Re: mystery ROMS

[Nama <forums6000@mac.com>]

On Aug 6, 10:26 pm, demp...@actrix.gen.nz (David Empson) wrote:
> Nama <forums6...@mac.com> wrote:
> > I have some ROMS that came with some Apple II hardware that I recently
> > purchased, and were in a box with some original integer ROMS.
>
> > These ROMS/EPROMS have white stickers on the top and are labled as
> > follows:
>
> > A2  1.0
> > G2  V2.2
> > G3  2.0
> > G5  2.0
> > G7  2.0
> > G8  2.0  1331405
> > G10  2.0
>
> > Would anyone have an idea what they could be?
>
> What physical size are they, and how many pins on each chip?
>
> In particular, are they the same width as typical TTL logic chips (about
> 1/4 inch), or as wide as typical EPROMs (about 1/2 inch)?
>
> The former type may be fusable link PROMs (like used on the Disk ][
> controller) or PLDs/GALs or similar logic chips.
>
> The latter type may be PROMs or EPROMs.
>
> Can you see (without peeling off the labels) whether they are made of
> plastic or ceramic? Ceramic chips are likely to be EPROMs, while plastic
> ones are not (plastic can't withstand the heat from a UV lamp when the
> EPROM is being erased).
>
> Assuming they are half an inch wide and 24 pins per chip, they could be
> a set of alternative ROMs for the Integer/Applesoft ROM card, which
> holds six 2Kx8 PROMs (or 2716 EPROMs). They might be custom firmware of
> some kind.
>
> The A2/G2 ROM might be alternatives for the F8 ROM position, which
> normally holds the monitor firmware and always has the reset vector.
>
> --
> David Empson
> demp...@actrix.gen.nz

Ok, so they are all ceramic, so I guess that means they are all
eproms.

Can I damage anything by putting them in a ROM card and seeing what
happens?

P