Has anyone built a FlashROM 99 on their own?

[CAJoeG]

I acquired five FlashROM 99 PCB's from PCBWay. I intend to build at least one FlashROM99 for my TI 99/4A since I don't have any cartridges or other storage devices for it.

 

Has anyone here in the forum ever built one? If so, what would be your suggestion to DO and NOT DO when I build one, and also for compiling and installing the software? I'm hoping to minimize my error rate during this project.

 

Project link: https://github.com/endlos99/flashrom99

 

Thank you!

 

Joe

 

[GDMike]

Are you sure you want a flashrom? Final Grom is probably what you really want?

 

[+jedimatt42]

I built mine when the github was released. I did not compile the software myself. I did get the jdec file from Ralph to flash instead. 

 

Otherwise it was pretty straight forward.

 

Watch out for the chip direction. 

I put my chips in sockets, but that then didn't fit in the 3D printable case that came out later. So I later ended up removing the sockets, and soldering the chips straight into the board. Today, I'd probably use sockets again, but design my own 3D printed case for it. 

 

I enjoy this sort of pcb/soldering project - it was nice when it came out, and the community enjoyed the benefits quite a bit. You will find that a number of the ROM images for it, copy EA5 programs up into an expected 32K expansion memory. But, there are plenty of direct-from-ROM images like those from Atarisoft that will work on a bare console.

[+jedimatt42]

Ah, yep, the avr/flashrom.hex file is in the github repo, so you don't have to compile it yourself.

[RickyDean]

9 hours ago, GDMike said:

Are you sure you want a flashrom? Final Grom is probably what you really want?

 

I would agree, but he's already got the FR boards. He just won't have all the usefulness. But he can sell off most of them and then have some FG99 boards made, and the experience soldering the FR boards will be useful.

[CAJoeG]

Thank you for all of the replies!

 

I've built several cartridges for my Commodore computers (VIC 20, C64, C16, C128, C Plus4, and PET 4016) in the past. So I'm very comfortable soldering on new PCB's. I also have some PCB's to build some Atari cartridges. My first one will be one with different versions of diagnostics that will be selectable via DIP switch. The rest will be similar, but with other programs.

 

I thought I saw the HEX file in the directory, but wasn't sure if that was the complied one or not. Thanks!

 

Thank you!

 

Joe

 

[CAJoeG]

A stupid question from a hobbyist, and not a person with an electronics background.

 

On the FlashROM 99 project, it lists a 470 Ohm resistor. I have 470R and 470K resistors in stock. Am I correct that the 470K is 470000 Ohms, and that the 470R is 470 Ohms? Thus I would use the 470R? The five color code for the 470R's that I have match the code for a five color coded 470 Ohm resistor (Yellow-Violet-Black-Black-Gold).

 

Just trying to not make a stupid mistake before soldering anything.

 

Thank you!

 

Joe

 

And yes, I will look into the FinalGROM 99 as well. I'd prefer a PCB where I can mount through hole IC's and resistors, rather than surface mount. But I have to learn SMD soldering at some point.

 

[+jedimatt42]

Yes, 470k is 470000 ohms. Most multimeters have 'ohm' meter mode. Most resisters are plus or minus a couple percent. 

[+FarmerPotato]

55 minutes ago, CAJoeG said:

A stupid question from a hobbyist, and not a person with an electronics background.

 

On the FlashROM 99 project, it lists a 470 Ohm resistor. I have 470R and 470K resistors in stock. Am I correct that the 470K is 470000 Ohms, and that the 470R is 470 Ohms? Thus I would use the 470R? The five color code for the 470R's that I have match the code for a five color coded 470 Ohm resistor (Yellow-Violet-Black-Black-Gold).

 

Just trying to not make a stupid mistake before soldering anything.

 

Thank you!

 

Joe

 

And yes, I will look into the FinalGROM 99 as well. I'd prefer a PCB where I can mount through hole IC's and resistors, rather than surface mount. But I have to learn SMD soldering at some point.

 

I think it's for the power-on LED, so not too critical.  But defnitely 470K is out of range.   You could use a 330 if that's what you had.

If you want confirmation, hook up this circuit:  a 3V coin battery, any LED and that 470 ohm resistor.  The LED should light up (if you have the LED in there right way round.)

 

+  ---|>---www--\
3V               |
-  --------------/

 

LED has a voltage drop of 0.7 (red) - 1.6 (newer colors) so the current is about 2.2 V / 470 = 5 mA.  Thats enough to light up common LEDs.  A bigger resistor will make it very, very faint!

 

 

[+FarmerPotato]

On 8/17/2024 at 12:48 AM, jedimatt42 said:

I enjoy this sort of pcb/soldering project - it was nice when it came out, and the community enjoyed the benefits quite a bit.

 

Yeah,  I was happy to use one of these for several years, and I still don't have a FinalGROM.

 

On 8/16/2024 at 8:44 PM, CAJoeG said:

Has anyone here in the forum ever built one? If so, what would be your suggestion to DO and NOT DO

 

OK, here's my tips.  I made all these mistakes the first time. 

 

 

1.  Use plain old 63/37 lead solder.  I decided to be smart and make this my first project with Tin/Silver 98/2.   It was no fun. 

2. I second what JediMatt said:

 

On 8/17/2024 at 12:48 AM, jedimatt42 said:

I put my chips in sockets, but that then didn't fit

Make the chips nice and snug to the board.  Don't use sockets.  Be gentle when putting it in the console, until you've got a case on it.  Later,  I shoved the bare board in, and the front row of chips were mangled.  Also, don't use lead-free solder.  Mine was unrepairable!

 

3. Get the MMC card slot on the correct side of the board.   I did that wrong the first time.   The kind I ordered were slung underneath.  I hate that. 

 

4. Use flux.