REV 5 BOM and Build/Install procedure

[Elethiomel]

I now have DiagROM flashed on to a cart and working. I was planning to socket the CPU on one of my boards so I'll do that now. It wont' be the final board I'll use, but it will do for now.

[Elethiomel]

The CPU is now socketed and working AOK. I've decided to do some other upgrades as I'm thinking that I may actually use this C103253 based system on the actual project. The CPU is in completely the wrong spot as the ST536 would interfere with the MMU and the keyboard support post from the case. This is actually an opportunity for me to learn Kicad better and to order my first custom PCBs for a simple CPU relocator project. The ST536 seems like it would fit perfectly over the RAM on this board. Even if the constituent parts of the project doesn't work out, it will be a learning experience in terms of PCB design and SMT soldering.

New parts bought from the Exxos store to kick this project system up a notch:

030 CPU heatsink
9 PIN SIL RESISTOR 2.2K - PACK OF 5 (Bus pull-up mandatory fix)
PSU REPAIR KIT MITSUMI SR98 240V
TOS162 / TOS206 ROM
ST/F/M / MEGA ST-RAM 4MB UPGRADE
4MB UPGRADE SHIFTER PCB ONLY
15CM RAM CABLE

I've also ordered a PLCC42 socket for the ROM from mouser : https://www.mouser.co.uk/ProductDetail/ ... ceYQ%3D%3D

[Elethiomel]

Well, after a good half hour spent aligning the CPLD under a microscope, I held it carefully in place, used some flux, some more flux and then added a bit of flux. I then drag soldered, checked for bridges, removed a few with some braid and carefully reflowed the solder. After a bath in some IPA, some scrubbing with a toothbrush and another bath, I did a final inspection under the microscope. Everything looked good so I soldered on the PWR2 and JTAG pins.

I then set up a spare raspberry pi as a JTAG programmer by following this tutorial : https://linuxjedi.co.uk/2021/11/25/revi ... pberry-pi/

I hooked up some DuPont cables to connect the JTAG port to the GPIO pins, and powered the PWR2 connector directly from pin 4 which is one of the Raspberry PI's 5v output pins. No magic smoke, no chips getting unexpectedly too warm.

Let's see if the programmer detects the device.

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root@raspberrypi:/home/pi# xc3sprog -c sysfsgpio_creator -j
XC3SPROG (c) 2004-2011 xc3sprog project $Rev: 774 $ OS: Linux
Free software: If you contribute nothing, expect nothing!
Feedback on success/failure/enhancement requests:
        http://sourceforge.net/mail/?group_id=170565 
Check Sourceforge for updates:
        http://sourceforge.net/projects/xc3sprog/develop

JTAG loc.:   0  IDCODE: 0x59608093  Desc:                      XC95144XL Rev: E  IR length:  8

OK, this looks very promising! The XC95144XL is being detected!
Time to grab some firmware.

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root@raspberrypi:/home/pi# wget https://www.exxosforum.co.uk/atari/last/TF536/ST2A_144XL_H4.zip
--2022-03-27 21:06:42--  https://www.exxosforum.co.uk/atari/last/TF536/ST2A_144XL_H4.zip
Resolving www.exxoshost.co.uk (www.exxoshost.co.uk)... 81.4.101.12
Connecting to www.exxoshost.co.uk (www.exxoshost.co.uk)|81.4.101.12|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 11037 (11K) [application/zip]
Saving to: ‘ST2A_144XL_H4.zip’

ST2A_144XL_H4.zip                       100%[=============================================================================>]  10.78K  --.-KB/s    in 0.001s  

2022-03-27 21:06:43 (7.13 MB/s) - ‘ST2A_144XL_H4.zip’ saved [11037/11037]
root@raspberrypi:/home/pi# unzip ST2A_144XL_H4.zip 
Archive:  ST2A_144XL_H4.zip
  inflating: main_top.jed 

OK, time to program.

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root@raspberrypi:/home/pi# xc3sprog -c sysfsgpio_creator -v -p 0 main_top.jed 
XC3SPROG (c) 2004-2011 xc3sprog project $Rev: 774 $ OS: Linux
Free software: If you contribute nothing, expect nothing!
Feedback on success/failure/enhancement requests:
        http://sourceforge.net/mail/?group_id=170565 
Check Sourceforge for updates:
        http://sourceforge.net/projects/xc3sprog/develop

Using built-in device list
Using built-in cable list
JTAG chainpos: 0 Device IDCODE = 0x59608093     Desc: XC95144XL
Device is blank
Programming Sector 107.                            
Programming  time 15303.6 ms
Verify Sector 107
Success! Verify time 1473.9 ms

Sucess! It programmed and verified! I'm more than a little pleased with this. I did NOT expect the soldering process to go well at all!
The next step is to get the RAM installed, and to wait patiently for my PLCC socket and ROM to arrive from Exxos and mouser respectively.

[Elethiomel]

This is becoming more of a build diary than "Help, help!" (although I'm sure that will come soon). Hopefully it will be useful to someone in the future.

RAM, and all headers installed. Just the ROM and its socket to go.

[Badwolf]

Sucess! It programmed and verified! I'm more than a little pleased with this. I did NOT expect the soldering process to go well at all!
The next step is to get the RAM installed, and to wait patiently for my PLCC socket and ROM to arrive from Exxos and mouser respectively.

Excellent work Elethiomel. Especially sweet success if it's the first one you've ever done!



BW

[Elethiomel]

Thanks BW and congrats on your success with the DFB1r5 and the FPU! My thirst for a Falcon increases daily

I've now got a bag of Exxos goodies and and just awaiting the mouser parts.

[Elethiomel]

The mouser parts arrived.

On the PLCC socket, I punched out the bottom plastic piece so I could access the pins from the top. This socket had two small posts for mounting alignment, so I had to trim them off too. Soldering this in was a bit of a PITA as the angle was too tight for my K tip and I had couldn't do a proper drag. I also accidentally touched the inside sides of the socket once or twice melting them slightly, which required some careful cleanup. Two solder bridges also required some very careful iron work. I then installed the ROM

After cleanup and a final sounding out of pins, I then moved on to installing the CPU in its socket. Even though the pins all looked straight, it took forever and some micro adjustments to get them in to the socket. I don't think I'll be taking that CPU out any time soon.

Everything looked fine so I removed my 68000 from its socket and went to install the card. Whoops, I had soldered on 2 rows of square header pins and I needed round! Luckily I had some on hand and after carefully desoldering 64 pins, I installed the new round strips.

My motherboard really isn't the right one for this card as it would interfere with the central case post and a 4700uF cap, but I'm going to sort that out later. In the meantime I installed a stack of 64 pin DIL sockets so the card would clear the MMU and the capacitor, pulled the existing motherboard ROMs, grabbed my trusty Exxos PSU and flicked the switch...

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ATARI LOGO!
Memory Test:
ST RAM 512KB RAM
Memory Test Complete.
A rather long black bar counting down and Desktop!

The mouse works and I can click around on the desktop


Now here's an odd thing though. When I attempt to boot the ST v4.4 diagnostic cartridge I get the following

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I6 Testing Bus Error handling
No (I6) error


I7 Bus error not detected
EA Address Error  Access Address: FA6A98 Program Counter: 6DF7EE

E8 Exception error

The address and Program Counter are consistent between reboots.

My config is a bit odd though. Is it possible that the ST536 has never been tested on a 512KB machine? I know there must be some address decoding going on in the CPLD. Maybe it assumes a 1MB or 4MB machine? After all, 512KB with a 68030 is a bit silly I do have an Exxos 4MB kit waiting here to be installed.

Of course, it could just be (and it's much more likely) that I mucked something up.
Any help/input appreciated.

[Elethiomel]

This machine when I bought it came shipped with a surprise : A Marpet with 2 SIMMS installed, giving me a whopping 1MB of RAM.
To test my 1MB or 4MB hypothesis, I removed the ST536 and reinstalled the Marpet.

Same issue. Hrrm. Maybe 4MB? ( I know, grasping at straws here )

1MB of ST-RAM is detected on boot at least now, so I can run GemBench from my cartridge

20220330_235659.jpg (565.78 KiB) Viewed 1856 times

Not too shabby at all! I wonder what's going on with the Diagnostic cart? While I'm playing with things I might see if I can flash an EmuTOS ROM.

[Elethiomel]

Wait, it looks like exxos had the exact same issue! https://www.exxosforum.co.uk/forum/viewt ... =50&t=3894 and it was mentioned that "You can not use the Atari cart diagnostic if the machine is not original (CPU, TOS etc.) ...". Given that the machine passes a RAM test and GemBench is working, it sounds like I may actually be OK.

I think it's time to play with EmuTOS, Alt-RAM etc

[Elethiomel]

4MB Exxos Kit installed. System booting AOK and passing memory tests. Just for completeness : The diagnostic cartridge issue does not go away with 4MB of RAM. I think we knew that already, but I just want to 100% confirm it

Regarding EmuTOS, it seems my Minipro-TL866A clone can't correctly read the AT27C4096 ROM correctly. I'd like to back it up, then flash EmuTOS and TOS2.06 on it. Looks like I'm not the only person to have had this issue though : https://blog.troed.se/2020/07/22/plcc-4 ... ith-tl866/. I'll try bridging the connectors as suggested tomorrow.