Tron with a D4 Error

ttbit

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Hello All,

I am new to the forum and glad to see something like this out here. I have been out of the loop for awhile on the "arcade front" and my son and I decided to tackle fixing our Tron machine. Some years ago I decided to clean the connections, as we had some intermittent issues and then we ended up moving in the middle of me having the thing apart. It had a lot of downtime between moves. I had no screen and no sound so I decided to leave it be for awhile.

Flash-forward to current time and I found that I had the monitor connector on the wrong set of pins. I also found that I had one of the ribbon cables misaligned (off by one pin on one side). Geeez. I usually pay pretty good attention to detail also. Maybe it helped that I have glasses now.

Here is what I have found:

- Cables plugged in correctly - Now get D4 Error
- Reseated all chips in sockets - D4 Error
- Ribbon cables have some bad connections checking over 4 ohms. Replaced. D4 error
- Found rom D4 had one error in it. Burned a new rom. D4 Error.
- Copied the old rom to a Mame install and was able to reproduce error, so I know the rom was bad.
- Had some Hitachi hn482764g-3 chips laying around so burned D1-D5 images to these and replaced. D4 Error

I purchased a Genius G540 to check and burn chips. What I have found is that this device will not read all of my 2764s correctly. If you read the chips in, a different checksum will show intermittently. Either the chips are weak, or this thing is going too fast, as these are -4 chips and it seems to do fine with -3. Erasing and burning the same chips do not work. It bombed on my d1 chip and now I am thinking that chip was probably fine and now I have an original part not usable. At first I thought almost all of my roms were bad. It took me awhile to find out that it was reading improperly.

Oh and get this....the one chip that reads the same EVERY time in my burner is the D4 chip! :) What are the odds? Actually the last two of the set check fine also, so I did not burn those.

I am amazed that everything I did produced the D4 error. I would be happy to see something different. Maybe I will yank the d2 out and see if I get a d2,d4 error.

5v supply checked consistent over all caps on the rom board. If anything, slightly high. I am using an older good Fluke Meter for these checks.

Any suggestions? I have not tried to print out the schematic yet. Reading it in the pdf was a little tough to follow. I thought I would bounce this here and see if someone else has run into this.

Thank you,
Don
 
BTW, Just pulled the D3 chip out and it showed d3,d4 error. At least I was able to get it to change. I burned another d4, for the heck of it. No change.

Oh, and my eprom eraser died. It only lasted about 60 minutes total use. It also was a Chinese model from ebay. I suggest not buying one of those.
 
You need to burn a D4 ROM for the correct ROM version. There are three common ROM revs, dated 6/15, 6/17 and 6/25. If the labels are gone or unreadable on your boardset, you'll probably have to burn all three and switch them out until you get the right one.
 
You need to burn a D4 ROM for the correct ROM version. There are three common ROM revs, dated 6/15, 6/17 and 6/25. If the labels are gone or unreadable on your boardset, you'll probably have to burn all three and switch them out until you get the right one.

Thank you. The date is 6/17. The compare was only 1 bit off, so I assume I have the right file, but I probably shouldn't assume. It was showing a 90 instead of a 94 at location 0x0FB4. I used the one from the MAME set. Oddly, the date on the mame set shows 6/14 for that file (6-14-pgc.rom). Comparing my rom to other roms in the mame set show it being greatly different. I also tried downloading a specific 6-17 set and the rom matched the MAME 6-14 file.
 
BTW, Just pulled the D3 chip out and it showed d3,d4 error. At least I was able to get it to change. I burned another d4, for the heck of it. No change.

Oh, and my eprom eraser died. It only lasted about 60 minutes total use. It also was a Chinese model from ebay. I suggest not buying one of those.

Curious, What make and model programmer did you buy?

I have an old Needhams pb10 that works great. It does need an isa slot so I have a dedicated computer for that. The GQ-4X is the one that most are going with now.

http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=gq-4x&_sacat=0&_from=R40
 
Curious, What make and model programmer did you buy?

I have an old Needhams pb10 that works great. It does need an isa slot so I have a dedicated computer for that. The GQ-4X is the one that most are going with now.

http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=gq-4x&_sacat=0&_from=R40

I have heard nothing but good about those Needhams. I took a chance and bought the Genius G540. The software crashes at times and it seems a little intermittent with these 2764's, but... I cannot say for sure if the problem is my old eproms, or the burner. I have it running on a laptop running Windows 7 64 bit. I ran it on a virtual machine using XP 32-bit and ran it on an older computer with Windows XP with the exact same results in all 3. I emailed them asking if they could modify the read cycles on the 2764, but no response.

I was going to purchase the GQ-4X, actually. I saw one new for $85.00 shipped but the next day when I went to buy, it jumped back to $95. I guess they were running some kind of special for that day. I wanted to play with the TTL testing that the G540 had, so I went with it. I am considering picking up an old parallel port burner too. I have an old PC that runs a CNC machine I built last year off parallel, so I will be keeping that machine for a long time.

I was looking at some EEproms late last night after my bulb wouldn't light on the eraser (glows at the ends though). I might try to pick up some Winbonds...

The more I think of it, I should just make an eprom burner. I turn into mega-nerd around this time of year. 2 years ago I wanted to learn C and play with Atmel processors so I bought an Arduino and made an Atari 8-bit floppy drive emulator. I enjoyed that. I learned soooo much and did so much more than I thought was possible. I just need an excuse to start a project.

Don
 
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