3 Apr
1999
3 Apr
'99
8:39 p.m.
On Sun, 28 Mar 1999, Tony Duell wrote:
Ah. Well, that pretty much leaves out everything I want to do this with,
because I don't have that kind of documentation. :/
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. 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(a)alcor.concordia.ca
http://alcor.concordia.ca/~ds_spenc/