMWARE.ROM", since that one-step procedure updates everything.

 

Be very sure that U1MB is saving settings properly first, though. Only when you're sure the hardware is behaving predictably should you proceed with an in-place flash update.

Edited November 19, 2017 by flashjazzcat

[mutterminder]

I think there is still something odd, going on with U1MB. Whenever I press the reset button on the 600XL, the system goes back to the default configuration, which appears to be:

1088K RAMBO

Stock XL

Disabled

Disabled

Disabled

Disabled

On with button

7

CAR3

CAR3

 

If I press Q to quit, it goes to Missile Command. I can change any of the settings and hit S to save. It seems to work if I just hit Q to quit, but if I press reset, it goes back to the default. I even put all of the update files on a MyDOS disk and when I loaded UFlash it was unable to detect the U1MB.

[flashjazzcat]

NVRAM isn't keeping the settings. I recall that the original BIOS writes the selected config direct to the hardware registers when you reboot via 'Q'. Reset always reads the config from the battery backed NVRAM. Try changing the battery?

[_The Doctor__]

picture of your install please

[Level42]

 

 

This is the 64k mod I did on the 600XL Luigi301 has. Three wire set-up..

 

0909171450_HDR.jpg

 

Are those humongous caps factory ??

[mutterminder]

I've posted two pictures. The first show's how it was during all the above posts. This shows not only how the U1MB was installed, but also what kind of 64K upgrade I have, I decided to revise the location of the U1MB wires so that they weren't attached directly to the CPU (also I didn't like how the solder connections looked) in case I want do a CPU upgrade. This, however did not seem to have any effect on the behavior of the board. Symptoms remain unchanged.

 

[+Roydea6]

Is the battery fitted properly under the two prongs for correct polarity.

[_The Doctor__]

where to begin? some of these caps are chipped with holes in them, some like the cap directly below U21 don't have the cap properly soldered in at all (look around leg to the right)

 

first order of business in my humble opinion is to fix the caps and fill suspect solder connections and cold solder joints

 

I would also make sure there are no shorts or legs that are touching either the board or the components next to the caps both green and ceramic..

Edited November 20, 2017 by _The Doctor__

[mutterminder]

You're right some of those caps do look kind of beat up. It hadn't occurred to me that it would cause any problems with an add in card, But perhaps there is enough extra noise with the added load of the U1MB that it is causing weird problems. It could hurt to replace some of those caps.

[_The Doctor__]

r46 looks funky and the rf modulation has been completely chopped out... personally I would de oxit the chips and sockets and re seat.. I wonder if this survived a flood and been re capped

Edited November 20, 2017 by _The Doctor__

[flashjazzcat]

Ribbon cables look somewhat tortured as well. I realise it's not practical for Lotharek to make the cables in anything other than generic lengths and orientations, which is why I have to keep a stock of connectors here for the construction of custom cables when installing these things. Just yesterday I discovered that the MMU ribbon on my own 800XL was faulty, and replacing it made the machine 100 per cent stable. As well as the abhorrent "2k14" headers on the U1MB, your MMU ribbon has no strain relief clip (just like the one I found to be flaky yesterday). It will not harm to continuity test the cables, and if you're feeling adventurous you could manufacture a new set and compare and contrast, so to speak. Even a break on RD4/5 on the MMU cable can cause all kinds of nightmares.

[Level42]

I wished Lotarek used the same connectors as are used on SOPHIA. Nice and low profile while still detachable.

 

I heard I need to order a new U1MB yesterday and Im going to ask if Lotharek can provide one without any connectors on the PCB....

Edited November 20, 2017 by Level42

[mutterminder]

Thanks for the help all, some of the detail in those pictures is false detail provided by the image processing from my phone camera. Under good light and a magnifier it doesn't look nearly as bad. But the disk capacitors did in many cases, because of the way they were factory installed, have one leg that ran across several traces.The component placement for some of the other parts is not very neat either. However, all of the solder joints looked good, even the cap below U21. I did lift the capacitor legs in some rather questionable cases though. The U1MB seemed to be working fine. It retained all of it's settings through a power cycle (at least 30 seconds off). It was detected by Uflash, so I was able to flash the new BIOS. Unfortunately, after that the unit no longer functions, so something went wrong. I had to remove it from the 600XL, which is now functioning normally as a 64K machine. I guess I'll have to re-flash the board through JTAG now. Maybe I'll put it in an 800XL instead, There is a little more space there.

[flashjazzcat]

Pretty much the outcome I expected. You don't need a JTAG cable to recover. You need a USB EPROM/flash programmer such as the TL866CS.