On Sun, 28 Mar 1999, Tony Duell wrote:
> To _read_ a ROM, you don't really need an EPROM programmer.
No, I suppose I don't.
The easiest home-baked solution for me would be using my VIC-1210 3K RAM
Expander. IIRC, it has space for a couple of ROMs on the board, which I
think were intended to the SuperExpander cartridge (is that the name? The
one with the extended BASIC with graphics and sound commands). Two of the
2114 SRAMs are dead, so I have to mess with the thing anyway. I could
install some ZIF sockets for the ROMs, and later when I get an EPROM
burner, I could grab all the game images from the 'net and play them on
genuine VIC hardware.
One important question: Are ROM and EPROM pinouts standardized? Would a
reader have to change what it's doing for different ROMs?
I'm not sure how many address lines the VIC-1210 has hooked up to the ROM
lines.
> As regards commercial solutions, there are/were stand-alone EPROM
> programmers. They have a little keypad to read/program the EPROM, etc.
> Most of them have a serial port to link to a PC (or any other computer
> for that matter), and they often upload/download intelhex files.
That would be ideal. And I wouldn't have to use a PC, either. :)
Does anyone know where to get something like this >today<? And for a
reasonable price? (Less than $100, say.)
A lot of my machines are getting to that age where I'm worried they'll
forget stuff. And there's even a few things that I've never powered up,
with EPROMs of undetermined health in them, which would be good to store
and fun to poke around in, before applying power.
> > Also, how would one go about reading or writing to an EPROM that is
> > soldered to the printed circuit board? Is it possible to clip onto a chip
> > from the top and have it work that way? I have some machines with
> > unsocketed EPROMs, as strange as it sounds.
>
> Well, if you can tri-state (force to high impedance) the address line
> drivers on the board (so the EPROM lines aren't being drive), then you can,
> indeed, clip something on the chip. I did that on the RX02 drive, where
> there's a signal shown on the printset specifically to tri-state the drivers.
Ah. Well, that pretty much leaves out everything I want to do this with,
because I don't have that kind of documentation. :/
> Otherwise you have to unsolder the chip and stick it into an EPROM
> programmer. Unsoldering an irreplaceable chip is a little stressful at
> first, but you get used to it ;-)
Ugh! :)
Obviously I'll put sockets in before replacing the chips so that this
won't happen with the same machine twice. :)
--
Doug Spence
ds_spenc_at_alcor.concordia.ca
http://alcor.concordia.ca/~ds_spenc/
Received on Sun Apr 04 1999 - 04:39:04 BST