Mmm, nice EPROM programmer !

[Etienne MacGyver]

I dont know where the HDD is located in that unit, but with a miniata or sata to USB it will show as a standard usb disk on another pc.

That could also be a option to transfer the roms in bulk to the hdd.

[level42]

Mmm, the rom files are only a couple of kB each. Even on an old 1.44 MB floppy you can scram LOADS.of ROMs on one disk, but that will hardly ever be necessary...

Well, maybe I can hook up a RS-232 cable and use Kermit to transfer the files between the two PCs..... LOL !

I did read that someone had succes by running a VMWARE Linux session on a Windows PC and in that Linux session he ran a DOS emulator.....and that worked while running the Needham EMP-10 software directly didn't work, even in a DOS-Box......kinda funny.

[Etienne MacGyver]

serial cable is an option, or good old Fastlynx (i might have the cable still here)
much more reliable than floppy 

[level42]

Of course....

I just succesfully burned a test 2716 without any problems. It's not exactly fast but WDF....as long as it works and is reliable.....

Sooooooo, I wanted to do some REAL stuff and pulled out the PCB from my Asterock. The reason ? John on the Vecttor list figures out a small patch for 1 of the EPROMs to make the game "Freeplay". This would make it possible to remove the credit button on the coindoor so Of course I wanted to try it.

Only two bytes need to be changed.....

When I looked at the PCB I had a bad feeling......that is a whole lot of EPROMs there !
8 pieces.....and Asteroids isn't such a big game......so I feared.....and Indeed: the board uses 2708 EPROMs.....
I had to think of a very famous Alanis Morissette song........

[anunaki]

Andre, not sure if this is a good one. But I post it anyway:

http://www.ebay.nl/itm/EPROM-Programmer-Universal-Adapter-Commodore-PET-ROM-MPS6540-2708-2513-2332-2364-/261097867410?pt=LH_DefaultDomain_0&hash=item3ccaa54892#ht_771wt_1397

|It says you can programm 2708's with it. It says you can programm all the old stuff with it. It's an adapter, so you'll need an programmer. But you already have one.

Maybe it's something for you

Greetz, Patrick

[level42]

Thanks for the tip Patrick, but with these things you gotta read very carefully exactly what it can do.....


It can _read_ those EPROMs, but nowhere it says that it can program them....which is also pretty much impossible....

[anunaki]

Ow ok, i assumed it was a programmer adapter and wanted to tip you so you could check it out.

Too bad it isn't.

Can you explain why it is impossible?

[Laszo]

You can use 2716 to replace 2708's look it up on the internet.

[level42]

Ow ok, i assumed it was a programmer adapter and wanted to tip you so you could check it out.

Too bad it isn't.

Can you explain why it is impossible?

Well, maybe not impossible but it would require you to apply +12V and -5V to certain pins of the 2708 during programming. You'd at least have to bend out those pins on the 2708 so they won't contact the ZIF socket of the programmer. Next you need to apply these voltages externally. However, I'm not sure if this can be done safely and I have found no info about doing this except for reading 2708's.....

Thanks Leo incidentally I was already working on it

I tried it yesterday in my Asterock but it stayed frightfully dead....
I have a feeling the info I got how to re-wire certain pins was not completely correct.
I've found different info about this on different sites....

SO.....I studied the datasheets of the 2708 and 2716 and also the Asterock Schematics (all found on www.andysarcade.de, very nice )

Using this info I came to this:

Maybe someone (Andreas ?) can confirm what I think it should be is correct or not:

1) Pin 18 is "Program" on 2708, /EP on 2716. The 2708 and 2716 manual say this line must be Low for read operation. The Asterock schematics are not fully clear, but it looks like all pin 18's on the EPROMs are tied to GND already (WILL CHECK THIS), so this would be OK to leave as is.
2) Pin 19 is Vdd (+12V) on the 2708. It is address line A10 on the 2716. This has to be lifted and tied to GND (pin 12) if the data is in the lower half of the 2716, or to Vcc (+5V, pin 24) if the data is in the higher half of the 2716 address space.
With a switch between these two I could make it possible to make the free-play switchable, but I see very little reason for it....
3) Pin 20 is /CS-PE on the 2708, /G on the 2716. These seem to work as Chip Select for reading on both 2708 and 2716 as far as I can see, so in theory this could stay untouched too....
4) Pin 21 is Vbb (-5V) and Vpp on the 2716. We definitely don't want -5V anywhere on the 2716 so this leg should be lifted. The 2716 datasheet's table says it should be at Vcc (+5V) for reading so it should be bridged to pin 24
5) all the other pins are matching so can be unchanged.

Summing it up, for Asterock I'd need to:
a) lift pin 19 and short to pin 12
b) lift pin 21 and short to pin 24

But first I'lll put back in the old 2708 to see if my board actually still works...

[Etienne MacGyver]

With a switch between these two I could make it possible to make the free-play switchable, but I see very little reason for it....

Why not just implement that as a jumper, you never know where your games will end up if you let it go some day.
maybe the next owner likes to coin up 

It does give that real feeling of arcade playing to throw in a coin / token ..

[level42]

With a switch between these two I could make it possible to make the free-play switchable, but I see very little reason for it....

Why not just implement that as a jumper, you never know where your games will end up if you let it go some day.
maybe the next owner likes to coin up 

It does give that real feeling of arcade playing to throw in a coin / token ..

Well, if that happens (in theory, it actually is already sold....) I still have the original 2708 EPROM and it can be very simply put back in it's socket

[level42]

Put back the original 2708 and Asterock still works 100%

I just checked and pin 18 of all 2708's are indeed connected to GND so it looks we're all set to try my idea...

[level42]

Success !!!! Freeplay on Asterock

Since pin 18 is wired to GND on the Asterock PCB I shorted pin 19 to 18 instead of 12 because they are next to eachother and so easier to short...

So the final instructions:
a) lift pin 19 and short to pin 18
b) lift pin 21 and short to pin 24

That's all there is to it. Of course if you want to exchange all 2708s into 2716s it's better to mod some lines on the board instead but if its just one like this this is the easiest way.

The hack does show some weird effects.
After power up the number of credits is 00. However P1 was blinking but not P2. Tried P2 anyway and it does start a two player game just fine. After killing off all ships on both players the credit number showed 98 now.
After a P1 game the number Was 97. Etc etc etc.
Not sure what will happen if it reaches 0, but hey, I rarely play 100 games after another....

Ok drifted off a bit from the original subject.....

On UKvac Raven reported he owns a Batronix programmer and it works just fine, no problems with burning chips that need +25V contrary to some other USB programmers.

[Laszo]

Nice problem solved.

[level42]

Nice meeting you yesterday Anunaki !

Does MK2 use 27080 EPROMs or are those the one's you need ?

I just checked the list of supported devices by my Needham programmer. There is an Atmel 27C080 listed so yes I can program that.

Or check for yourself =>  http://www.arcadesolution.com/emp10dl.pdf

I mean the device cost me 100+ and I need to make some adapter myself risking to blow it up

The first thing I want to do with it is OK, I have the needed EPROMS to programm 4 different MK2 revisions.

On the other hand, I don't want to buy some Chinese crap.

I think about it and get back to you.

ISD there any change we will get 5 people to buy one?